In this study, we focus on the Ready-mixed concrete factory using recovered aggregate for concrete as building materials. We interviewed with fourteen Ready-mixed concrete factories, about equipment of collecting recovered aggregate system, products, others and we tested physical properties about aggregate. The results show the following points: (1) 40% of a questionnaire respondent was held equipment of collection recovered aggregate (2) addition method A need to device to put aggregate impartial (3) some physical properties is different between original aggregate and recovered aggregate.
