Construction Work
Construction Work
work performed at a construction site in erecting buildings and structures. Construction work may be general or specialized. General construction work is classified according to the materials being used or processed or according to the structures being built as reinforcement placement, concreting, earthwork, masonry, roofing, finishing, carpentry, piling work, erection and installation, and other types. Specialized work includes waterproofing, heat insulating, sanitary-engineering work, and electrical installation work. Some construction work is designated according to the parts or components of the buildings and structures being erected, for example, cribbing, furnace work, and flooring, or according to environmental characteristics, for example, winter work, underground work, and underwater work. Depending on the work sequence, construction work is divided into two groups: preparatory and principal work (the latter includes all general construction work). Ancillary work, for example, the shoring of trenches, installing of scaffolding, lowering of the level of ground water, and compacting of soil, and concealed work together constitute a separate category.
Each type of construction work consists of a series of separate but related construction processes. Depending on the method used to conduct the work and on the complexity, these processes are classified as integrated-mechanized, mechanized, and manual. In modern construction all the basic forms of heavy and labor-consuming work, such as earthwork, concreting, and plastering, are usually performed by construction machines or with the aid of power tools and accessories. Manual tools are used only when unavoidable or for small volumes of work. With increasing industrialization in construction, construction work has become closer to assembly and installation work, that is, the mechanized assembly and finishing of buildings using components and parts prefabricated by industrial enterprises. This means that the most laborious processes are performed at factories, the structural components and parts are consolidated into larger units, and the degree of prefabrication is increased. Thus, for example, conveyor assembly and the installation of large blocks for roofing industrial buildings (seeTOTAL-PREFABRICATED CONSTRUCTION) are being incorporated into industrial construction in the USSR.
Construction work on a project or on parts of a project may be performed sequentially, in parallel, or as a production line. The most efficient organization is achieved by production-line construction, in which the construction processes are performed in a specified organizational and technological sequence. This results in high productivity and smooth production flow in the work itself, a stable rate of construction, and the most effective use of material and technical facilities.
Construction work is usually carried out by a general contracting organization (general contractor), which enlists appropriate organizations (subcontractors) to perform specialized work. The activities of various construction divisions are coordinated by a system of network planning and control, which also provides a production-line organization for the construction work as a whole. In order to increase labor productivity, construction work should be performed in strict conformity with previously developed plans for the organization of construction and individual operations. The completion dates and the sequence of individual construction processes in the completion of a specified amount of work with a given set of machines and tools are regulated by a special document called a flow chart. The quality requirements for construction work and the regulations for the completion and acceptance of work are set forth in the Construction Code.
Construction engineering comprises the various methods used to perform construction work. The constant improvement of construction processes resulting from industrialization and integrated mechanization ensures a steady rate of increase in labor productivity, lower labor expenditures, fewer work-related illnesses and injuries, improved quality, and cheaper construction. Research in construction engineering, the generalization of advanced methods for organizing labor, and the mechanization of construction work have made it possible to develop systems of high-efficiency machines and tools for use in construction.
In order to ensure the completion of the ever-increasing volume of construction work without increasing the number of workers, consideration is being given to further improving the methods of individual construction jobs by means of the integrated mechanization and automation of labor-consuming processes. For example, in order to reduce the amount of final leveling work in digging foundations, special machines are being developed that are equipped with servomechanisms; the servo-mechanisms automatically ensure that the level of the foundation is accurate. In order to reduce labor expenditures for work with frozen ground, the use of explosives is being introduced. The manual processes for setting up and binding reinforcing bars for reinforced concrete are being eliminated by using large-size welded cages and frames that are fabricated automatically and installed by machines.
Substantial reductions in labor and material requirements for construction and reductions in the amount of transportation and erection required will result from the increased production of efficient structural components, materials, and products. These include high-strength concretes, porous aggregates, structural components made from light alloys and components that use plastic, and almost totally prefabricated roofing, heat-insulating, and finishing materials. Increased production of such items will result in further improvement in construction engineering. If improved mechanized and hand tools are developed, substantial increases in labor productivity are possible in finishing, installation of power supply systems and sanitary fixtures and other types of laborious construction work that involve many operations.
REFERENCES
Marionkov, K. S. Osnovy proektirovaniia proizvodstva stroitel’nykh rabot, 2nd ed. Moscow, 1968.Ganichev, I. A. Tekhnologiia stroitel’nogo proizvodstva. Moscow, 1972.
Tekhnologiia stroitel’nogo proizvodstva, 2nd ed. Kiev, 1973.
V. M. MINTS