硼酸对硫铝酸盐基复合胶凝材料性能的影响

Effect of Boric Acid on Properties of Sulphoaluminate Based Composite Cementitious Materials

本文研究了不同硼酸掺量下的硫铝酸盐基复合胶凝材料的标准稠度用水量和凝结时间及安定性,抗压、抗折强度变化规律,并利用XRD和SEM测试方法对复合胶凝材料的水化机理进行分析。结果表明:硼酸的掺入不影响胶凝材料的安定性,但使标准稠度用水量增加,且标准稠度用水量与硼酸掺量成反比;硼酸掺量越大,初、终凝时间延长越明显;当硼酸掺量为0.20%(质量分数)时,硫铝酸盐水泥占比高的试验组早期强度提高,且后期强度不倒缩;硼酸可使钙矾石的形态更粗壮。掺加硼酸可使复合材料的干缩率降低,质量变化率呈下降趋势。

In this paper,the standard consistency water consumption,setting time,stability and the change law of compressive and flexural strength of sulfoaluminate based composite cementitious materials with different boric acid amounts were studied,and the hydration mechanism of composite cementitious materials was analyzed by XRD and SEM.The results show that the incorporation of boric acid does not affect the stability of cementitious materials,its standard consistency water consumption increases,and the standard consistency water consumption is inversely proportional to the amount of boric acid.The greater the amount of boric acid is,the more obvious the prolongation of the initial and final setting time is.When the amount of boric acid is 0.20%(mass fraction),the early strength of the test group with a high proportion of sulfoaluminate cement increases,and the late strength can not be inverted shrinkage.Boric acid can make the morphology of AFt stouter.The doping of boric acid can make the dry shrinkage rate decrease and the quality change rate show a decreasing trend.