碳酸钙晶须对脱硫石膏基复合胶凝材料性能的影响

Effect of calcium carbonate whisker on properties of desulfurized gypsum-based composite cementitious material

在脱硫石膏基复合胶凝材料(DGCM)中加入不同掺量的碳酸钙晶须,探究了碳酸钙晶须对DGCM的力学性能、耐水性能及耐候性能的影响,并从微观角度揭示碳酸钙晶须的作用机理。结果表明,掺入碳酸钙晶须可以有效改善DGCM的力学性能,随着晶须掺量的增加,硬化体7 d与28 d的绝干抗压强度先缓慢上升后下降又逐渐上升,而绝干抗折强度呈现波动状态;掺入碳酸钙晶须对DGCM耐水性能的提升效果不明显,当掺量大于1%后,大多数试样的吸水率都较空白组有所上升,而软化系数有所下降;碳酸钙晶须有助于提升DGCM的耐干湿性能和耐冻融性能,当掺量为1%时,基体的干湿循环溶蚀率最小达到0.22%,冻融循环强度系数最大达到0.75,试件的耐候性能较好。

Adding different amounts of calcium carbonate whiskers to desulfurization gypsum based composite cementitious material(DGCM),the effect of calcium carbonate whiskers on the mechanical properties,water resistance,and durability of DGCM was investigated,and the mechanism of calcium carbonate whiskers was revealed from a microscopic perspective.The result shows that adding calcium carbonate whiskers can effectively improve the mechanical properties of DGCM.With the increase of whisker content,the absolute dry compressive strength of hardened bodies at 7 d and 28 d first slowly increases,then decreases,and then gradually increases,while the absolute dry flexural strength presents a fluctuating state;the effect of adding calcium carbonate whiskers on improving the water resistance of DGCM is not significant,when the dosage is greater than 1%,the water absorption of most samples increased compared to the blank group,while the softening coefficient decreased;calcium carbonate whiskers help to improve the dry and wet resistance and freeze thaw resistance of DGCM.When the content is 1%,the minimum dry and wet cyclic corrosion rate of the substrate reaches 0.22%,while the maximum freeze thaw strength coefficient at this time reaches 0.75,indicating a good durability of the test piece.