Use of High-Range Retarder-Plasticizer for Roller-Compacted Concrete of the Three Gorges Project in China

Abstract

Polybasic organic phosphate and lignosulphonate were combined in appropriate proportions to be a kind of high-range retarder-plasticizer (KM) for use in higher temperatures. Various retarders have been used in ordinary concrete and roller-compacted concrete (RCC) for testing under 45(C) degrees and 25% relative humidity. Rheology and time of setting for fresh concrete and mechanical properties of hardened concrete, allowance of exposure time of bond between two construction layers of RCC, etc. were investigated. Simulated testing for Three Gorges Project was also carried out by testing at the Development General Co. and the Testing Center of Gezhouba group.