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目前,在泵送施工中仍存在着泵送过程中时有泵压陡升和阻泵的现象,这除与泵的机械性能有关外,混凝土拌合物的性质出是一个重要的影响因素。因此,研究混凝土的可泵性及其评价指标是十分必要的。根据泵送混凝土的实践经验和研究结果,一般都认为可泵性好的混凝土拌合物应有较好的流动性、稳定性和较小的摩阻力。从试验结果看,当水灰比不变时,砂浆体积越大,混凝土坍落度越大,流动性越好;而且坍落度与砂浆扩散度和砂浆体积的乘积成指数关系。由此可知,混凝土流动性主要取决于砂浆流动性和砂浆
At present, in the pumping process, there are still phenomena of steep pumping and blockage of the pump during the pumping process. Apart from the mechanical properties of the pump, the nature of the concrete mixture is an important factor. Therefore, it is very necessary to study the pumpability of concrete and its evaluation index. According to the practical experience and research results of pumped concrete, it is generally considered that good pumpable concrete mixes should have good fluidity, stability, and low frictional resistance. From the test results, when the water-cement ratio is constant, the larger the mortar volume, the greater the concrete slump, the better the fluidity; and the slump and exponent of the product of mortar diffusion and mortar volume. It can be seen that the flowability of concrete depends mainly on the mortar fluidity and mortar