在夏季,搞好泵送混凝土的长途运输,主要应考虑混凝土的坍落度损失和初凝时间的控制,需注意以下几个方面。1.严格按泵送混凝土的要求控制原材料,特别是碎石规格的控制。泵送混凝土要求碎石最大粒径与输送管内径之比不宜大于1:3,砂子要求通过0.35毫米筛孔的不少于15%,水泥应尽可能选用低水化热水 In the summer, for the long-distance transport of pumped concrete, the loss of concrete slump and the control of the initial setting time should be taken into consideration. The following aspects should be noted. 1. Strictly control the raw materials according to the requirements of pumping concrete, especially the control of the specifications of gravel. Pumped concrete requires that the ratio of the maximum particle size of the gravel to the internal diameter of the conveying pipe should not be greater than 1:3, the sand should pass no less than 15% of the 0.35 mm mesh, and the cement should use low-calcification water as much as possible.