3.3 transported to the pouring site shall meet the requirements of concrete slump, when segregation occurs, secondary mixing, stirring time is determined by experiment. It has been forbidden to transport to any location concreting with water. 3.4 from the stirring, transportation, pouring into the mold, the temperature is not higher than 25 ℃, duration of not more than 90min, when the temperature is higher than 25 ℃, should not be greater than the duration of 60min. When the admixture or admixtures used in hydraulic cement concrete is rapid, the duration should be determined by experiment