STRENGTHENING OF HYDROTHERMAL HOT-PRESSED CONCRETE WASTES BY THE ADDITION OF FRESH CEMENT

In order to recycle concrete wastes, a new processing method for solid ifying pulverized concrete wastes has been developed using a hydrother mal hot-pressing method. The effect of addition of fresh cement was ex amined to further increase the strength of solidified concrete wastes, Hydrothermal hot-pressing tests were carried out at 200-250 degrees C with the water content of 10-30 mass% under the pressure of 20 MPa fo r 20 min. Fresh cement of 0-50 mass% was added to the mixture. It is s hown that the formation of tobermorite improved the tensile strength. The tensile strength determined by a Brazilian test reached approximat ely 13 MPa under the conditions; the temperature:230 degrees C, fresh cement content :50 mass%, and water content:30 mass%.