CONSTRUCTION INDUSTRY

In the fields of architecture and civil engineering, CONSTRUCTION is a process that consists of the building or assembling of infrastructure. Far from being a single activity, large scale construction is a feat of human multitasking. Normally, the job is managed by a project manager, and supervised by a  construction manager, design engineer, construction engineer or project architect. For the successful execution of a project, effective planning is essential. Involved with the design and execution of the infrastructure in question must consider the environmental impact of the job, the successful scheduling, budgeting
construction site safety, availability of building materials, logistics, inconvenience to the public caused by construction delays and bidding, etc.

In general, there are four types of construction: (1) Residential Building construction, (2) Industrial construction, (3) Commercial Building construction, (4) Heavy Civil construction. Each type of construction project requires a unique team to plan, design, construct and maintain the project.

Definition:

Businessdictionary.com - Sector of national economy engaged in preparation of land and construction, alteration, and repair of buildings, structures, and other real property.

Construction Industry - Construction is a high hazard industry that comprises a wide range of activities involving construction, alteration, and/or repair. Examples include residential construction, bridge erection, roadway paving, excavations, demolitions, and large scale painting jobs. Construction workers engage in many activities that may expose them to serious hazards, such as falling from rooftops, unguarded machinery, being struck by heavy construction equipment, electrocutions, silica dust, and asbestos. The information, tools, and resources provided in these Construction Industry web pages are designed to assist those in the industry - whether worker or employer - to identify, reduce, and eliminate construction-related hazards.

The first huts and shelters were constructed by hand or with simple tools. As cities grew during the Bronze Age, a class of professional craftsmen, like bricklayers and carpenters, appeared. Occasionally, slaves were used for construction work. In the Middle Ages, these were organized into guilds. In the 19th century, steam-powered machinery appeared, and later diesel- and electric powered vehicles such as cranes, excavators and bulldozers. Architecture and construction involves creating awesome structures that can show the beauty and creativity of the human intellect. Fast-track construction has become more popular in the 21st century, with some estimates suggesting that 40% of projects

In the United States, the industry has around $850 billion in annual revenue according to statistics tracked by the Census Bureau, with an $857 billion annual rate in March 2013, of which $600 billion is private (split evenly between residential and nonresidential) and the remainder is government. As of 2005, there were about 667,000 firms employing 1 million contractors (200,000 general contractors, 38,000 heavy, and 432,000 specialty); the average contractor employed fewer than 10 employees. As a whole, the industry employed an estimated 5.8 million as of April 2013, with a 13.2% unemployment rate.

There are many routes to the different careers within the construction industry. There are three main tiers based on educational background and training, which vary by country:

·Unskilled and semi-skilled – General site labor with little or no construction qualifications.

·Skilled – Tradesmen who've served apprenticeships, typically in labor unions, and on-site managers who possess extensive knowledge and experience in their craft or profession.

·Technical and management – Personnel with the greatest educational qualifications, usually graduate degrees, trained to design, manage and instruct the construction process.

Skilled occupations include carpenters, electricians, plumbers, ironworkers, masons, and many other manual crafts, as well as those involved in project management. In the UK these require further education qualifications, often in vocational subject areas. These qualifications are either obtained directly after the completion of compulsory education or through "on the job" apprenticeship training. In the UK, 8500 construction-related apprenticeships were commenced in 2007.

Technical and specialized occupations require more training as a greater technical knowledge is required. These professions also hold more legal responsibility. A short list of the main careers with an outline of the educational requirements are given below:

·Quantity surveyor – Typically holds a master's degree in quantity surveying. Chartered status is gained from the Royal Institution of Chartered Surveyors.

·Architect – Typically holds 1, undergraduate 3 year degree in architecture + 1, post-graduate 2 year degree (DipArch or BArch) in architecture plus 24 months experience within the industry. To use the title "architect" the individual must be registered on theArchitects Registration Board register of Architects.

·Civil engineer – Typically holds a degree in a related subject. The Chartered Engineer qualification is controlled by the Engineering Council, and is often achieved through membership of the Institution of Civil Engineers. A new university graduate must hold amaster's degree to become chartered, persons with bachelor's degrees may become an Incorporated Engineer.

·Building services engineer – Often referred to as an "M&E Engineer" typically holds a degree in mechanical or electrical engineering. Chartered Engineer status is governed by the Engineering Council, mainly through the Chartered Institution of Building Services Engineers.

·Project manager – Typically holds a 4-year or greater higher education qualification, but are often also qualified in another field such as quantity surveying or civil engineering.

·Structural engineer – Typically holds a bachelors or master's degree in structural engineering. A P.ENG is required from the Professional Engineers Ontario. (ON,CANADA) New university graduates must hold a master's degree to gain chartered status from the Engineering Council, mainly through the Institution of Structural Engineers (UK).

