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What Is Building Science?

Introduction to Building Science

Civil engineering is the main branch of engineering that is concerned with the construction of buildings and other structures. But civil engineering alone is not implemented in the construction of buildings. Various other streams of engineering like mechanical engineering, soil engineering, aeronautical engineering, etc are also equally involved.

To illustrate the involvement of other streams of engineering in building sciences let us take an example. When a dam or a very tall skyscraper is built, first the construction site is thoroughly analyzed for the nature and type of soil or ground, the level of the water table is checked, the seismic zone under which it comes is checked so that the building is built accordingly making it resistant to earthquakes to a certain extent; simulation tests are carried out in labs to check how stable and safe the structure will be once it is constructed and likewise so many other tests are done before the first brick is laid. Thus soil engineering, mechanical engineering and various other branches of engineering play a vital role along with civil engineering in the construction of buildings. Together they are called building sciences. Therefore building sciences are concerned with ensuring that various parameters are taken care of and dealt with, before and while a building is being constructed. This article focuses how various engineering streams play an important role in building sciences.

A Real Life Example of the Application of Building Sciences and How Other Streams of Engineering is Vital in Building Sciences:

Taipei 101, the world's second tallest building uses mass dampers for the stability of the building. For such a humongous structure, its stability plays an important role and so does safety and the investment of millions of dollars. The usage of mass dampers ensures this to a certain extent. Before the construction of the building, the ground was tested for how soft the ground was and whether it was sensitive to many seismic activities or not. While the building was being constructed, it was designed in such a way that the airflow around it is good and it doesn't make the building sway too much and cause too much strain on various parts of the building. Thus mechanical engineering, aerodynamics, soil engineering and other sciences too were involved while the building was being constructed. This is what Building Sciences are all about.

How Various Engineering Streams Play a Vital Role in Building Science? The various factors of that affect the buildings are:

Stress and Strain: The buildings are affected by naturally occurring phenomenon like winds at high speeds, storms, torrential rain, flood, etc. When this happens, the stress and strain experienced by the building is increased significantly. So building sciences use mechanical engineering to simulate the stress and strain experienced by the building and thereby use appropriate construction materials while constructing them thereby ensuring that the stress and strain on the building don't lead to any significant damage to the structure and damage it.

Stability: The center of gravity of the building should lie low so that the building doesn't start leaning and eventually lose its stability. Leaning tower of Pisa is a perfect example for this case. It is one of those cases where building sciences were not implemented and that led to the building being not stable and causing it to lean. The reason behind it is the ground on which it is built is very soft for such a huge structure which has led to its leaning position. Modern advancements in building sciences have led to the restoration of the angle of the building so that it doesn't tip over.

Resistance to Earthquakes: The Bird's Nest, which hosted the 2008 Olympics had a unique structure at its base so that it could resist earthquakes of high degrees. The foundation was engineered in such a way that a major part of the vibrations are damped and isolated at the foundation itself and is distributed uniformly so that the disturbances or vibrations do not affect the building as a whole. Principles such as base isolation and dissipation systems are used to prevent any damage of high degree from minor earthquakes.

Aerodynamics: While constructing bridges over rivers, like the Hangzhou bay bridge which is affected by winds at high speeds, the components used while building the bridge are designed in such a way that the flow of air around the bridge is fluid and it doesn't resist the air flow around the bridge. Thus the bridge is rendered safe and doesn't sway when the speed of wind increases.

The Mechanical Strength of the Structure: When buildings and structures are built, the mechanical structure of the building is very important as this is what forms the skeletal structure of the building or a structure. Every other component and part is built over this mechanical structure. Eiffel tower and Milau bridge are excellent examples of the efficient integration of civil and mechanical engineering. Eiffel tower built in the late 19th century is still standing and thanks to some really good implementation of mechanical engineering, it is not bothered by any natural disasters except for a few wear and tears that have been checked and restored.

There are many other structures that are standing and are great examples of building sciences but they are out of the scope of this article as this is just an overview of what building sciences are and why, where and how they are applied.

Thus building sciences are very important in today's world in the construction of a building irrespective of its size.

Geometry of Bridge Construction

The four kinds of bridges and some combinations

A. The beam or truss bridge is, in effect, a pair of girders supporting a deck spanning the gap between two piers. Such a beam has to withstand both compression in its upper parts and tension in its lower parts. Where it passes over supports, other forces come into play. A beam may be a hollow box girder or an open frame or truss.

B. An arch bridge can be designed so that no part of it has to withstand tension. Concrete is well suited to arched bridge design. When reinforced concrete is used, a more elegant and sometimes less costly arch can be designed and most concrete arch bridges are reinforced.

C. A suspension bridge consists, basically, of a deck suspended from cables slung between high towers. The cables of high tensile steel wire can support an immense weight. The towers are in compression and the deck, often consisting of a long slender truss (used as a hollow beam), is supported at frequent intervals along its length.

D. A cantilever bridge is generally carried by two beams, each supported at one end. Unlike a simple beam supported at both ends, the cantilever must resist tension in its upper half and compression in its lower. A fifth type arrived on the scene in 1952 the first modern cable-stayed bridges were built in Germany and Sweden. There are also many other composite forms of bridges. The bridle-chord bridge is a combination of a long beam (usually a trussed girder) partially supported by steel wires from a tower at one end, or from towers at each end. Most cantilever bridges are designed so that a gap remains between two cantilevered arms that reach out from their abutments: the gap is bridged by a simple beam.

Some Examples

History Of Bridges

Bridge study has revealed that people have been carrying out bridge construction since humans first assembled into groups. The initial bridge design was basically felled trees that were utilized for moving over the ditches and rivers, and concrete bridges were rare. With the advance of civilization, techniques were discovered to use rocks, stones, mortar, and other materials for the creation of stronger and extended bridges. Subsequently, as the engineers and physicists advanced in the design, materials, and construction technology, modern materials like steel and aluminum were introduced for bridges.

Bridge Construction during 20th Century

The bridge construction skills progressed rapidly during the 20^th century. At the end of the century, new techniques were developed that improved the design, strength, and durability of the bridges. Steel bridges were strongly riveted instead of the previous practice of using bolts. Concrete bridges were being cast at the desired place, instead of being precast. Huge bridge elements made from bars and small sections were used, and not rolled as one part. Before the 1980s, the majority of bridge designs included expansion joints for decks, including expansion and fixed support bearings. This technique was used to permit structural expansion and contraction. However, the expansion joints are likely to be filled with debris, and bearings often weaken over time. Thus, the structure is hardened, and maintenance requirements are increased. The bridge engineers explored methods to reduce this trouble, and finally the expansion joints and bearings were eliminated to develop a joint-less bridge. This type of bridge is constructed on a flexible foundation that may expand or contract with negligible trouble.

Modern Bridge Construction Techniques

New technologies are expected to meet the challenging and varying requirements, and also offer options that will guide to innovative engineering and bridge construction standards. With the beginning of the new century, bridge construction is being revolutionized. Modern construction methods and the latest advanced materials are being evolved. Construction technologies like post tensioning, reinforced ground walls, and soil freezing are being developed. Modern surveying techniques are being used that have facilitated the soil selection, and other design parameters, through the use of optical and infrared technology. Progress in the deck technology is creating lighter and stronger decks. Bearings, joints, and seismic elements have become more effective since advanced testing facilities have been introduced. Consistent, economical, fast, and programmed inspection systems will emerge.

New Bridge Construction Materials

Materials with improved characteristics will be used that will make the bridge construction safe, durable, and reliable. Materials like high-performance concretes, polymer concretes, and plastics will be utilized. As the fiber reinforced composites are becoming more tolerant towards temperature, they will be used extensively for bridge construction. Use of larger steel fibers will be used in the tensioned members. The economics of future bridge construction will implement a simple design, with an increased interface between design, erection, and maintenance. Progressive study in modern superior materials and management techniques will facilitate the construction of durable structures that do not require extensive maintenance.

Stillwater Bridge

The Stillwater Bridge, featuring a counterweighted, cable-and-tower design, embodies engineering significance as a rare surviving example of vertical-lift highway bridge construction of the Waddell and Harrington type. The significance of the Stillwater Bridge is best evaluated within the general context of Minnesota and Wisconsin movable highway bridges.

