Curing time of concrete in winter construction
D.0.3 provisions on strength inspection of specimens under the same condition for structural entity inspection in appendix D of code for acceptance of construction quality of concrete structure: "the equivalent curing age and corresponding strength representative value of specimens under the same condition and natural curing shall be determined according to local temperature and curing conditions as follows:
1. The equivalent curing age recommended daily average daily cumulative temperature reaches 600 ℃ · d of the ages, 0 ℃ and below age not plan;The equivalent curing age should not be less than 14d, and should not be more than 60d;
2. The strength representative value of the curing specimen under the same condition shall be determined according to the strength test results in accordance with the provisions of the current national standard "concrete strength inspection and evaluation standard" GBJ107, and then obtained by multiplying the conversion coefficient;The conversion coefficient should be 1.10, or it can be adjusted according to the local test statistics.
Generally should be within 12 hours after casting and coverage, moisture curing of concrete curing time: using Portland cement and ordinary Portland cement and slag Portland cement mixing concrete, shall not be less than 7 days, with mixed with retarding admixtures or anti permeability for concrete shall not be less than 14 days, watering frequency should be able to maintain in the wet state, concrete curing water mixing water and should be the same, if you want to water on all bubble bubble, note: if the average temperature is lower than 5 Celsius, shall not be watered.Cover the cured concrete with a plastic sheet, covering all exposed surfaces tightly, and keep the condensed water inside the plastic sheet.