粗骨料对膏体泌水性及力学性能的影响
The effect of coarse aggregate on the bleeding and mechanical properties of cemented paste backfill
尹升华 1闫泽鹏1
作者信息
- 1. School of Civil and Resources Engineering,University of Science and Technology Beijing,Beijing 100083,China;University of Science and Technology Beijing,Beijing 100083,China
- 折叠
摘要
本文研究了骨料类型、粗骨料含量、质量浓度和灰砂比对膏体泌水率和力学性能的影响.用全尾砂代替河砂可以显著降低泌水率.尾矿的掺入使膏体的保水性提高了10％～20％,28 d后的无侧限抗压强度(UCS)提高了10％～30％.当粗骨料含量为60％时,泌水率对质量浓度的敏感性降低.可以看出,增加粗骨料含量是提高膏体流动性的一种方式.膏体的力学性能随粗骨料含量呈先增加后减小的趋势,当粗骨料含量为50％时,CPB强度最大可达6.5 MPa.膏体的力学性能随着质量浓度的增加而成比例增强,79％质量浓度的样品养护28 d后的UCS可达到7.9 MPa.灰砂比对力学性能影响较大,当灰砂比由1:6增加到1:4时,28 d后的UCS增加了54.4％,泌水率下降至1.4％.
Abstract
An experimental study is conducted to investigate the effect of different aggregate types, coarse aggregate content, mass concentration, and cement-sand ratio on the bleeding rate and mechanical properties of cemented paste backfill (CPB). Replacing river sand with unclassified tailing can significantly reduce the bleeding rate. The addition of fine-grained tailing increased the water retention of the mixture by 10％−20％ and the 28 d unconfined compressive strength (UCS) by 10％−30％. The sensitivity of the bleeding rate to mass concentration is reduced at 60％ coarse aggregate content. Increasing the coarse aggregate content is a way to improve the high-concentration CPB fluidity. There is a coarse aggregate optimal content to maximize the sample strength. Test results show that when the coarse aggregate content is 50％, the maximum CPB strength can reach 6.5 MPa. As the mass concentration increases, the mechanical properties increase proportionally. After curing 28 d, the UCS of the 79％ mass concentration sample reached 7.9 MPa. The cement-sand ratio had a greater effect on the mechanical properties, and when the cement-sand ratio increased from 1:6 to 1:4, the UCS at 28 d increased by 54.4％, and the bleeding rate decreased to 1.4％.
关键词
膏体充填/泌水率/粗骨料/力学性能Key words
cemented paste backfill/bleeding rate/coarse aggregate/mechanical properties引用本文复制引用
基金项目
Shandong Provincial Major Science and Technology Innovation Project,China(2019SDZY05)
Key Program of National Natural Science Foundation of China(51734001)
Fundamental Research Funds for the Central Universities,China(FRF-TP-18-003C1)
出版年
2023
NETL
NSTL
维普
万方数据