改性脱硫石膏基混凝土物理力学性能试验研究

为了验证改性脱硫石膏替代水泥的可行性,采用实验方法,对改性脱硫石膏和水泥及其混凝土的物理力学性能进行了对比试验研究。结果表明:改性脱硫石膏基混凝土抗压强度达到44 MPa,抗折强度达到9.5 MPa,明显高于水泥基混凝土。抗拉强度、抗剪强度与水泥基混凝土较为接近;因此,改性脱硫石膏替代水泥作为胶凝材料是可行的。养护条件的差异会对混凝土强度增长产生影响,低湿度的常温养护条件更适宜改性脱硫石膏基混凝土后期强度的发展;所以在煤矿巷道的喷射混凝土支护施工后无需洒水养护,从而减少施工工序,提高施工效率。另外,还给出了改性脱硫石膏基喷射混凝土配合比的三种优化方案,在满足其施工所需强度的条件下能够方便灵活地选用其最优配合比。

Experimental study on physical and mechanical properties of modified gypsum - based concrete

In order to verify the feasibility of modified gypsum instead of cement, the experimental method was used to study the physical and mechanical properties of modified gypsum and cement and their corresponding concrete. The results show that the compressive strength, rupture strength, tensile strength and shear strength of the modified gypsum-based concrete are higher than those of the cement-based concrete for mine. The coefficient of water absorption of the modified gypsum-based concrete is large, and its softening coefficiency is the same in the early stage. But the softening coefficient of the two kinds of concrete materials is basically equal after 14 days. Therefore, the modified desulfurization gypsum instead of cement as a cementitious material is feasible, and in the coal mine roadway after the shotcrete support construction without water conservation, thereby reducing the construction process and improve the construction efficiency. In addition, three optimization schemes about the proportion of mixture of modified desulfurization gypsum-based shotcrete are given, and the optimal proportion of mixture can be selected flexibly and conveniently under the condition of the required strength of the construction.