改性脱硫石膏基混凝土物理力学性能试验研究

Experimental Study on Physical and Mechanical Properties of Modified desulfurization Gypsum-based Concrete

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。

In order to verify the feasibility of replacing cement witli modified desulphurization gypsum the ex-perimental metliod was used to study the physical and mechanical properties of the modified desulfurization gysum and cement and its concrete was carried out. The results showthat the compressive strength of the modified desul-phurization gypsum-based concrete is 44 MPa, the flexural strength reaches 9.5 MPa, which is hihger than that of cement-based concrete and the tensile strength and shear strength are close to that of cement-based concrete, so it is feasible to replace cement as cementitious material. The difference of curing condition will influence the gtowth of concrete strength, and the curing condition of low humidity is more suitable for the development of the later strength of the modified desulfurization gypsum-based concrete. Therefore, in the coal mine tunnel shotcrete support con-struction need not sprinkle the water maintenance, thus reduces the construction procedure, enhances the construc-tion eficiency. 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.