Historic Significance

Movable bridges, also known as drawbridges, are constructed over navigable waterways when it is impractical or uneconomical to build fixed bridges of sufficient height to permit the passage of vessels. Human ingenuity has devised numerous systems for lifting, dropping, folding, rotating and retracting a span to provide temporary clearance. By the early 20th century, however, engineers had focused their attention on three, basic drawbridge categories: swing, bascule and vertical lift. Briefly defined, a swing span revolves in a horizontal plane around a vertical axis, a bascule span rotates in a vertical plane around a horizontal axis and a vertical-lift span rises and descends in a vertical plane.

In Minnesota and Wisconsin, as well as elsewhere in the nation, virtually all 19th century movable bridges were of the swing-span variety and the type continued to be constructed during the early 20th century. As late as 1935, a total of 51 highway swing spans were in operation in the Minnesota and Wisconsin. Not one of these structures survives. The demise of the highway swing span was nation-wide, reflecting its growing incompatibility with an urban setting. There were two basic problems with swing spans. First, the central pivot pier increasingly became an obstruction to navigation for the ever-larger vessels of the late 19th and early 20th centuries. Second, the swing span itself squandered valuable space. By requiring a clear turning radius, it prohibited the development of docking facilities adjacent to the bridge site. These shortcomings were especially onerous along highly industrialized urban waterways, where shipping channels tended to be narrow, highway crossings numerous and real estate prices high. For less crowded sites, the swing span remained a viable form of technology well into the 20th century, Most surviving swing spans, for example, are railroad bridges in rural regions or in relatively uncongested urban areas. But in the downtown waterfronts of late 20th century American cities, the swing span was marked for extinction. Its major adversary was the federal government.

No matter how loudly shipping and real-estate interests might denounce the swing span, there was no effective means of regulating movable-bridge design until the early 1890s, when Congress authorized the War Department to approve plans for all new bridges over navigable waterways and to seek the alteration of any existing bridge that interfered with "reasonably free, easy and unobstructed" navigation. In 1892, the War Department sent a clear message of future policy by way of Chicago, demanding the removal of a two-year-old swing span from one crossing of the Chicago River and denying permission to build a new swing span at another. The search for an alternate drawbridge technology began in earnest. Not surprisingly, Chicago was in the vanguard. In 1895, municipal authorities spanned the Chicago River at South Halsted Street with the world's first, modern vertical-lift bridge.

During the middle decades of the 19th century, an occasional vertical-lift span was constructed in Europe and the United States. Although their engineering was often ingenious, the bridges themselves were quite modest, designed mainly for canals and small navigable streams in cases where it was only necessary to lift the spans a few feet to clear traffic in the channels. The modern, long-span, high-rise vertical-lift bridge dates from the last decade of the 19th century. In 1892, Duluth, Minnesota, hosted a design competition for constructing a drawbridge over its harbor entrance on Lake Superior, which comprised a clear channel 250 feet in width. Under the rules of the competition, the successful design would leave the entire width of the canal free to passing vessels, which effectively eliminated traditional, center-pier swing spans.

Most responses to the Duluth competition employed some form of "sliding draw" mechanism, whereby the span moved back and forth on rollers. A striking exception was a design submitted, and later patented, by John Alexander Low Waddell (1854-1938). Waddell was a consulting engineer based in Kansas City, Missouri, who, during the next 40 years, would become one of the best-known bridge engineers in the United States. Waddell proposed to build a vertical lift bridge consisting of a simple truss span 260 feet long so constructed and supported as to allow of being raised vertically to a height of 140 feet above the surface of the canal. The Engineering News, October 27, 1892, reports on the Waddell entry in the design competition...

At each end of the movable span is a tower 170 ft. high, carrying at its top built steel pulleys about 15 ft. in diameter. Over these pulleys steel wire ropes, or chain cables, pass. One end of each cable is attached to the end piers of the trusses, and end to counter-weights which exactly balance the dead weight of the span. The only work left for the operating machinery is, therefore, to overcome the weight due to dirt, water, snow, etc. The power for operating the bridge is supplied by two electric motors placed at mid-span; the upward and downward motion being regulated by racks and pinions communicating with the power by means of steel shafting and spur and miter wheels.

Although the Duluth authorities selected Waddell's design, the War Department vetoed the construction of any drawbridge at the site at that time. Waddell, however, had devised a seemingly practical solution to the drawbridge problem. His vertical-lift navigation and dockage like a swing span, nor did it clutter up span-did not obstruct the shore approaches like a sliding-draw span. A few months after the cancellation of the Duluth project, the City of Chicago commissioned Waddell to modify his original design for a 130-foot span capable of 150-foot clearance over the Chicago River at South Halsted Street. This structure was completed in 1894.

The South Halsted Street Vertical-Lift Bridge remained the only example of its kind for over a decade. In later years, Waddell commented in the Journal of the Western Society of Engineers, May, 1924, that the long delay in constructing another vertical lift to the knavery of those in charge of subsequent bridge projects, who, as he put it, "demanded boodle...a condition with which [I] never did and never will comply." There were other reasons as well. During the period 1895 to 1905, engineers in Chicago and Milwaukee perfected several bascule designs, which were widely believed to be more economical for narrow waterways than Waddell's vertical lift. The new type received early and strong endorsement from the City of Milwaukee, which built 10 bascule spans between 1902 and 1910. It was subsequently adopted as the preferred movable-bridge type by the Wisconsin State Highway Commission, organized in 1911 to improve the state's roads and bridges. But the greatest obstacle to the initial acceptance of the vertical-lift span was the fact that the South Halstead Street Bridge contained certain mechanical flaws, which gave it the reputation for heavy first cost and maintenance and expensive operation.

In 1907, Waddell formed a partnership with John Lyle Harrington (1868-1942), a skilled civil and mechanical engineer who was largely responsible for reworking Waddell's invention into a rational, well-integrated design. In its essential form and dynamics, the "Waddell and Harrington version" remained true to the original 1892 design. Before the partnership dissolved in 1914, Waddell and Harrington designed about 30 vertical-lift spans for highway and railroad crossings. After they parted company, both men continued to work in the field, and Harrington's new office, Harrington, Howard, and Ash, became particularly well known, as was its successor, Ash, Howard, Needles and Tammen. Six vertical-lift highway bridges were constructed in Minnesota and Wisconsin before World War II. At least 5 were designed by Waddell and Harrington or successor firms. All were of the standard Waddell and Harrington type. The 1931 Stillwater Bridge was the last of this cohort to be completed. Its predecessor at the site was a timber, pontoon, Swing Bridge built in 1910. Owned and maintained by the City of Stillwater, the bridge was taken over by the Minnesota Department of Highways in 1925. By that time, the structure was fast deteriorating so as to be a source of apprehension for the safety of the loads it is obliged to carry. When the bridge was closed to heavy traffic in 1928, the Minnesota Department of Highways prepared preliminary plans for its replacement. These plans called for a series of fixed concrete-slab and steel-truss spans, which were to be designed by the Minnesota highway agency itself, and a single vertical-lift span, which was to be the responsibility of an engineering firm specializing in such work. In November, 1929, a design contract for $3,150 was awarded, on a competitive basis, to Ash, Howard, Needles and Tammen of Kansas City, Missouri. Construction on the bridge proper began the following summer, with the Minneapolis firm of Peppard and Fulton serving as general contractor and the American Bridge Company (Minneapolis and Gary plants) serving as fabricator. The project was completed in August, 1931, for a total cost of $460,174, shared on an approximately 50-50 basis by the states of Minnesota and Wisconsin.

At the time of the bridge's completion, the St. Croix River was only lightly used as a navigable waterway. Since most of the traffic was small craft, there was little occasion to operate the lift span, as the Minnesota Department of Highways noted in a 1938 letter, "for several years not a single request for its opening was received." Although the bridge was far more intensely involved in highway traffic, it was in the role of maintaining, rather than initiating, patterns of transportation, which, in fact, were already well established by the 1930s. The bridge does have significance, however, as a rare type of engineering construction. Only six vertical-lift highway bridges were built in Minnesota and Wisconsin prior to World War II, and the Stillwater Bridge is one of three that still survives.

Decorative Character of Modern Plastic Floor Coverings

Thermoplastics are artificial compounds which at certain processing temperatures may be shaped as often as required. The basic substance, polyvinyl chloride, is a tasteless and odourless powder. Through the addition of softeners in the finishing process the flexible, break-proof plastic material is obtained.

With “Pegulan” the completely homogenous floor covering results from the fusion of a number of calendared plastic folia. The material is built up in layers, and by virtue of its practically indestructible surface offers great resistance to wear and tear. Testimonials from several scientific institutes confirm the excellent material qualities of the covering.

