Mix Design of Concrete with Air-Entraining and High Range Water-Reducing Admixture Containing Stabilized Sludge Water

Authors have been studying for several 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 content of cement 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. Sludge water consists of cement, fine particles of aggregate and water. All materials are one of the constituents of concrete. This study, in order to utilize the larger quantity of sludge water than that now allowed, is to verify the mix design of concretes containing sludge which has identical slump and compressive strength to comparative concrete. From the results of this study, it became clear that as for the high-range water reducer concrete containing stabilized sludge within the range of 3-15%, there was no problem about slump and compressive strength. It was possible to design the concrete of identical slump and compressive strength to comparative concrete. It was also confirmed that the bulk volume of coarse aggregate was available for the design method of concrete mixture.