Method and apparatus for testing ready-mixed concrete

摘要

Concrete with a known cement mixing ratio is sampled and the aggregate is screened out. A fixed quantity of the resulting mortar is weighed, stirred with waterand allowed to stand. The mortar sample is then immersed in water and again weighed. A linear relationship between the water-to-cement ratio of the concrete and the ratio of the weight of the mortar under water to that out of waterthen allows the water-to-cement ratio w/c to be read off from a graph. This then serves as a measure of the quality of the hardened concrete.;An apparatus for carrying outthe method automatically is also described.