The general situation
1. The maintenance time of the overall surface layer of the ground is 7d(5Mp before the person);
2. before painting, mortar layer maintenance 7d, concrete layer maintenance 28d;
3. waterproof concrete curing 14d;
4. cement mortar waterproof layer construction, base plaster or concrete maintenance strength is not less than 80%;
5. cement mortar waterproof layer curing time 14d, temperature is not less than 5°;
6. the main concrete, Portland cement, ordinary Portland cement, slag Portland cement curing 7d, volcanic ash, fly ash cement, curing 14d, adding retarder, mineral additives or impermeable concrete, curing time 14d;
7. large volume concrete, ordinary Portland cement curing time 14d, slag, ash cement, curing time 21d.
Rule summary:
1. Generally, there are three kinds of curing time: 7d, 14d and 21d;
2. Those with waterproof and impermeable requirements are generally 14d;
3. large volume concrete requirements are higher.
4. for slag, volcanic ash, fly ash cement concrete curing time is generally longer than Portland cement curing time, reason: slag, volcanic ash, fly ash has potential hydration, can cause secondary hydration after cement hydration, so the curing time should be longer, is conducive to strength. Concrete pouring pound and cement mortar plastering finished, the reason to watering maintenance: concrete pouring pound and plastering project after completion, will gradually solidify, hardening, this process mainly by the hydration of cement to achieve, and hydration must be in the appropriate temperature and humidity conditions to complete. Therefore, in order to ensure the suitable hardening conditions of the root soil, so that its strength continues to grow, it is necessary to carry out watering and maintenance in time after construction.
Maintenance method: Cover with warm straw bag, wet gunny bag, wet straw and warm sand, and water regularly to keep it moist. Water every 2 hours on a clear day. The starting and ending time of concrete watering and curing: when ordinary cement is used, the continuous wet curing shall be no less than 7 days and nights after pouring 12 hours; When using slag cement or volcanic ash cement, watering and curing after 20 hours of pouring should not be less than 14 days and nights; For concrete with impermeability requirement and concrete mixed with plasticizer, curing should be no less than 14 days and nights.
Summary of maintenance time of common construction technology:
1. the concrete has been poured, should be in the concrete before the final setting (usually for the concrete after the completion of 8 ~ 12h) begin natural curing.
2. after pouring belt: should be in the pouring after the completion of 12h to cover the concrete moisturizing maintenance.
3. cement mortar plaster layer should be cured under humid conditions, generally should be plastered after 24 hours.
4. Cement-based permeable crystalline waterproof layer and waterproof mortar layer do 3-7d spray curing evenly, and then do water storage test after curing.
5. Concrete pouring completion: 1) Cover and moisturize within 12h. 2) watering and curing time, for the use of Portland cement, common silicon cement, slag cement mix concrete, not less than 7 days, for the use of slow setting admixture or impermeability requirements, not less than 14 days.
6. After the construction of the overall surface layer, the curing time should not be less than 7d, and the compressive strength should reach 5MPa.
7. ceramic tile surface layer: when the brick surface layer shop pasted within 24 hours should be maintained, maintenance time should not be less than 7d.
8. stone veneer construction: when the large stone surface layer shop should be finished maintenance, maintenance time shall not be less than 7d; When the brick surface layer is laid and pasted, maintenance should be carried out within 24 hours, and the maintenance time should not be less than 7d.
9. The post-pouring belt shall be retained for at least 28d and maintained for at least 15d of moist curing.
10. cement mortar waterproof layer, curing temperature is not less than 5 degrees and maintain moist curing time is not less than 14d.
11. The duration of moisturizing and curing for bulk concrete shall not be less than 14d.
12. large volume concrete: when using ordinary Portland cement, curing time shall not be less than 14d, when using slag cement, ash cement curing time shall not be less than 21d; Waterproof concrete should be cured immediately after final setting, and the curing time should not be less than 14 days.
13. Waterproof construction of post-pouring belt:
1) The age of concrete on both sides shall reach 42d.
2) The curing time is not less than 28d.
14. The standard curing age is 28d, and the compressive strength is tested.
15. Waterproof concrete should be cured immediately after final setting, and the curing time should not be less than 14d.
16. Shotcrete should be cured 2h after final setting, and the curing time should not be less than 14d. When the temperature is lower than 5 degrees, spray curing is not allowed.
