Method for manufacturing concrete

摘要

The present invention is directed to a method for manufacturing a concrete which comprises the steps of mixing 20 to 100% of the total weight of cement used with water in an amount of 20 to 50% of this cement weight in order to prepare a stiff-consistency cement paste, afterward mixing the thus prepared cement paste with a coarse aggregate, further mixing 80 to 0% of the total amount of the cement and sand therewith in the order of the cement and the sand or at one time, and then mixing therewith the remaining water necessary to harden the total cement; or the present invention is directed to a method for manufacturing a concrete which comprises the steps of mixing 20 to 100% of the total weight of cement used with water in an amount of 20 to 50% of this cement weight and a coarse aggregate, so that a stiff-consistency cement paste is caused to adhere to the coarse aggregate, afterward mixing 80 to 0% of the total weight of cement and sand therewith in the order of the cement and the sand or at one time, and further mixing therewith the remaining water necessary to harden the total cement.