不同岩性石粉-水泥复合胶凝材料性能研究

Study on Properties of Different Lithology Stone Powder-Cement Composite Cementitious Materials

为探明石灰岩、花岗岩、石英岩和凝灰岩石粉用作混凝土矿物掺合料的可行性,采用X射线衍射仪、Zeta电位仪和总有机碳分析仪分别测定了不同岩性石粉的矿物组成、Zeta电位和减水剂吸附率,研究了石粉-水泥二元复合胶凝材料和石粉-粉煤灰/矿渣粉-水泥三元复合胶凝材料净浆和胶砂的工作性能和力学性能。结果表明:石粉的矿物组成对Zeta电位和减水剂吸附率影响较大,沸石矿物疏松结构使凝灰岩石粉的Zeta电位和减水剂吸附作用随时间变化明显,云母矿物的插层吸附使花岗岩石粉对减水剂的吸附作用明显。不同岩性石粉对复合胶凝材料浆体工作性能的影响与石粉对减水剂的吸附性能密切相关。不同岩性石粉-水泥复合胶凝材料胶砂的抗压强度比和抗折强度比均高于60%,且石粉增加了水泥胶砂的折压比,提高了胶砂试件的韧性。

In order to explore the feasibility of limestone,granite,quartzite and tuff powder as mineral admixture for concrete,the mineral composition,Zeta potential and superplasticizer adsorption rate of stone powder with different lithology were measured by the X-ray diffractometer,Zeta potential analyzer and total organic carbon analyzer.The workability and mechanical properties of the paste and mortar of stone powder-cement binary composite cementitious materials and stone powder-fly ash/slag powder-cement ternary composite cementitious materials were studied.The results show that the mineral composition of stone powder has great influence on Zeta potential and superplasticizer adsorption rate.Zeta potential and superplasticizer adsorption rate of tuff powder change obviously with the increase of time due to the loose structure of zeolite minerals.The intercalation adsorption of mica minerals makes the obvious superplasticizer adsorption of granite powder.The effect of different lithology stone powder on the workability of composite cementitious material paste is closely related to the superplasticizer adsorption of stone powder.The compressive strength ratio and bending strength ratio of different lithology stone powder-cement composite cementitious materials are all higher than 60%,and the stone powder increases the flexural pressure ratio of cement mortar and improves the toughness of the mortar specimen.