·Civil Estimators are professionals who typically have a background in civil engineering, construction project management, or construction supervision.

In 2010 a salary survey revealed the differences in remuneration between different roles, sectors and locations in the construction and built environment industry.  The results showed that areas of particularly strong growth in the construction industry, such as the Middle East, yield higher average salaries than in the UK for example. The average earning for a professional in the construction industry in the Middle East, across all sectors, job types and levels of experience, is £42,090, compared to £26,719 in the UK. This trend is not necessarily due to the fact that more affluent roles are available however as architects with 14 or more years experience working in the Middle East earns on average £43,389 per annum, compared to £40,000 in the UK. Some construction workers in the US/CANADA have made more than $100,000 annually, depending on their trade.

Construction is one of the most dangerous occupations in the world, incurring more occupational fatalities than any other sector in both the United States and in the European Union. In 2009, the fatal occupational injury rate among construction workers in the United States was nearly three times that for all workers.  Falls are one of the most common causes of fatal and non-fatal injuries among construction workers. Proper safety equipment such as harnesses and guardrails and procedures such as securing ladders and inspecting scaffolding can curtail the risk of occupational injuries in the construction industry.  Other major causes of fatalities in the construction industry include electrocution, transportation accidents, and trench cave-ins.

The construction of the homes and buildings in which people live and work has been a major industry ever since early human beings first made huts of sticks, mud, or rocks. Methods of building construction have been constantly improved since those first crude structures. The world’s largest office building, the Pentagon in Arlington, Virginia, USA has 344,243 square metres of office and other space. Scar Tower in Chicago, the world’s tallest building, is 443 metres high.

India’s Taj Mahal required 20,000 workers and took from 1632 until 1653 to complete. Modern skyscrapers can be built within a year or two. Prefabricated buildings, with their various parts made in factories by assembly line methods, can be built in a day or two but are rarely as durable as traditionally made buildings.

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A Message From The Industry

Published on Oct 9, 2012

Construction industry professionals talk about the benefits of a career in construction

Parts of a building

A building has two main parts, the substructure the part below ground and the superstructure the part above ground. The substructure is usually called the foundation. It include the basement walls, even though these may extend above the ground.

Both the substructure and the superstructure help to support the load (weight) of the building. The dead load of a building in the total weight of all parts. The live load is the weight of the furniture, equipment, stored material and occupants of a building in some regions, the wind load of a building is important if the structure is to withstand storms. The snow load may also be an important factor. In some areas, buildings have to be constructed to withstand earthquake shocks.

Foundations are the chief means of supporting a building. They carry both the dead and live loads. There are three main types of foundations: (1) spread, (2) pier, and (3) pile.

 Spread foundations are long slabs of reinforced concrete that extend beyond the outer edges of the building. Such foundations are not so firm as those based on solid rock. The footing areas in contract with the soil must be of sufficient size to spread the load safely over the soil and to avoid excessive or uneven settlement. Any such settlement would cause walls to crack or doors to bind.

Pile foundations are long, slender columns of steel, concrete or wood. Machines called pile drivers hammer them down as deep as 60 metres to a layer of solid soil or rock. Workers can tell when the columns reach their proper depth by the number of blows, the pile driver needs to drive the columns a few centimeters deeper. These columns transmit the building load to the supporting soil. These columns transmit the building load to the supporting soil. Most skyscrapers are supported by rock foundations.

Beams, girders and columns support a building much like homes support the body. They form the skeleton of the superstructure and hear the weight of the walls and each floor of the building. Beams and girders run horizontally. Girders are usually larger than beams. Closely, spaced beams are called joists, especially in wooden buildings. Purlins are small beams that brace rafters or girders and help provide the structure to support roofs. Beams above window and door openings are called lintels. Slabs are beams whose width is greater than their depth.

Columns are heavy vertical supports that carry the load of beams and girders. Trusses consist of many woods or steel supports that are connected in triangular patterns. They provide the strength and rigidity to span large distances with relatively small amounts of material Arches are curved supported that usually extend over openings.

Types of construction

In load–bearing-wall construction the walls transmit the load to the foundation. In skeleton construction, all loads are transmitted to the foundation by a rigidly constructed framework made up beams, girders, and columns. This skeleton carries the roof, walls, and floors, together with their loads. Load-bearing-wall construction is usually most economical for buildings less than four storeys high, but skeleton construction is better for taller buildings. All buildings in the skyscraper class are of skeleton construction. The first building to have skeleton construction was the 10-storey Home Insurance Building in Chicago. Completed in 1885, this building was the world’s first skyscraper.

Many part of a building have no structural function. Partition walls and curtain walls carry only their own weight and serve to divide the interior or a building or to keep our the elements. Other nonload-bearing parts include windows, doors, stairs, and lifts.