Long life, decorative effect, and simple and inexpensive maintenance are the qualities expected from a floor covering. This material meets these demands to a high degree, while the range of colours and the qualities of the material are eminently suited to contemporary interior decorative art.

Well chosen tints in the home should help to promote comfort, good temper and efficiency. The many possible combinations of surface which present themselves allow of the achievement of a well balanced effect even when an arrangement of strong tints is chosen.

This plastic floor covering is available in length approximately 55 and 60 in. (140 and 150 cm.) wide, and in tiles approximately 11½ and 13½ in. (29 and 34 cm.) square. There are many tasteful shades.

The covering, by virtue of its nonporous surface is readily kept clean and meets all the demands of modern hygiene. It is ready for use as soon as it is laid. The high durability of the durelastic p.v.c. material is particularly valuable where heavy wear is anticipated.

In addition, this floor covering is heat insulating, noiseless, elastic, slip proof and light- and flame-resistant. It resists alkalis, acids, oils and fats. It is easily cared for and kept clean, a small amount of polish and a dry mop being all that is needed to impart a shine.

Construction Fire Safety

by Mat Chibbaro, P.E.

Buildings of all types, while under construction, renovation or demolition, are both more susceptible to fire and at greater risk of the effects of fire. A wide variety of ignition sources increase the likelihood of fires starting. Concentrations of combustible materials, incomplete compartmentation and other passive systems, and unfinished fire protection systems allow fire to spread unimpeded. Wind conditions can increase the rapidity of fire spread.

This places at greater risk the workers occupying such buildings and the emergency responders that may be called upon to operate within or near them. Accident statistics and reports tell a tale of many construction workers being killed or maimed over the years by fires and explosions. In May 2008, 14 employees were injured in a natural gas explosion in a hotel under construction in California.

In 2007, two fire-fighters were killed at a fire incident during the demolition of the Deutsche Bank Building in New York City.

Typically, building and fire codes, such as those promulgated by the National Fire Protection Association (NFPA) and the International Code Council (ICC), contain comprehensive lists of the provisions that are to be followed during construction. However, being model standards or codes, they tend to focus more on the "what," and give less attention to the "who," "how" and "when" of implementation. This article presents protection and prevention features of different phases in construction, and discusses ways that the fire protection engineering profession may contribute to efficient and effective implementation of these features.

Building Alliances

An important concept affecting the efficiency of a project is the creation of lines of communication between the various stakeholders.

First, a fire protection engineer can serve as a liaison between disciplines. There is a network of fire safety-related interrelationships between structural fire protection; architectural layout; mechanical, HVACR and plumbing systems; fire suppression systems; electrical features; and fire alarm, detection and control systems. The fire protection engineer is in a unique position to understand how these items work together to achieve overall fire safety goals and thereby work to coordinate them.

The fire protection engineer can also consult with the owner on various concepts. One is the plan for partial occupancy if the owner expects to do this in stages. In some cases, the owner or their insurer will desire protection above and beyond what the fire and building codes require.

Two critical alliances that must be built early, and maintained through a project's life, are those that link the design team with both the code authorities and the emergency response organization in the project's jurisdiction. In some cases, this can be done with one alliance - when the code authority has the ability to speak for the responders within the same fire department or fire brigade. Certainly, the two roles are different - code authorities need to do enforcement, while the responders are in need of information for preincident planning.

Early and regular contact with code authorities can establish communication that is vital to efficient incorporation of code requirements, both those that address construction hazards and those that apply to the finished building. Jurisdictions frequently have amendments to the model codes. Both the base codes and local amendments can be interpreted to accommodate a wide array of sites and structures. The earlier the authority's interpretations and expectations can be learned, the more efficiently the design and construction phases can proceed. This, in turn, translates into cost savings for the owner or developer and valuable time saved for all parties.

Emergency responders face significant challenges during a fire situation in any occupied building. They must deal with an extremely dynamic environment, with limited information on the fire, its byproducts and the building occupants. These challenges are compounded in a building under construction because the protection features and systems are constantly changing, as is the building itself. The more information they have at hand when an incident occurs, the better their decision-making can be, especially during a rapidly unfolding situation.

http://www.fpemag.com/articles/article.asp?i=388

Fire Protection during Construction

Fires are rarely sympathetic to any environment and can quickly destroy weeks, if not months of workmanship during a construction project. It is therefore crucially important that some often simple steps are taken to ensure your project takes the necessary precautions to prevent fire.

Keeping the construction area as clear as possible, particularly when left unattended, should be a key consideration on every foreman's list. Reducing the amount of debris and combustible materials both within the build site and around its immediate boundaries can prevent a fire starting from a loose spark. Clearing the site of these materials should be carried out as often as practicable.

Many fires are started within the roof space of a build therefore it is important to prevent such an occurrence as much as possible. Do this by selecting materials that are fire resistant or do not combust such as Class A asphalt shingles, metal, cement or concrete products.

There are some design considerations as well which could be taken into account. For example, smaller panes and double glazed windows are much more effective in preventing the spread of fire from one room or building to another (providing the windows are built to the appropriate government and construction industry standards).

During the build process, be sure to use surface protection products in both the protection of the finished floor, wall or door, but also with consideration to the prevention of fire. There are numerous products on the market but not all are flame retardant. Why take the risk?

Carpet protection is one of the most common forms of surface protection as carpets are often the most easily of damaged finishings during the final stages of a build. This is perhaps one of the most important areas to ensure fire protection because a fire at this stage of a build is likely to destroy much more than just the carpet.

Prevention is always better than cure, no more so than in the avoidance of fire in the construction industry. Make sure this does not happen to your project by following some simple steps and choosing the right protection products.

http://EzineArticles.com/?expert=Heather_McPhearson

Fire alarm system interfaces

For many years, building fire alarm systems have been used to provide interfaces with building systems beyond the HVAC system interfaces. One example of such interfaces involves signals being sent from the fire alarm system to the building’s elevator control equipment to initiate Phase I emergency operations (or “elevator recall,” as it is commonly referred to within the United States) and return elevators to a designated level for occupant safety and to ensure elevator availability for emergency responders. Another example of fire alarm system integration is where the fire alarm system sends signals to a building’s security system to disable electronic locking devices in the means of egress pathway where such locks are permitted during nonemergency times to restrict the travel of occupants within a building.

Fire alarm systems have been successfully interfaced with other building systems to improve the overall level of safety in large assembly occupancy spaces, such as theatres and large entertainment facilities. In these buildings, it can be difficult for a fire alarm system to draw the attention of an otherwise-occupied person in the building. To address this, fire alarm systems are often interfaced to disable both the use of public address systems and the use of light-dimming equipment. Disabling these systems allows the fire alarm system to be heard and provides an adequate level of illumination for safe occupant egress when evacuation of a space becomes necessary.

http://www.csemag.com/home/single-article/integrating-fire-protection-in-building-systems/eafc82d45e.html

Best Economic System: The Criteria

Among others, there are seven criteria in determining the best economic system.

Abundance

There is abundance when the members of the society experienced satisfaction, mass poverty was eliminated, goods and services are sufficient, no problems in food, clothing, shelter, medicine, education and in recreation.

Growth

The quantitative changes in the economy signify economic growth. As earlier mentioned, economic growth is present when the society acquires greater productive capacity which can be used for consumption or investment. For example, increase in terms of the number of buildings, houses, schools, cars, hospitals, factories or machinery made in a given year.

Stability

When inflation and unemployment are absent in that country then we can say that their economic system is the best because this means that their economic condition is stable.

Security

When there is an assurance of not losing their jobs there follows the security.

Efficiency

It occurs when the opportunity cost (the value of the next best opportunity to a good or to some activity) of some specific amounts of goods is at the lowest possible value and when maximum production from given sources and cost is achieved.

Justice and equity

It is clearly seen when there is fair distribution of income and power among the members of the society. These can be proven when there is sufficient opportunity for job seekers and people had improved their social and economic conditions.

Economic freedom

When consumers are free to choose their food, style of house, education, recreation and etc. then we can say that there is economic freedom. Businessmen are free to invest their money; however this freedom is construed not to violate legal and moral values.

http://www.shvoong.com/social-sciences/economics/1744491-best-economic-criteria/#ixzz1WpMZaWgi

Mixed economy

The term “mixed economy” arose in the context of political debate in the United Kingdom in the postwar period, although the set of policies later associated with the term had been advocated from at least the 1930s. Supporters of the mixed economy, including R. H. Tawney, Anthony Crosland and Andrew Shonfield were mostly associated with the British Labour Party, although similar views were expressed by Conservatives including Harold Macmillan.

