论文部分内容阅读
大型工程常由拌合机来生产混凝土。混凝土是由水泥、碎石和砂加水拌合而成的。水和水泥的重量比(水灰比)对拌成的混凝土质量影响很大.在工地,由于砂的含水率经常变化.常破坏正常的水灰比。所以很需要随时测定砂的水分,以便及时调整加水量,保持正常的水灰比,从而保证混凝土的质量。 “取样——烘干——称量”法可以测定砂的水分.但由于每次测定需要1～2小时,不能用来及时调节加水量,更谈不上自动控制水分了。
Large-scale projects often use mixer to produce concrete. Concrete is made of cement, gravel and sand mixed with water. The weight ratio of water to cement (water-cement ratio) has a great influence on the quality of the concrete mixed in. Because of the frequent changes in the moisture content of the sand at the site, the normal water-cement ratio is often destroyed. So it is necessary to measure the moisture of the sand at any time in order to adjust the amount of water in a timely manner to maintain the normal water-cement ratio, so as to ensure the quality of concrete. “Sampling - drying - weighing” method can determine the sand moisture, but because each measurement takes 1 to 2 hours, can not be used to adjust the amount of water, let alone automatically control the water.