Degree; The flexural-tensile strength of surface concrete is not less than 4.5Mpa, and the flexural-tensile strength of expressway, main roads and heavy traffic is not less than 5Mpa.
2. Lime stabilized soil base, cement stabilized soil base, lime-fly ash mixture, graded crushed stone and graded gravel base
The curing period is 7~ 14 days.
3. In cement concrete pavement, the use of concrete admixture should be consistent, and the initial setting time is not small during high temperature construction.
Low-temperature construction with the final setting time not exceeding 10 hour within 3 hours.
4. The curing time of cement concrete pavement depends on the increase of concrete flexural strength, which is generally not less than.
Calculated by 80% of the flexural strength, it is generally 14~2 1 day. Pay special attention to the first 7 days of heat preservation (wet) curing. 5, bridge engineering concrete sprinkler maintenance time, using portland cement, ordinary portland cement,
Slag Portland cement concrete for not less than 7 days; Concrete with retarder, impermeability requirements and high strength shall not be less than 14 days.
6. The completion time of self-grouting of prestressed tendons after beam penetration shall meet the following requirements: air humidity >; 70% or salt
When the score is too large, 7 days; When the air humidity is 40%~70% 15 days; When the air humidity is less than 40%, 20 days.
7. In the shotcrete excavation method, early strength concrete is used for shotcrete, and the initial setting time is less than 5 minutes.
The final setting time shall not exceed 10 minute.
8. In the cast-in-place (prestressed) concrete pool, after the concrete pouring, it should be watered and maintained moist.
Less than 14 days.
Circuit diànlù, electrical? Circuit? Specifically, a conductive loop composed of metal wires and electrical and electronic components is called a circuit. The circuit through which direct current passes is called "direct current circuit"; The circuit through which alternating current passes is called an "alternating current circuit".