Critics of the British mixed economy, including Ludwig von Mises and Friedrich von Hayek, argued that what is called a mixed economy is a move toward socialism and increasing the influence of the state.

The term mixed economy is used to describe economic systems which stray from the ideals of either the market, or various planned economies, and “mix” with elements of each other. As most political-economic ideologies are defined in an idealized sense, what is described rarely if ever exists in practice. Most would not consider it unreasonable to label an economy that, while not being a perfect representation, very closely resembles an ideal by applying the rubric that denominates that ideal. However, when a system in question diverges to a significant extent from an idealized economic model or ideology, the task of identifying it can become problematic. Hence, the term “mixed economy” was coined. As it is unlikely that an economy will contain a perfectly even mix, mixed economies are usually noted as being skewed towards either private ownership or public ownership, toward capitalism or socialism, or toward a market economy or command economy in varying degrees.

There is not a consensus on which economies are capitalist, socialist, or mixed. It may be argued that the historical tendency of power holders in all times and places to limit the activities of market actors combined with the natural impossibility of monitoring and constraining all market actors has resulted in the fact that, as we understand a “mixed economy” being a combination of governmental enterprise and free-enterprise, nearly every economy to develop in human history meets this definition.

The elements of a mixed economy typically include a variety of freedoms:

• to possess means of production (farms, factories, stores, etc.)

• to participate in managerial decisions (cooperative and participatory economics)

• to travel (needed to transport all the items in commerce, to make deals in person, for workers and owners to go to where needed)

• to buy (items for personal use, for resale; buy whole enterprises to make the organization that creates wealth a form of wealth itself)

• to sell (same as buy)

• to hire (to create organizations that create wealth)

• to fire (to maintain organizations that create wealth)

• to organize (private enterprise for profit, labour unions, workers' and professional associations, non-profit groups, religions, etc.)

• to communicate (free speech, newspapers, books, advertisements, make deals, create business partners, create markets)

• to protest peacefully (marches, petitions, sue the government, make laws friendly to profit making and workers alike, remove pointless inefficiencies to maximize wealth creation)

What is Construction Management?

Construction Management is a professional management practice consisting of an array of services applied to construction projects and programs through the planning, design, construction and post construction phases for the purpose of achieving project objectives including the management of quality, cost, time and scope.

Construction Management is a discipline and management system specifically created to promote the successful execution of capital projects for owners. These projects can be highly complex. Few owners maintain the staff resources necessary to pay close, continuing attention to every detail--yet these details can “make or break” a project.

A professional CM can augment the owner's staff with pre-planning, design, construction, engineering and management expertise that can assure the best possible project outcome no matter what type of project delivery method used.

“Agency” CM is a professional service that can be applied to all delivery systems where the CM acts as the owner's principal agent in the management of a construction project or program, where the CM is responsible to the owner for managing the planning, design, construction and post construction phases, or portions thereof. The CM represents the interests of the project in its dealings with other construction professionals, and with other private and public entities.

• Optimum use of available funds

• Control of the scope of the work

• Project scheduling

• Optimum use of design and construction firms' skills and talents

• Avoidance of delays, changes and disputes

• Enhancing project design and construction quality

• Optimum flexibility in contracting and procurement

Comprehensive management of every stage of the project, beginning with the original concept and project definition, yields the greatest possible benefit to owners from Construction Management.

“At-risk” CM is a delivery method which entails a commitment by the construction manager to deliver the project within a Guaranteed Maximum Price (GMP). The construction manager acts as consultant to the owner in the development and design phases, but as the equivalent of a general contractor during the construction phase. When a construction manager is bound to a GMP, the most fundamental character of the relationship is changed. In addition to acting in the owner's interest, the construction manager also protects him/herself.

http://cmaanet.org/construction-management

Construction Managers: Nature of the Work

Construction managers plan, direct, coordinate, and budget a wide variety of construction projects, including the building of all types of residential, commercial, and industrial structures, roads, bridges, wastewater treatment plants, and schools and hospitals. Construction managers may supervise an entire project or just part of one. They schedule and coordinate all design and construction processes, including the selection, hiring, and oversight of specialty trade contractors, such as carpentry, plumbing, or electrical, but they usually do not do any actual construction of the structure.

Construction managers are salaried or self-employed managers who oversee construction supervisors and personnel. They are often called project managers, constructors, construction superintendents, project engineers, construction supervisors, or general contractors. Construction managers may be owners or salaried employees of a construction management or contracting firm, or they may work under contract or as a salaried employee of the property owner, developer, or contracting firm managing the construction project.

These managers coordinate and supervise the construction process from the conceptual development stage through final construction, making sure that the project gets completed on time and within budget. They often work with owners, engineers, architects, and others who are involved in the process. Given the designs for buildings, roads, bridges, or other projects, construction managers supervise the planning, scheduling, and implementation of those designs.

Large construction projects, such as an office building or an industrial complex, are often too complicated for one person to manage. Accordingly, these projects are divided into various segments: site preparation, including clearing and excavation of the land, installing sewage systems, and landscaping and road construction; building construction, including laying foundations and erecting the structural framework, floors, walls, and roofs; and building systems, including protecting against fire and installing electrical, plumbing, air-conditioning, and heating systems. Construction managers may be in charge of one or several of these activities.

Construction managers determine the best way to get materials to the building site and the most cost-effective plan and schedule for completing the project. They divide all required construction site activities into logical steps, estimating and budgeting the time required to meet established deadlines. Doing this may require sophisticated scheduling and cost-estimating techniques using computers with specialized software.

Construction managers also manage the selection of general contractors and trade contractors to complete specific phases of the project—which could include everything from structural metalworking and plumbing, to painting, to installing electricity and carpeting. Construction managers determine the labour requirements of the project and, in some cases, supervise or monitor the hiring and dismissal of workers. They oversee the performance of all trade contractors and are responsible for ensuring that all work is completed on schedule.

Construction managers direct and monitor the progress of construction activities, occasionally through construction supervisors or other construction managers. They are responsible for obtaining all necessary permits and licenses and, depending upon the contractual arrangements, for directing or monitoring compliance with building and safety codes, other regulations, and requirements set by the project's insurers. They also oversee the delivery and use of materials, tools, and equipment; worker safety and productivity; and the quality of the construction.

http://www.bls.gov/oco/ocos005.htm

The Functions of an Executive

Each company has its business structure. An organization has a number of positions and some people have more authority than others.

Top Management of a corporation consists of the board of directors and the executive officers. The board of directors determines the basic company policies and appoints the executive officers. These officers include a chairman of the board, a president and a number of vice presidents. They are responsible for carrying out the decisions of the board of directors and the stockholders. The executive officers select the managers (or the heads) of the various departments of the corporation. The Managing Director (sometimes called the Chief Executive or the President in Russia and the USA) is the head of the company.

The number of departments in a corporation depends on the size of the company and on the nature of the goods and services that it provides. A corporation with many employees may need a personnel department. A manufacturing firm may need a research department to study ways of developing new products. Most corporations have departments that handle three basic business activities - production, finance and marketing.

The Production department consists of several divisions: Production, Packaging, Distribution, Quality and Maintenance.

The Marketing department plans how to sell new products and may include Advertising division.

The Finance department connects with customer accounts, wages and salaries, financial services, taxation, investment and cash management.

What Are the Duties of a Public Relations Officer?

Public relations officers are responsible for how companies are represented in the media. Public relations officers are primarily spokespeople for the organization to the media. They are also responsible for writing and creating press kits, organizing press tours, and monitoring the media and Internet forums to learn what is communicated about the organization. Public relations officers are also responsible for creating a media strategy and ensuring that it is followed. They are responsible for both internal and external public relations – communication within the organization and to the public.

Spokesperson

A public relations officer handles media requests, answering questions that are posed by the media, including reporters who represent radio, television, Internet publications, newspapers, and magazines. Members of the media contact public relations officers to verify information or get comments for news stories about a company or an organization. The public relations officer should be the primary contact for the media. Public Relations Officers may work for nonprofit organizations or businesses.

Write

Public relations officers write press releases, newsletters, or other internal and external communication. Internal publications include newsletters, memos, and email notices for the company's staff. External communications are press releases submitted to reporters and publications that are meant for the public to read or see. The public relations officer publicizes positive news and events related to the company. He serves as the lead writer, writing the press releases and distributing them to the media.