In one method of construction, called tilt-up construction concrete wall panels are formed at ground level. Cranes or derricks then lift them into position. Lift-slab construction may be used for positioning roof and floor slabs. These slabs are formed with concrete at ground level, within the framework of the building. They are then lifted into place using hydraulic jacks.

Classification of buildings

Buildings are classified in many countries according to their resistance to fire. A standard fire test is used in testing samples of materials. In this test, the samples are graded for their ability to withstand the fire. For example, a two-hour rating is given to a material that withstands the test for two hours.

If the walls of a building are of masonry or reinforced concrete and the major structural parts steel or reinforced concrete and insulated, they would probably have a four-hour rating. Other parts of the building would have a three-hour rating.      

Ordinary construction is that in which the exterior walls are of masonry or reinforced concrete and in which the interior structural members are partly or entirely of wood in smaller dimensions than required for heavy timber or steel construction.

Frame construction, in which exterior walls are wholly or partly of wood is common in the USA and Scandinavia. It includes brick of stone veneer, stucco, or sheet metal over wood.

Construction a skyscraper

New methods in the design and construction of skyscrapers have been closely related to the development of computers. Engineers use computers to solve the complex projects. Computers do this work quickly by breaking the design down into a limited number of precalculated elements.

When an organization decides to erect a skyscrapers it usually signs a contract with a building firm. The company awards the contract after many firms have submitted bids showing the price they will charge and the time they will need to erect the building. The company that receives the contract must make detailed building plans so that construction can be done as quickly and as cheaply as possible. The construction firm often subcontracts to other companies such work as electrical wiring, plumbing and bricklaying. Such subcontracting saves money because it means using a worker only when the production schedule requires the individual’s services.

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The world's 200 largest construction companies

Uploaded on Jul 28, 2011

Chris Sleight, editor of International Construction magazine, looks at the World's 200 largest construction companies. This year's ranking of the world's 200 largest construction companies has seen China's largest contractors solidify their position at the top of the table, taking four of the top five places. Further down the ranking there have also been significant gains for smaller Chinese contractors.

Before construction begins, engineers determine the strength of the soils that will be lie underneath the new building. With the information, they can design the foundation. After the building site is cleared, leveled and drained of water, excavation (digging) begins.  Mobile diggers usually excavate the foundation. Ground made of rock may be excavated by blasting.

Sometimes workers dig a trench on all sides of the foundation and till it with concrete before excavation  begins. Any excavation that may cave in is braced and shored with wood steel. Pumps can be used to keep water from the excavation area at all times. But if the soil becomes too watery, caissons (protective walls) may be built so the work can continue.

After the excavation is finished, the footings (base) and the superstructure are built. Most steel used in the superstructure, such as beams, girders, and columns, come prefabricated. Each piece of steel should have a number of indicating the exact place where it should be used. When the steel is raised into place, workers fasten the pieces together temporary with bolt. Later, bolters and riveters join these pieces together permanently.    

Many kinds of derricks and cases are used in the construction of skyscrapers. The two  main kinds  are mobile cranes and tower cranes. Mobile cranes are mounted on trucks or special vehicles and can manoeuvre around the outside of the building to hoist materials and equipment from various locations. Tower cranes are supported on a steel erected next to or inside a building’s framework. They can only hoist materials positioned within the maximum radius of their lifting mechanisms. Some tower cranes can add sectors to increase the height of their support tower as the building goes up. Others are mounted directly on the recently constructed upper storeys of the building’s framework. They can use a “telescoping” tower mechanism to “jump” up with successive floors as they are constructed. A derrick, mobile crane, or even a helicopter can help in removing sections of a tower crane once the building  is nearly complete.

After workers complete the superstructure and outside walls, the building is ready to be finished, decorated and furnished. These steps are much like finishing a house.

Prefabricated construction

Prefabricated has become an important part of most types of building construction. Prefabricated sections of a building are produced in large quantities in a history and then shipped to various construction sites. This procedure may allow work to continue despite poor weather conditions and should reduce any waste in time and material at the site. As a result, costs are lowered and construction time decreases.

Many types of building sections can be prefabricated. For example, entire walls may be prefabricated for a wooden-frame house. Huge wooden arches are prefabricated for use as supporters in churches, gymnasiums, and other buildings. Concrete beams, floors, roofs and wall panels may be precast for many types of structures. Entire buildings may be constructed in a history and then transported to the desired location.

Prefabricated structures are sometimes made by a process called modular construction, first used in Japan. Modular construction refers t the use of a standard measurement as the basis for all building materials. The size of the module may vary considerably from country to country.  In the United State, the basic module is 10 centimeters.  All building parts are designed so that each dimension equals either this measurement or some multiple of it. Such standardization of building parts can allow all parts to fit together with few alterations. Modular parts are also used in buildings that are not prefabricated.

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