三峡工程混凝土掺高效减水剂与引气剂复合试验研究

采用葛洲坝水泥厂生产的525中热硅酸盐水泥、425低热矿渣硅酸盐水泥,平圩电厂Ⅰ级粉煤灰及花岗岩人工砂石料,进行了掺ZB-1A,ZB-1,FDN9001及R561C 4种缓凝高效减水剂,PC-2、文松及CJ4 3种引气剂共计24个配合比的新拌混凝土坍落度、含气量、泌水率、凝结时间试验,并对硬化混凝土进行了抗压强度及抗冻性能试验.试验结果表明:使用中热水泥的混凝土单位用水量要低于低热水泥,抗冻性能也优于低热水泥,但使用低热水泥配制大坝内部混凝土仍可满足D100～D150的抗冻要求.几种减水剂与引气剂复合时,其抗冻性能有差异,但均可满足D250～D300(中热水泥)及D100～D150(低热水泥)的抗冻技术要求.

Test on compound concrete of Three Gorges Project with high efficiency water-reducing agent and air-entraining admixture

The materials used for studying TGP concrete were moderate heat cement abelled 525 and low heat cement labelled 425 produced by Gezhouba Cenment Plant, fly ash of Pingwei Power Plant and aggregate of crushed granite, as well as several kinds of admixture including four kinds of high efficiency retarding water reducing agents (ZB 1A,AB 1,FDN9001 and R561C) and three kinds of air entraining admixtures(PC 2,Wensong and CJ4). Fresh placed concretes designed by Tweenty four sets of mix proportions in total were tested. The properties of fresh concrete such as slump constant, air content, bleeding rate and different setting time, and the compressive strength and frost resistance of hardened concrete were studied. The results show that the unit water use of concrete with moderate heat cement is lower than that with low head cement and the frost resistance property of the former is better than that of the latter, which still satisfies with requirements of D100 D150. The frost resistance property of concrete will be different with different compounds of water reducer and air entraining admixture, but all of them can meet the corresponding technical requirements of D250 D300(for) moderate heat cement) or D100 D150(for low heat cement).