Monitor News

Public relations officers monitor the news media for news that is related to the organization to find out how the organization is portrayed by the media. The officer should understand customer and client needs and how the media -- in print, on television, on the radio, and online -- present these needs.

Develop a Public Relations Strategy

Public relations officers must develop a plan to brand the company in the media. They must develop contacts in the media and use the company's mission statement as a guide for marketing. The plan helps the organization establish or maintain recognition in the public eye.

Organize Media Events

The public relations officer may organize press trips, press conferences, or in-house tours for the media. To do this she may contact stakeholders and venues, and make arrangements to show and present information to the media that is representative of the company's message.

http://www.ehow.com

social structure

History of the concept of social structure

The concept of social structure has a long history in the social sciences, going back for example to the functionalism of figures such as Herbert Spencer, the class structure analysis of Karl Marx, or the work of 19th century German sociologist Georg Simmel on social structure as abstract patterns underlying human interaction.

The notion of social structure has been extensively developed in the twentieth century, with key contributions from structuralist perspectives drawing on the structuralism of Levi-Strauss, Feminist or Marxist perspectives, from functionalist perspectives such as those developed by Talcott Parsons and his followers, or from a variety of analytic perspectives (see Blau 1975, Lopez and Scott 2000).

The notion of social structure is intimately related to a variety of central topics in social science, including the relation of structure and agency.

Definitions and concepts of social structure

As noted above, social structure has been identified as

(i) the relationship of definite entities or groups to each other,

(ii) as enduring patterns of behaviour by participants in a social system in relation to each other, and

(iii) as institutionalised norms or cognitive frameworks that structure the actions of actors in the social system.

Lopez and Scott (2000) distinguish between institutional structure and relational structure, where in the former:

. . . social structure is seen as comprising those cultural or normative patterns that define the expectations of agents hold about each other's behaviour and that organize their enduring relations with each other.

whereas in the latter:

. . . social structure is seen as comprising the relationships themselves, understood as patterns of causal interconnection and interdependence among agents and their actions, as well as the positions that they occupy.

Social structure can also be divided into microstructure and macrostructure. Microstructure is the pattern of relations between most basic elements of social life, that cannot be further divided and have no social structure of their own (for example, pattern of relations between individuals in a group composed of individuals – where individuals have no social structure, or a structure of organizations as a pattern of relations between social positions or social roles, where those positions and roles have no structure by themselves). Macrostructure is thus a kind of 'second level' structure, a pattern of relations between objects that have their own structure (for example, a political social structure between political parties, as political parties have their own social structure). Some special types of social structures that modern sociologist differentiate are relation structures (in family or larger family-like clan structures), communication structures (how information is passed in organizations) and sociometric structures (structures of sympathy, antipathy and indifference in organisations – this was studied by Jacob L. Moreno).

Sociologists also distinguish between:

• normative structure — pattern of relations in given structure (organisation) between norms and modes of operations of people of varying social positions

• ideal structure — pattern of relations between beliefs and views of people of varying social positions

• interest structure — pattern of relations between goals and desires of people of varying social positions

• interaction structure — forms of communications of people of varying social positions

Origins and evolution of social structure

Some believe that social structure is naturally developed. It may be caused by larger system needs, such as the need for labour, management, professional and military classes, or by conflicts between groups, such as competition among political parties or among elites and masses. Others believe that this structuring is not a result of natural processes, but is socially constructed. It may be created by the power of elites who seek to retain their power, or by economic systems that place emphasis upon competition or cooperation.

The most thorough account of the evolution of social structure is perhaps provided by structure and agency accounts that allow for a sophisticated analysis of the co-evolution of social structure and human agency, where socialised agents with a degree of autonomy take action in social systems where their action is on the one hand mediated by existing institutional structure and expectations but may, on the other hand, influence or transform that institutional structure.

The notion of social structure may mask systematic biases

Some argue that men and women who have otherwise equal qualifications receive different treatment in the workplace because of their gender. Others note that individuals are sometimes viewed as having different essential qualities based on their race and ethnicity, regardless of their individual qualities. When examined, these social distinctions are often considered stereotypes based on prejudice. However, these social distinctions often go unexamined because they appear to be the result of social structures rather than prejudice.

http://english.turkcebilgi.com/Social+system

Solar Air Heating Systems

MatrixAir™ Transpired Solar Air Collector

Designed for new construction or retrofits this patent-pending, unglazed transpired solar air heating collector resembles conventional exterior metal siding.   Recommended for solar air heating systems with total fresh air flow needs of at least 3000 CFM, MatrixAir™ TR (Transpired) Solar Air Heating collectors come in a wide variety of cladding styles and colours and are practically unlimited their size or output.  MatrixAir™ “TR” series transpired solar air collectors require the use of an air outlet below the mid point of the collector.

MatrixAir™ Backpass Solar Air Collector

Ideally suited for new construction with collector heights ranging from 12 – 24 ft, this backpass solar air collector performs to within 99% of the performance of our transpired solar air heating collector thanks to our unique, modular, patent-pending design. The MatrixAir™ BP (Backpass) Solar Air Heating is characterized by its horizontal plenum located along the top of the collector or roof mounted behind the vertical cladding to facilitate integration with ceiling or roof mounted HVAC and a wide range of CFM requirements. Note: Backpass (BP) solar air heating systems are well suited to upper wall-mounted fresh air inlets prescribed by ASHRAE 62.1

MatrixAir™ Delta Roof Mounted Modular Solar Air Collector

Our roof mounted modular solar air heating collector is the ideal solution for those circumstances where no wall area is suitable for a façade mounted collector due to obstructions, glazing, bylaws or wall orientation.  Incorporating a flat, transpired absorber and built-in air plenum this solar air heating modular system optimizes the solar heated air flow through each solar collector for maximum output.  The individual MatrixAir™ Delta Solar Air Heating 250 CFM modules may be connected in a combination of series and parallel configurations to address a wide variety of roof layouts or CFM requirements.

http://www.matrixenergy.ca/solar-air-heating/products.html

Cast Stone Elements - Group 1

MeltonStone™ Cast Stone Banding & Watertables

Enhance the beauty of your masonry facade by incorporating MeltonStone Cast Stone Banding into your design. MeltonStone Cast Stone Banding can add distinction and elegance to your buildings’ design by introducing contrast between the colour and texture of your brick, stone or other masonry. The utilization of horizontal or vertical rows of MeltonStone Banding throughout the brick veneer allows the design professional to define wall sections and spaces, and add depth, colour and distinction to the design. By combining economical MeltonStone flush and profiled banding, water table, medallions and other MeltonStone Architectural Elements, the design professional can add their own unique design imprint to their building design at amazingly affordable prices. You can select from any of our standard MeltonStone Banding profiles, or have an economically priced custom detail made from your drawings.

MeltonStone™ Custom Cast Stone Elements

Let your imagination run free. Medallions, signage, fountains, fireplaces or pilaster capitals and essentially anything you can imagine can be cast in durable MeltonStone Cast Stone. If you have seen it anywhere in architecture, we can create it for you in durable and beautiful MeltonStone Cast Stone.

MeltonStone™ Cast Stone Entry Systems

Let your entry system make a dramatic statement about the quality of your building project with MeltonStone Cast Stone Entry Features. Built with quality for lasting beauty, MeltonStone Cast Stone entry features are offered in your selection of stone colours to enhance the beauty of your building project. From a simple arch with keystone to a complete façade with MeltonStone cast stone architectural columns, Melton Classics cast stone entry features enhance the beauty and value of your building.

MeltonStone™ Cast Stone Pavers

MeltonStone™ cast stone paving stones add beauty and elegance to plazas, walkways, patios, porches, pool decks and walkways. Available in a wide range of sizes, colors and shapes, our cast stone paving stones can be incorporated into a wide array of patterns to create dramatic architectural designs for your project. MeltonStone paving stones can be arranged in multicoloured mosaics with bands and arches for a dramatic geometric look to add interest and flair to any courtyard. The only limit to what you can create with MeltonStone™ paving stones is your imagination.

MeltonStone™ Cast Stone Pier Caps & Finials

Melton Classics offers pier caps and finials to crown the tops of piers to enhance any design. Whether your design calls for an enhancement to an estate entry gate, an addition to an elegant balustrade pier, or a beautiful top for the piers on a masonry wall, Melton Classics can fulfil any pier cap or finial need. Whether your design calls for an urn or planter or a classic ball or simple peaked pier cap, Melton Classics has a pier cap and finial for your design needs. We also can economically create a custom pier cap or finial to your unique specifications.

