コンクリート塊から製造した再生骨材の諸特性

Abstract

Demolished Concrete debris has been recycled mainly for roadbeds and backfill. Improvement of the quality is necessary in order to use the concrete debris as recycled aggregate for concrete. The basis of the improvement purpose is to remove mortar and cement paste that adhered to the rock aggregate. Improvement method in this study is based on abrasion and crushing action. For the equipment, Los Angeles Machine in JIS A 1121 and forced mixing type mixer in JIS A8603 were used. In the raw material put into both testing equipment, 40mm recycled coarse aggregate used as a roadbed was used. Various impurities such as small amount of asphalt and fiber in the aggregate with large amount coarse debris were included in visual observation and under the microscope. At quality and energy consumption of improved recycled aggregate, there were differences between both testing equipments. For example, 3 time the time of Los Angeles machine was needed in the mixer in order to obtain the recycled aggregate of the quality of the same water absorption.