Capability Of Resisting Sulfate Corrode And Strength Of Sulphoaluminate Cement Concrete

In order to solve the concrete engineering problems which have requirements of rapid hardening, early strength and high resistance to sulfate attack in the saline areas of Xinjiang, The measures to control setting time and the strength characteristics of Sulphoaluminate cement concrete conserved under20℃、0℃、-15℃in the case that the water cement ratio are0.5,0.4and0.3were studied. We also took macroscopic observation and microscopic observation methods of scanning electron microscope (SEM) and energy dispersion spectrum (EDS) to analysis and reveal the anti-erosion mechanism of SAC. The found in the research are as follows:(1) Both boric acid retarder and FND superplasticize are adapt well to sulphoaluminate cement. The setting time of sulphoaluminate concrete can reach at6h to8h as the volume of boric acid retarder control at0.125%to0.2%. The volume of boric acid retarder will not affect the saturation output of FND superplasticizer. Only do the experiment of the binary system of "cement+retarder" can chose the dosage of superplasticizer saturation.(2) Water cement ratio and curing temperature are the main influence factors of sulphoaluminate cement concrete strength. With the water-cement ratio reduced and curing temperature increased, the Strength of sulphoaluminate cement concrete will be increased. Based on Standard design age for3d and under standard curing(20℃),the sulphoaluminate cement concrete that strength grade form C10to C55can be made in the case that the water cement ratio are form0.3to0.5.And the Strength for1d can reach at75%to85%of the Strength for3d. It’s indicated that the Sulphoaluminate concrete has early strength characteristics. The construction period of concrete can shorten greatly by using of sulphoaluminate concrete.(3) Taking the method of adding small amount of antifreeze and auxiliary insulation measures, the sulphoaluminate concrete still has a rapid hardening and early strength performance, and its strength can be developed well. It’s show that the sulphoaluminate concrete has good negative temperature performance. The year construction period in northwest alpine arid regions can be extended greatly by using of sulphoaluminate cement concrete.(4) The capability of resisting sulfate corrode of sulphoaluminate cement concrete is significantly higher than that of the high sulfur resistant cement. Even though the sulphoaluminate cement concrete suffered sulfate attack immediately after formwork, it still can resist sulfate solution for20250mg/l. With the water-cement ratio reduced and curing period extended, the capability of resisting sulfate corrode of sulphoaluminate cement concrete can be further improved. It’s indicated that sulphoaluminate cement concrete can solve the concrete engineering problems which have requirements of rapid hardening, early strength and high resistance to sulfate attack in the northwest alpine arid areas and saline areas.(5) The high sulfate resistance ability of sulphoaluminate cement concrete mainly depends on its high density and the chemical erosion due reduced.