Cast Stone Elements - Group 2

MeltonStone™ Cast Stone Quoins

Historically, quoins were used to tie the corner of a structure together while creating a contrasting feature to frame the structure visually. Melton Classics has a wide variety of classic quoin designs available in numerous sizes and natural stone colours to enhance the architectural presence of your project. Available with square or chamfered edges in a thickness of 3 5/8" or more, our quoins are ideal to frame the corners of any brick or stone structure. Our quoins are also available for installation in a staggered or linear layout to allow design flexibility. MeltonStone™ quoins can be manufactured with attachment slots on top and bottom or provided with threaded inserts for ease of installation.

MeltonStone™ Cast Stone Stair Treads and Risers

MeltonStone™ cast stone stair treads and risers are as beautiful as they are functional, and are available in several stone colours. Our treads and risers are designed to work together to compliment our MeltonStone™ pavers and balustrade products in creating a coordinated architectural design for your porch or stairway. Treads are available with your choice of bull nosed, ogee or chamfered leading edges to accommodate any architectural design. Treads and risers are available in a wide array of sizes for straight or spiral stairways and may be ordered with or without returns.

MeltonStone™ Cast Stone Veneers

Also known as Ashlar Block, cast stone veneer has been used in building construction for decades to provide contrasting colour and texture to fine masonry architecture. Melton Classics offers the design professional a wide array of colours, textures and shapes for their cast stone ashlar block or cast stone veneer needs. From an arched wall feature with a balustrade above to the entire base of a large building, MeltonStone cast stone veneer adds beauty and elegance to your building design. MeltonStone veneer is available in several textures to enhance your design. Our standard sugar cube smooth textured MeltonStone veneer is offered in a variety of sizes and shapes with flat or chamfered edges. For the rustic look of stone we also offer split face or rock faced ashlar blocks or veneer. We also offer several Standard Colours and Profiles, or a custom colour of your choice to contrast or coordinate as desired with your stone or other masonry.

MeltonStone™ Cast Stone Wall Coping

In addition to its functional use as moisture protection for exterior masonry, parapet and landscape walls, MeltonStone Cast Stone wall coping, pier caps and finials are utilized by appearance conscious design professionals to add elegance, contrast, and a finished appearance to their masonry wall designs. Available in single and double sloped styles, or in your own custom design, MeltonStone Wall Coping is the ideal economical wall cap for your exterior wall designs. Our wall coping can be coordinated with a myriad of MeltonStone cast stone Pier Caps and Finials to add flair, and a unique appointment to your wall designs. Whether you want an urn finial, pineapple finial or a classic ball finial, Melton Classics can economically enhance the look of your masonry piers with one of our many beautiful cast stone finials to meet your design requirements.

MeltonStone™ Cast Stone Window Features

Melton Classics offers a wide array of cast stone window pediments, jack arches, keystones, casings, panels and sills to allow you to embellish the window openings for your project. The combination of contrasting MeltonStone Cast Stone window features with brick or stone veneer adds contrasting texture and colour to the facade of fine architecture.

Water Resources Management

Challenges

Water is essential for socio-economic development and for maintaining healthy ecosystems. Properly managed water resources are a critical component of growth, poverty reduction and equity. The livelihoods of the poorest are critically associated with access to water services.

With higher rates of urbanization, increasing demand for drinking water will put stress on existing water sources. Feeding a planet of 8 billion by 2030 will require producing more food with less water and through improved water efficiency in agriculture. Energy demand will more than double in poor and emerging economies in the next 25 years and hydropower will need to be a key contributor to clean energy production. Floods and droughts will continue to threaten farmer livelihoods and lowland economies. Besides the needs for these human activities we have to ensure that the environmental water flows required maintaining ecosystems are also maintained.

Water Resources Management aims at optimizing the available natural water flows, including surface water and groundwater, to satisfy these competing needs. Adding uncertainty, climate change will increase the complexity of managing water resources. In some parts of the world, there will be more available water but in other parts, including the developing world, there will be less.

The mounting challenges posed by the changing demand for and supply of the resource highlight the importance of water in any development and growth agenda. The ability of developing countries to make more water available for domestic, agricultural, industrial and environmental uses will depend on better management of water resources and more cross-sectoral planning and integration. With water security declining in many parts of the world, strengthening the resiliency of the poorest countries and populations to climate change impacts, becomes crucial, not only to ensure future water supply but also to combat food and energy price volatility.

http://water.worldbank.org/water/topics/water-resources-management

Water distribution

Pecos: Water Tower

A water distribution system is a network of pumps, pipelines, storage tanks, and other appurtenances. It must deliver adequate quantities of water at pressures sufficient for operating plumbing fixtures and fire fighting equipment, yet it must not deliver water at pressures high enough to increase the occurrence of leaks and pipeline breaks. Pressure-regulating valves may be installed to reduce pressure levels in low-lying service areas. More than half the cost of a municipal water supply system is for the distribution network.

Pipelines

The pipeline system of a municipal water distribution network consists of arterial water mains or primary feeders, which convey water from the treatment plant to areas of major water use in the community, and smaller-diameter pipelines called secondary feeders, which tie in to the mains. Usually not less than 150 mm (6 inches) in diameter, these pipelines are placed within the public right-of-way so that service connections can be made for all potential water users. The pipelines are usually arranged in a gridiron pattern that allows water to circulate in interconnected loops; this permits any broken sections of pipe to be isolated for repair without disrupting service to large areas of the community. “Dead-end” patterns may also be used, but they do not permit circulation, and the water they provide is more susceptible to taste and odour problems because of stagnation.

A water distribution pipeline must be able to resist internal and external forces, as well as corrosion. Pipes are placed under stress by internal water pressure, by the weight of the overlying soil, and by vehicles passing above. They may have to withstand water-hammer forces; these occur when valves are closed too rapidly, causing pressure waves to surge through the system. In addition, metal pipes may rust internally if the water supply is corrosive or externally because of corrosive soil conditions.

Materials

Distribution pipes are made of asbestos cement, cast iron, ductile iron, plastic, reinforced concrete, or steel. Although not as strong as iron, asbestos cement, because of its corrosion resistance and ease of installation, is a desirable material for secondary feeders up to 41 cm (16 inches) in diameter. Pipe sections are easily joined with a coupling sleeve and rubber-ring gasket. Cast iron has an excellent record of service, with many installations still functioning after 100 years. Ductile iron, a stronger and more elastic type of cast iron, is used in newer installations. Iron pipes are provided in diameters up to 122 cm (48 inches) and are usually coated to prevent corrosion. Underground sections are connected with bell-and-spigot joints, the spigot end of one pipe section being pushed into the bell end of an adjacent section. A rubber-ring gasket in the bell end is compressed when the two sections are joined, creating a watertight, flexible connection. Flanged and bolted joints are used for aboveground installations.

Plastic pipes are available in diameters up to 61 cm (24 inches). They are lightweight, easily installed, and corrosion-resistant, and their smoothness provides good hydraulic characteristics. Plastic pipes are connected either by a bell-and-spigot compression-type joint or by threaded screw couplings.

Precast reinforced concrete pipe sections up to 366 cm (12 feet) in diameter are used for arterial mains. Reinforced concrete pipes are strong and durable. They are joined using a bell-and-spigot-type connection that is sealed with cement mortar. Steel pipe is sometimes used for arterial mains in aboveground installations. It is very strong and lighter than concrete pipe, but it must be protected against corrosion with lining of the interior and with painting and wrapping of the exterior. Sections of steel pipe are joined by welding or with mechanical coupling devices.

http://www.britannica.com/EBchecked/topic/637296/water-supply-system

Road Maintenance

Proper road maintenance contributes to reliable transport at reduced cost, as there is a direct link between road condition and vehicle operating costs (VOC). An improperly maintained road can also represent an increased safety hazard to the user, leading to more accidents, with their associated human and property costs. In general, road maintenance activities can be broken into four categories:

• Routine works. These are works that are undertaken each year that are funded from the recurrent budget. Activities can be grouped into cyclic and reactive works types. Cyclic works are those undertaken where the maintenance standard indicates the frequency at which activities should be undertaken. Examples are verge cutting and culvert cleaning, both of which are dependent on environmental effects rather than on traffic levels. Reactive works are those where intervention levels, defined in the maintenance standard, are used to determine when maintenance is needed. An example is patching, which is carried out in response to the appearance of cracks or pot-holes.

