CONCRETE FOR STRUCTURE OF CIVIL ENGINEERING AND CONSTRUCTION FOR RECYCLING

摘要

PROBLEM TO BE SOLVED: To obtain the subject concrete which can wholly be used as a reclaimed aggregate, has a largely unchanged slump and good adhesivity, and enables the recycling of the resource, by specifying a unit binder content and the compression strength of a cured concrete product. SOLUTION: This concrete of civil engineering and construction structure for recycling has a unit binder content of 200 to 500 kg/mm3 and a cured product compression strength of >=50 N/mm2. When the concrete having the maximum size of >40 mm is used, the strength of the concrete is controlled by forming test pieces from 40 mm-sieved concrete. The binder includes various Portland cements and mixed cements mixed with blast furnace slag and flied ash. In order to enhance the strength of the concrete, 2 to 15 wt.% of II type anhydrous gypsum or 2 to 20 wt.% of a silica-containing substance is added to the binder. On the production of the recycling concrete, the maximum diameter of virgin aggregate is desirably >=25 mm, more desirably >=40 mm.