Some Properties of Concrete Incorporated Sludge
Junji NAKAMOTO, Kazuo TOGAWA and Yoshitaka MITSUIWA
Abstract:As for the effective utilization of sludge water containing cement and fine particles of aggregate, authors have been studying for several years. Nowadays, JIS A 5308 permits the usage under 3 percent as solids of sludge for the unit content of cement. This study, in order to utilize the larger quantity of sludge water than that now allowed in the mixing plants, is to obtain the basical data on the properties of fresh concrete and of hardened concrete. Especially, the both influence of unit content of cement of new concrete and of particle size of aggregate contained in the sludge has been discussed experimentally on the view points of slump, bleeding, compressive strength and drying shrinkage. From the results of this study, it was clarified that a good quality concrete could be obtained regardless of the unit content of cement and particle size of sand in sludge, even though the sludge mass of 9 % of cement content and the sludge age of 3 days, provided that setting retarder was used adequately. Key Words:Concrete sludge, Reuse, Mixing water, Properties of fresh concrete, Properties of hardened concrete