• Periodic works. These include activities undertaken at intervals of several years to preserve the structural integrity of the road, or to enable the road to carry increased axle loadings. The category normally excludes those works that change the geometry of a road by widening or realignment. Works can be grouped into the works types of preventive, resurfacing, overlay and pavement reconstruction. Examples are resealing and overlay works, which are carried out in response to measured deterioration in road conditions. Periodic works are expected at regular, but relatively long, intervals. As such, they can be budgeted for on a regular basis and can be included in the recurrent budget. However, many countries consider these activities as discrete projects and fund them from the capital budget.

• Special works. These are activities whose need cannot be estimated with any certainty in advance. The activities include emergency works to repair landslides and washouts that result in the road being cut or made impassable. Winter maintenance works of snow removal or salting are also included under this heading. A contingency allowance is normally included within the recurrent budget to fund these works, although separate special contingency funds may also be provided.

• Development. These are construction works that are identified as part of the national development planning activity. As such, they are funded from the capital budget. Examples are the construction of by-passes, or the paving of unpaved roads in villages.

Monitoring, Implementation and Evaluation of Roads

Construction, especially with respect to the contracting and bidding for civil works, requires the effective evaluation and supervision of contractors and their bids. Without this ability at tender, marginal or unacceptable bidders can distort the bidding process by excessive underbidding for contracts or future inability to complete.

At the point of construction, poor contractors can raise owner’s supervision and staffing costs substantially. Management of the road network requires different information, at different levels of the decision-making process, for example, for planning, for programming, for design, and for implementation. The data to be collected by an inspection system, and where, and how it should be collected, depend largely on the use of the data. Senior managers in road administrations may also be required to make decisions about the choice of computerised road management systems that are to be implemented within their organizations. The consequences of such decisions can be very costly, not only in terms of the cost of initial system procurement, but also because of the on-going costs of system management and data collection. The implementation of systems can have far-reaching effects on all aspects of the operation of the road administration. Hence, it is important that managers are aware of the need for an effective approach to system implementation, and of the pitfalls of making inappropriate decisions in this area.

http://www.worldbank.org/transport/roads/con&main.htm#implementation

How to Spread Gravel on a Road

Gravel provides excellent water drainage

and is an inexpensive road surfacing option

Gravel is a common and inexpensive road surface that is easy to create and maintain. It is the preferred surface for roads in high-moisture locations where drainage is an issue. If a gravel road is properly prepared and spread, it can last for years or even decades with minimal maintenance.

Instructions

Things You'll Need

• Geotextile fabric

• No. 3 gravel

• Tamping machine

• No. 57 gravel

• No. 21-A gravel

1 Remove the topsoil as well as any organic debris from the road. Topsoil is too soft to effectively hold the gravel in place, and can turn your gravel road into a muddy mess.

2 Create a "crown" in the base of the road. A crown is simply a slight slope from the center of the road out toward the sides. It ensures that water runs off and away from the road rather than gathering and pooling in the middle.

3 Lay down a layer of geotextile fabric. This fabric will keep the substrate from muddying the gravel and will dramatically increase the longevity of your road.

4 Distribute a 4-inch layer of No. 3 gravel across the entire road. This gravel, approximately the size of baseballs, will form the rigid base of the road. Tamp the gravel down with a tamping machine.

5 Add a 4-inch layer of No. 57 gravel on top of the No. 3 gravel. No. 57 gravel is about the size of golf balls. Tamp the second layer down with a tamping machine. Take care to preserve the road's slightly crowned shape.

6 Add a 4-inch layer of No. 21-A gravel to the road. This gravel is marble-sized and contains gravel dust. Tamp the final layer of gravel down, securing it in place.

How to Spread Gravel on a Road | eHow.com http://www.ehow.com/how_8661512_spread-gravel-road.html#ixzz1Wv6RRA6t

Front Loader – Construction Equipment

by Er. Ankush

Also known as a front end loader, bucket loader, scoop loader, or shovel, the front loader is a type of tractor that is normally wheeled and uses a wide square tilting bucket on the end of movable arms to lift and move material around. The loader assembly may be a removable attachment or permanently mounted on the vehicle. Often times, the bucket can be replaced with other devices or tools, such as forks or a hydraulically operated bucket.

Larger style front loaders, such as the Caterpillar 950G or the Volvo L120E, normally have only a front bucket and are known as front loaders, where the small front loaders are often times equipped with a small backhoe as well and called backhoe loaders or loader backhoes. Loaders are primarily used for loading materials into trucks, laying pipe, clearing rubble, and also digging. Loaders aren’t the most efficient machines for digging, as they can’t dig very deep below the level of their wheels, like the backhoe can.

The deep bucket on the front loader can normally store around 3 – 6 cubic meters of dirt, as the bucket capacity of the loader is much bigger than the bucket capacity of a backhoe loader. Loaders aren’t classified as excavating machinery, as their primary purpose is other than moving dirt. In construction areas, mainly when fixing roads in the middle of the city, front loaders are used to transport building materials such as pipe, bricks, metal bars, and digging tools. Front loaders are also very useful for snow removal as well, as you can use their bucket or as a snow plough. They can clear snow from the streets and highways, even parking lots. They will sometimes load the snow into dump trucks which will then haul it away.

Unlike the bulldozer, most loaders are wheeled and not tracked. The wheels will provide better mobility and speed and won’t damage paved roads near as much as tracks, although this will come at the cost of reduced traction. Unlike backhoes or tractors fitted with a steel bucket, large loaders don’t use automotive steering mechanisms, as they instead steer by a hydraulically actuated pivot point set exactly between the front and rear axles. This is known as articulated steering and will allow the front axle to be solid, therefore allowing it to carry a heavier weight.

Articulated steering will also give a reduced turn in radius for a given wheelbase. With the front wheels and attachment rotating on the same axis, the operator is able to steer his load in an arc after positioning the machine, which can come in quite handy. The problem is that when the machine is twisted to one side and a heavy load is lifted high in the air, it has a bigger risk of turning over.

http://www.engineeringcivil.com/theory/construction-equipments/

Various Types Of Cranes

by Er. Vikrant

A crane is a tower or derrick that is equipped with cables and pulleys that are used to lift and lower material. They are commonly used in the construction industry and in the manufacturing of heavy equipment. Cranes for construction are normally temporary structures, either fixed to the ground or mounted on a purpose built vehicle.

They can either be controlled from an operator in a cab that travels along with the crane, by a push button pendant control station, or by radio type controls. The crane operator is ultimately responsible for the safety of the crews and the crane.

Mobile Cranes

The most basic type of crane consists of a steel truss or telescopic boom mounted on a mobile platform, which could be a rail, wheeled, or even on a cat truck. The boom is hinged at the bottom and can be either raised or lowered by cables or hydraulic cylinders.

Telescopic Crane

This type of crane offers a boom that consists of a number of tubes fitted one inside of the other. A hydraulic mechanism extends or retracts the tubes to increase or decrease the length of the boom.

Tower Crane

The tower crane is a modern form of a balance crane. When fixed to the ground, tower cranes will often give the best combination of height and lifting capacity and are also used when constructing tall buildings.

Truck Mounted Crane

Cranes mounted on a rubber tire truck will provide great mobility. Outriggers that extend vertically or horizontally are used to level and stabilize the crane during hoisting.

Rough Terrain Crane

A crane that is mounted on an undercarriage with four rubber tires, designed for operations off road. The outriggers extend vertically and horizontally to level and stabilize the crane when hoisting. These types of cranes are single engine machines where the same engine is used for powering the undercarriage as it is for powering the crane. In these types of cranes, the engine is normally mounted in the undercarriage rather than in the upper portion.

Loader Crane

A loader crane is a hydraulically powered articulated arm fitted to a trailer, used to load equipment onto a trailer. The numerous sections can be folded into a small space when the crane isn’t in use.

Overhead Crane

Also referred to as a suspended crane, this type is normally used in a factory, with some of them being able to lift very heavy loads. The hoist is set on a trolley which will move in one direction along one or two beams, which move at angles to that direction along elevated or ground level tracks, often mounted along the side of an assembly area.

In the excavation world, cranes are used to move equipment or machinery. Cranes can quickly and easily move machinery into trenches or down steep hills, or even pipe. There are many types of cranes available, serving everything from excavation to road work.

Cranes are also beneficial to building bridges or construction. For many years, cranes have proven to be an asset to the industry of construction and excavating. Crane operators make really good money, no matter what type of crane they are operating.

http://www.engineeringcivil.com/theory/construction-equipments/

Compact Excavator

by Er. Vikrant

The compact hydraulic excavator can be a tracked or wheeled vehicle with an approximate operating weight of 13,300 pounds. Normally, it includes a standard backfill blade and features an independent boom swing. The compact hydraulic excavator is also known as a mini excavator.

