The flexural and tensile strength of cement concrete pavement is controlled by cement concrete at the age of 28 days. The flexural-tensile strength of the surface concrete should not be less than 4 MPa and 5Mpa, and the flexural-tensile strength of expressways, main roads and heavy traffic should not be less than 5Mpa.

1. The curing period of lime stabilized soil base, cement stabilized soil base, lime-fly ash mixture, graded crushed stone and graded gravel base is 7~ 14 days.

2, cement concrete pavement, the use of concrete admixture should comply with, high temperature construction, the initial setting time is not less than 3 hours, low temperature construction, the final setting time is not more than 10 hour.

3. The curing time of cement concrete pavement depends on the increase of concrete flexural strength, which is generally not less than 80% of the designed flexural strength, and is generally 14~2 1 day. Pay special attention to the first 7 days of heat preservation (wet) curing.

4, bridge engineering concrete sprinkler maintenance time, using portland cement, ordinary portland cement, slag portland cement concrete not less than 7 days; Concrete with retarder, impermeability requirements and high strength shall not be less than 14 days.

5. The completion time of self-grouting of prestressed tendons after beam penetration shall meet the following requirements: air humidity >; 70% or too much salt, 7 days; When the air humidity is 40%~70% 15 days; When the air humidity is less than 40%, 20 days.

6. In the shotcrete excavation method, the shotcrete adopts early strength concrete, and the initial setting time is not more than 5 minutes, and the final setting time is not more than 10 minutes.

7, cast-in-place (prestressed) concrete pool, after concrete pouring should be covered with sprinkler maintenance, keep wet?

Less than 14 days.