2002 年 13 巻 1 号 p. 33-42
We have proposed a method of reusing waste fresh concretes, now being treated in ready-mixed concrete plants, as a preceding mortar for concrete pumping constructions taking into consideration of the resource saving and control of construction waste emissions. A super set-retarding agent to halt thecement hydration and a superplasticizer to improve the fluidity were added to the waste fresh concretes, and the subsequent wet-screening resulted in Eco mortar that can be used as a preceding mortar for concrete pumping constructions. This paper deals with the quality of Eco mortar obtained from waste fresh concretes with various type of raw materials and with different ages after mixing. A full-scale pumping constructions was also executed on site using Eco mortar manufactured in a ready-mixedconcrete plant in the previous day, resulting in a confirmation of the feasibility of Eco mortar.