Some Properties of Lean Mixture Concrete Containing Stabilized Sludge Water
Junji NAKAMOTO and Yoshitaka MITSUIWA
Abstract:Authors have been studying for about ten years as for the effective utilization of sludge water produced in ready mixed concrete plants due to washing of a mixer, agitating truck dram etc . Nowadays, JIS A 5308 permits the usage under 3 percent as solids of sludge for the unit cement content of new concrete. Recently, it is strongly requested to re-use a further large quantity of sludge water , in order to achieve the zero-emission. It is expected to re-use sludge water for concrete from the fact that sludge water consists of cement, fine particles of aggregate and water. This study, in order to utilize the larger quantity of sludge water than that now allowed, is to verify the properties of lean mixture concrete containing sludge which was designed for having the identical slump and compressive strength to comparative concrete. From the results of this study, it became clear that as for the lean mixture concrete containing stabilized sludge within the range of 3-9%, there was no problem about slump, bleeding, compressive strength, drying shrinkage and carbonation depth. Key Words:Zero-emission, In-plant recycle, Concrete sludge water, Setting retarder, Bulk volume of coarse aggregate, Slump, Bleeding, Compressive Strength, Blast furnace slag cement, Lean mixture concrete