(西安科技大学地质与环境学院, 西安 710054)

摘要: 使用破碎、筛分后的废弃石屑代替石英砂作为骨料制备超高性能混凝土(UHPC). 基于单因素分析试验,研究了各因素(水胶比、胶集比、减水剂掺量、钢纤维掺量)对石屑 UHPC 抗压强度、抗折强度及流动度的影响规律,考查了四种不同养生方式下石屑 UHPC 力学性能的变化. 结果表明,当胶集比、水胶比、减水剂掺量、钢纤维掺量分别为 0. 63、0. 2、2. 1%和 1. 5%时,石屑 UHPC 的力学性能和工作性能最优,7d 抗压强度最高为 113. 7MPa,抗折强度为 35. 2MPa;分析应力-应变曲线发现,掺加钢纤维不仅可以提高石屑 UHPC 的力学强度,还能显著提高石屑UHPC 的韧性和残余抗压强度;经过水浴养护、干热养护和水浴+干热组合养护后,石屑 UHPC 的抗压强度分别提高了 5. 7%、27. 1%和 40. 3%,但热养护对抗折强度影响不大.

关键词: 超高性能混凝土; 石屑; 力学强度; 流动度; 养生方式

中图分类号:TU528. 31 文献标志码:A 文章编号:1002-848X(2023)05-0058-05

DOI:10. 19701 / j. jzjg. 20201434

Experimental study on mechanical properties of UHPC prepared by stone chips

ZHAI Xueqiang, LI Xiaojun

(College of Geology and Environment, Xi􀆳an University of Science and Technology, Xi􀆳an 710054, China)

Abstract: Use sieved granite chips to completely replace quartz sand as aggregate to prepare ultra high performance concrete(UHPC). Based on the single factor analysis test, the influence of various factors ( binder-aggregate ratio, water-binderratio, water reducing agent content, steel fiber content) on the stone chip UHPC compressive strength, flexural strength andliquidity was studied, and examined the changes in the mechanical properties of stone chip UHPC under four different curingmethods were presented. The results show that when the binder-aggregate ratio, water-binder ratio, water reducing agentcontent, and steel fiber content are 0. 63, 0. 2, 2. 1% and 1. 5% respectively, the mechanical properties and workingperformance of stone chip UHPC are best, the 7d compressive strength is 113. 7MPa, and the flexural strength is 35. 2MPa.Analysis of the stress-strain curve found that the addition of steel fiber can not only improve the mechanical strength of stonechip UHPC, but also significantly improve the toughness and residual compressive strength of stone chip UHPC. After waterbath curing, dry heat curing and water bath + dry heat curing, the compressive strength of stone chip UHPC increased by5. 7%, 27. 1% and 40. 3% respectively, but thermal curing have little effect on the flexural strength.

Keywords:ultra high performance concrete; stone chip; mechanical strength; liquidity; curing method

∗陕西省土地工程建设集团科研项目(DJNY2019-10).

第一作者:翟雪强,硕士,主要从事固废再生利用研究,Email:1944116417@ qq. com.

[引用本文] 翟雪强,李晓军. 石屑制备超高性能混凝土力学性能试验研究[ J]. 建筑结构,2023,53( 5):58-62.ZHAI Xueqiang,LI Xiaojun. Experimental study on mechanical properties of UHPC prepared by stone chips[J]. BuildingStructure,2023,53(5):58-62.