Abstract: The present invention provides a producing method of concrete capable of appropriately controlling setting and hardening, and having excellent flexibility of production and handling of concrete. The producing method of concrete includes a cement paste mixing step and a concrete mixing step. In the cement paste mixing step, cement, mixing water and retarder are mixed together to obtain cement paste. According to this, setting and hardening of the cement paste are suppressed, and it is possible to store the cement paste for predetermined time. In the concrete mixing step, aggregate is input into the cement paste, and they are mixed together to obtain concrete. By the mixing operation, a setting-delaying effect is canceled.

Abstract: The present invention provides a producing method of concrete capable of appropriately controlling setting and hardening, and having excellent flexibility of production and handling of concrete. The producing method of concrete includes a cement paste mixing step and a concrete mixing step. In the cement paste mixing step, cement, mixing water and retarder are mixed together to obtain cement paste. According to this, setting and hardening of the cement paste are suppressed, and it is possible to store the cement paste for predetermined time. In the concrete mixing step, aggregate is input into the cement paste, and they are mixed together to obtain concrete. By the mixing operation, a setting-delaying effect is canceled.