The formation of concrete is a slow solidification process. It takes 28 days to reach the design strength from the initial setting to the final setting, in which continuous curing is required, especially 7 days after the initial setting, so that the concrete must maintain enough moisture.
Adding 1.5 ~ 2.0% steel fiber with a length of 25 ~ 60mm and a diameter of 0.25 ~ 1mm into concrete can improve the ultimate compressive strength and ultimate flexural tensile strength by more than 50% compared with plain concrete.
Extended data:
Cement characteristics:
Advantages:
(1) high strength.
(2) Good stability.
(3) Good durability.
(4) Low maintenance cost.
(5) Good skid resistance.
(6) It is good for driving at night.
Disadvantages:
(1) There is a great demand for cement and water. Building a 20 cm thick and 7 m wide cement concrete pavement will consume 400~500 tons of cement and about 250 tons of water per kilometer.
(2) There are many seams.
(3) It opened to traffic late.
(4) Maintenance and repair difficulties.
Baidu encyclopedia-cement