A compact hydraulic excavator is different from other types of heavy machinery in the sense that all movement and functions of the machine are accomplished through the transfer of hydraulic fluid. The work group and blade are activated by hydraulic fluid acting upon hydraulic cylinders. The rotation and travel functions are also activated by hydraulic fluid powering hydraulic motors.

Most types of compact hydraulic excavators have three assemblies – house, undercarriage, and the work group.

House The house structure contains the compartment for the operator, engine compartment, hydraulic pump and also the distribution components. The house structure is attached to the top of the undercarriage via swing bearing. Along with the work group, them house is able to rotate upon the undercarriage without limit due to a hydraulic distribution valve that supplies oil to the undercarriage components.

Undercarriage The undercarriage of compact excavators consists of rubber or steel tracks, drive sprockets, rollers, idlers, and associated components and structures. The undercarriage is also home to the house structure and the work group.

Work group

The work group consists of the boom, dipper or arm, and attachment. It is connected to the front of the house structure via a swinging frame that allows the work group to be hydraulically pivoted left or right in order to achieve offset digging for trenching parallel with the tracks.

Independent boom swing

The purpose of the boom swing is for offset digging around obstacles or along foundations, walls, and forms. Another use is for cycling in areas that are too narrow for cab rotation. Another major advantage of the compact excavator is the independent boom swing.

Backfill blade

The backfill blade on compact excavators is used for grading, levelling, backfilling, trenching, and general dozer work. The blade can also be used to increase the dumping height and digging depth depending on its position in relation to the workgroup.

The most common place you’ll find compact excavators is in residential dwellings. When digging phone lines or other things, these pieces of equipment are very common for getting between houses. Due to their small size, they can fit almost anywhere. Over the years, the capabilities for compact excavators have expanded far beyond the tasks of excavation. With hydraulic powered attachments such as breakers, clamps, compactors and augers, the compact excavator is used with many other applications and serves as an effective attachment tool as well. Serving many purposes, the compact excavator is a great addition to any job that requires the use of machinery.

http://www.engineeringcivil.com/theory/construction-equipments/

Information Technologies Engineering

Information technology (IT) engineers deal with the design and integration of multiple systems of structured cable and wireless information technologies relating to buildings and building occupants:

• Building systems—HVAC, lighting, daylighting control, energy monitoring, security access, and fire/smoke detection and alarm.

• Telecommunications—voice, data, graphics, and audiovideo.

Several developments which occurred somewhat simultaneously in the early 1980s drove the explosive growth of information technology—the divestiture of the Bell corporate empire, the Internet, the personal computer, user friendly software interfaces, and large capacity investments in telecommunications infrastructure, satellites, and fiber optic cable systems.

The emerging development of building information modeling (BIM) has the potential to integrate the design, fabrication, construction, and O&M databases over the life cycle of the building development.

Description

Integrated Design

Concept of a Security Command Center that integrates

multiple technologies seamlessly into one facility

Such systems as telecommunications, data, building operation controls, audiovisual, and security are commonly introduced as separately operating systems. Integrated building systems now have the capability to use the same structured cable network and enable interoperability across all systems. The IT Engineer designs the structured cable system network that enables the user's technology systems and the building operating systems to function in an integrated manner.

Synergies enabling user comfort and building energy savings can be realized when integrated systems can interact seamlessly, thus benefiting the comfort and business needs of the user and the building owner simultaneously.

This is most easily accomplished when all building stakeholders and members of the design team are brought as early as possible into the integrated design process. The IT Engineer should be involved with design decisions from project start since IT design overlaps and affects building operations systems, vertical and horizontal space utilization, and user/organizational business needs.

Design Objectives

Information systems will affect all design objectives of the complex modern commercial, institutional, or governmental building:

• Accessible for physically challenged user access to telecommunications and security devices

• Cost-Effective for initial construction cost and user life-cycle cost

• Functional/Operational for integrated control of building operational systems and building automated systems (BAS)

• Productive for user health and comfort, and business/organization needs

• Secure/Safe for building security access, surveillance, fire/smoke detection and alarm systems; and user LAN/WAN network security

• Sustainable—Enhance Indoor Environmental Quality; Optimize O&M Practices for high performance optimization of building controls and operational systems

• The design and implementation of wiring and cabling systems has direct impact on aesthetics and preserving historic spaces within the building.

As advanced electronic entertainment systems, home offices, and telecommuting become more prevalent, multi-unit and single-unit residential buildings are being built and marketed to attract the IT-sophisticated residential consumer.

Flexibility

Scalable IT infrastructure will accommodate

future technologies

All organizations must be adaptable to a high rate of change. IT is one of the most rapidly changing aspects of technologically advanced societies across the globe. New devices and technologies for business and personal use are constantly being brought to market. As new IT technologies are introduced, building and IT infrastructure design must be flexible and adaptable to accommodate future new technologies so as not to disrupt ongoing business operations or cause excessively costly modifications to existing systems.

Design for IT flexibility requires consideration of all or some of the following:

• Adequate power for future building/system expansion including emergency power supply

• Adaptable power and telecommunication cores

• Adaptable dedicated electrical and telecommunications spaces

• HVAC delivery to dedicated IT spaces

• Network security

• Strategically located branch takeoffs and utility stubs

• Adaptable plenum systems—either overhead or underfloor, coordinated with space needs for parallel HVAC, power, lighting, and fire protection systems as applicable

• Overhead exposed cable trays integrated with parallel HVAC, power, lighting, and fire protection systems

Emerging Issues

Integrated Practice

The building industry has been focused on rapidly emerging technologies in building information modelling and interoperability that will radically change the process of design, fabrication, construction, and maintenance of buildings over their life cycle. These same technologies threaten to change traditional industry business and contractual relationships regarding inefficiencies due to design and construction industry fragmentation; risk distribution and ownership of design information; compensation methodology—value based vs. cost based fee determination; leveraging of project information knowledge early in the design process; and intellectual property compensation for knowledge stored in an A/E BIM to be modified by input of project-specific data.

The American Institute of Architects (AIA) has recently announced the establishment of the Integrated Practice Strategy Working Group (IPSWG), which brings AIA knowledge communities and committees together to discuss this potential redefinition of architectural practice.

Building Information Modelling (BIM)

Building Information Models (BIM) based on NIBS International Alliance for Interoperability (IAI) Industry Foundation Classes (IFC) is an emerging technology that enables accumulation and management of facility life-cycle information. IFC-BIM lets architects, engineers, construction managers, facility operators, and facility managers work with (and store for downstream users) tangible components such as walls and furniture, and also concepts such as activities, spaces, and costs.

BIM is a master, intelligent data model, resulting in an as-built database that can be readily handed over to the building operator upon completion of commissioning. The BIM standard could someday integrate CAD data with product specifications, submittals, shop drawings, project records, as-built documentation and operations information, making printed O&M and Systems manuals virtually obsolete.

Wireless Technologies

Organizational/business use of wireless technology is still seen as an adjunct to wire due to network security issues, although more advances have been made in the residential building market. GSA envisions an integrated workplace where plug and play technology enables components to be added to or removed from a basic service infrastructure grid with no rewiring.

The Centre for the Built Environment (CBE) at the University of California, Berkeley has wireless technology research projects in development for:

• A programmable wireless lighting control system that can be used in both retrofit and new lighting applications that greatly reduces the cost of wiring and switching, enables more flexible lighting control that can be integrated with daylight sensing, permits individual user control of workstation lighting, and potentially results in more energy efficiency.

• A combined wireless communication and micro-electromechanical (MEMS) sensor system for sensing, measurement, and control of the building indoor environment; enabling environmental sensing distributed over wider spaces; leading to optimization of building systems, greater energy efficiency, and individualized user comfort.

Smart Buildings

Tomorrow's "smart buildings" are expected to involve the dynamic interaction of building and information systems. Building materials and systems would sense internal and external environments, anticipate changes, and automatically make corresponding adjustments to maintain an optimized environment.

• Space lighting would be adjusted for differing daylight exposures and window control devices—blinds, louvers, environmentally reactive glass—would respond automatically.

• Wireless sensors would be embedded in building envelope materials to monitor performance and possible deterioration over time, and then give O&M management early notice of potential problems.

http://www.wbdg.org/design/dd_infotecheng.php