超细矿粉对复合水泥砂浆性能的影响

Effect of ultrafine mineral powder on the properties of cementitious materials

文章采用4种细度的超细矿粉,以6种比例取代水泥,设计2组试验配合比,研究超细矿粉取代率和细度对复合水泥砂浆的工作性能和力学性能的影响。结果表明,矿粉的加入降低了水泥砂浆的流动度,流动度随着取代率的增加而降低,随着细度的增大逐渐增大;对于600目矿粉,随着矿粉取代率的增加,复合水泥砂浆的3d、7d抗压强度均逐步降低,但28d强度先增高后降低,在取代率为30%时强度最高;对于超细矿粉30%取代水泥,复合水泥砂浆的早期抗压强度均低于纯水泥砂浆,但后期抗压强度发展迅速,28d强度均高于纯水泥砂浆,且细度越大,强度越高。

This paper uses four different finenesses of ultrafine mineral powder and replaces the cement with six different proportions,and two sets of test ratios were designed for the test,and the effects of different replacement rates and different finenesses of ultrafine mineral powder replacing the same mass of cement on the workability and mechanical properties of composite cement mortar were studied.The results show that:the addition of mineral powder reduces the flow of cement mortar,the flow of composite cement mortar decreases with the increase of mineral powder substitution rate,and gradually increases with the increase of mineral powder fineness;for 600 mesh mineral powder,with the increase of mineral powder substitution rate,the 3d and 7d compressive strength of composite cement mortar are gradually reduced,but the 28d strength increases first and then decreases,of which the highest strength is at 30%substitution rate;for the early compressive strength of composite cement mortar is lower than that of pure cement mortar with 30%replacement of superfine mineral powder with the same quality of cement,but the later compressive strength develops rapidly and the 28d strength is higher than that of pure cement mortar,and the greater the fineness,the higher the strength.