Construction method of cement concrete road
The construction method of the road is started once the site is fully prepared. It involves the following steps :-
Formwork: Normally, wooden sheets, battens, plywood, fibre hard board, steel plates, angles, rope etc. are utilized for form work.
Prior to start the form work, check that there should not be any type of materials like dust, cement.
The concrete should be set in proper depth and for this purpose, 2.5 – 5 cm thick and 3 mtr long wooden sheeting should be applied.
The depth should be identical with the level of slab thickness.
Once 24 hours are passed, form work is moved to the next length of road.
Watering of base: If the base of the road is dry or the construction starts all through the summer seasons, then water should be sprinkled on concrete. Then, the concrete should be arranged.
Construction of joints
Normally, three basic joint types are utilized in concrete pavement which range from contraction, construction and isolation.
Besides, isolation joints, all joints are arranged to tie up slabs mechanically. The connection facilitates dispersing a load enforced on one slab onto slabs along its perimeter.
To arrange transverse and longitudinal joints, the wedges of woods, metals should be affixed on level of concrete.
Once concrete is set, it should be removed.
Material mixing & setting of concrete
The concrete is mixed through mixer with cement, concrete, sand and water. The following types of mixers are normally applied throughout construction.
Batch mixer – Suitable for small road construction
Continuous mixer – Suitable for large construction
If the distance is long from the job site, mix concrete is transmitted to the site within setting time.
Placing of concrete - The following processes are utilized for concrete placement :-
Alternative bay method: Under this method, the concrete is placed on both sides of road alternately similar to 1,3,5 part at one side and 2,4,6 part other side. This system contains slow process because of road traffic issues.
Continuous bay method: Built up one side of road continually and once construction of some portion of first side is completed then built up other side. This method contains rapid process devoid of any obstruction of traffic.
Compaction of concrete: The compaction is done to extract air from void and make concrete solidified. The compaction is performed with mechanically surface vibrator and manually hand tempers.
Then, floating, screeding or strike off, bull floating and brooming is performed according to finishing purpose of concrete pavement to make the top surface smooth.
Curing: Once the finishing operations are completed, the surface of the pavement should be fully covered with wet hessian cloth, burlap or jute mats.
Curing means the method of enhancing the hydration of cement. After setting, the curing method is performed till 14 to 28 days.