The construction of concrete buildings is different from one structure to another based on the size, complexity, function, and materials of the building. Additionally, soil types, environmental conditions, availability of local skilled labor and construction equipment, and construction material availability would also affect the construction process.
Generally, building construction activities are divided into two major groups; pre-contract activities and post-contract activities. The former refers to activities before a contract is made for the construction of the works. In contrast, the latter refers to activities after a contract is made for the works' construction. In this article, a general procedure for the construction of concrete buildings is presented.
Preconstruction activities
1. Location of Project
A building's location needs to be specified properly to avoid future problems due to soil types or any other issues. Sometimes, there is not much room for selecting a building site, hence problems if present need to be tackled properly.
2. Building Plan
The plan of a building is set by architectural engineers based on the requirements of the building.
3. Building Design
After the building plan, a structural engineer designs the frame of the structure. The type of foundation is then determined and designed based on soil investigation and a load of the superstructure.
4. Prepare Estimate and Budget
The building estimator estimates material quantity, a number of different items of works, and prepares a sheet that contains the cost of the building construction.
5. Soil Investigation Report
The soil investigation report should be prepared before the design of the structure. The geotechnical engineer or structural engineer needs to know the properties of the soil in the construction site otherwise, the foundation design cannot proceed. The soil investigation report contains soil properties, types of soils, the load-bearing capacity of the soil, etc. To read more on soil investigation, please click here.
6. Building Permit
Grant approval of the City Development Authority is required to start the construction activities. Taken approval may need certain documents such as a soil investigation report, all drawing like plan; elevation; section, land survey, structural report.
7. Specify a Builder
The selection of a builder is significant since it is essential for the building's successful construction within the time frame. All details of the project should be clearly described in the contract document. The conditions of the contract need to be completely checked before sign the document.
Post-contract Activities
1. Site Works
Site preparation is the first activity of post-contract construction work. It involves cleaning the project site from debris and roots of trees, removing obstructions such as loose soil, old building if present, sloping grounds, and specifying the position of underground services are present and relocating them if necessary.
2. Site Surveying and Layout
After cleaning the building site, the building's layout is established with the help of surveying equipment such as level, theodolite, total station, etc. In this stage, the precise position of the building is determined based on the drawings.
After that, the location of access roads to the construction site, storage areas for construction materials, drainage system location, dormitory for labors, and offices are specified. The relationship between different offices and facilities in construction site need to be considered.
To read about how to prevent errors during setting out of buildings, please click here.
3. Excavation
After setting up the structure's layout, the excavation process begins using suitable machines based on the type of soil and size of the excavation work. The excavation work is carried out with the help of surveying equipment to reach the required depth based on the design drawings.
Safety precautions are considerably crucial both during the excavation process and after its completion to prevent undesired events and save the life of labors and civilians and avoid delays in the construction process. If the excavation is in an urban area, then one should be aware not to damage underground services
4. Compaction of Excavation Bottom
After designated depth is reached, the bottom of the excavation trench needs to be compacted to reduce possible future settlement. Various machines such as smooth wheel roller, sheep foot roller, rubber tire, crawler, and tamping plate compactor can be used to achieve the required degree of compaction, which is 90% based on international building code.
5. Foundation Construction
Foundation is the lowest part of the building responsible for transferring loads from the structure to the soil underneath. So, it needs great care and precision during construction.
The construction process may include placing plain cement concrete alone or combined with rubble soiling at the bottom of the foundation to create a level surface, set up formworks, place reinforcements, pour concrete, and finally cure the concrete get the designated strength.
The site engineer should supervise all activities to ensure that the entire work is executed according to the project specifications, and the labors' safety needs to be considered.
6. Plinth Beam Construction
Based on the type of foundation, a plinth beam may be constructed to connect different footings and provide a level surface for the construction of the superstructure.
7. Column Construction
After the construction of the foundations and plinth beams is present, a reinforced concrete column would be constructed. The procedure involves constructing a column kicker, placing steel bars, setting up formwork, pouring concrete, and curing the concrete.
Checking the verticality of columns during their constructions is crucial to avoid a deviation from their positions. The columns are constructed to the level of the slab, and their reinforcements should be extended to allow the construction of the above storeys.
8. Slab and Beam Construction
After the construction of columns on the ground floor is ended, the construction of slab and beams would begin. The process involves placing formworks for beams and slabs, installing reinforcements for beams and slabs based on drawings, embedding other objects is present, pouring concrete for beams and slabs, and finally cure the concrete properly.
The sequence of constructing columns, beams, and slabs are followed for other storeys above. The site engineer needs to monitor all activities and ensure that they are conducted according to project specifications.
9. Masonry Wall Construction
When the construction of columns and beams is completed, the masonry wall construction will begin.
10. Lintels
Lintels span openings such as windows and doors to carry masonry work over them.
11. Roof Slab
When all storey of the building is constructed, the roof slab is built based on the specifications and details of the building design.
12. Plumbing and Electrical Works
These activities may be not be related entirely to the work of a civil engineer. However, the site engineer should prevent any actions that detrimentally effect structural elements like piercing beams, which are sometimes done carelessly, if not accounted for in the design stage.
13. Finishing Works
Finishing works such as external plastering begins after the construction of the structure. Internal walls are plaster with a smooth finish, and flooring is done with tiles. Later on, the walls are painted or textured.
14. Roof Finishing
Sometimes, the roof surface is waterproofed to avoid leakage.
12. Completion Certificate
After finishing the work, the contractor can apply for a completion certificate from authorities. Local authorities would check completion documents for compliance with building specifications.
FAQs
The construction process of concrete building includes cleaning and grading of project site, layout building plan, excavate trenches for foundations, and construct foundations; plinth beams; columns; beams; and floor slabs. This process is repeated from column construction till the roof of structure in case of multistory buildings.
The site investigation is conducted to evaluate engineering properties of soil in the project site upon which the design of foundation is based.
The bottom of the excavation trench needs to be compacted to reduce possible future settlement.
Read More:
Methods of Soil Investigation and Soil Exploration and their Details