机制砂颗粒级配对砌筑干混砂浆力学性能的影响

Influence of grain grading of manufactured-sand on mechanical behaviors of dry-mixed mortar

目前,对干混砂浆的研究主要集中在天然砂配制的干混砂浆的品种和性能上,对机制砂干混砂浆的研究还很少.针对机制砂在生产过程中颗粒级配的可控优势,研究了8种不同粒组含量的机制砂对干混砂浆力学性能的影响.试验结果表明,砂浆的稠度值随石粉含量的减小呈现逐渐增大的趋势,其中石粉含量小于20％时砂浆的稠度值较好.砂浆的抗压和抗折强度值随石粉含量的减小及较大颗粒含量的增加呈现逐渐减小的趋势.砂浆的压折比总体上呈下降趋势,石粉含量小于20％时砂浆的压折比小于等于3,说明砂浆的柔韧性较好.砂浆与聚苯板和瓷砖的黏结强度随石粉含量的减小总体上呈先增大后减小趋势,石粉含量为5％到20％时砂浆的黏结强度值较高.因此,机制砂颗粒级配在石粉含量为15％ ～ 20％时,粒组所配砂浆的总体性能优良.

With the development of modern construction industry and people＇s growing concern on the living en- vironment, dry-mixed mortar has been rapidly developed due to the promoting of national policy. People＇s re- search on the dry-mixed mortar mainly focused on the varieties and properties of dry-mixed mortar with natural sand, and a little researches on dry-mixed mortar with manufactured-sand were carried out. Eight groups（ 1 ~ 8） of different particle sizes grading of manufactured-sands for dry-mixed mortars were investigated, in order to know the influence of the grain grading of manufactured-sands on the mechanical behaviors of dry-mixed mor- tar. The test results showed that the consistency of dry-mixed mortar increased with the decreasing of stone power content and the consistency were more appropriate as the stone power content at 5% -20%. The com- pressive strength and flexural strength of dry-mixed mortar decreased and the ratio of compressive strength to flexural strength decreased too, when the stone power content decreased and the flexibility were better as the stone power content less than 20% than other groups. The bonding strength of the mortar to polystyrene and ceramic tile first increased and then decreased and the bonding strength was bigger as the stone power content at 5% -20% than other groups. Thusly, the overall performances of dry-mixed mortars with manufactured-sands were good as the stone power content at 15% -20%.