低钙粉煤灰掺量、水胶比和养护龄期对混凝土抗压强度的影响  

INFLUENCE OF LOW-CALCIUM FLY ASH CONTENT,WATER-BINDER RATIO AND CURING AGE ON COMPRESSIVE STRENGTH OF CONCRETE

作　　者：张扬[1] 胥青柏 翟凯胜 景延会 ZHANG Yang;XU Qing-bai;ZHAI Kai-sheng;JING Yan-hui(School of Civil Engineering,Nanyang Institute of Technology,Nanyang 473000,China)

机构地区：[1]南阳理工学院土木工程学院,河南南阳473000

出　　处：《南阳理工学院学报》2022年第2期76-81,共6页Journal of Nanyang Institute of Technology

基　　金：博士科研启动项目(510093)。

摘　　要：本文对低钙粉煤灰掺量(0%、50%、70%、90%)、水胶比(0.38、0.44、0.50)和养护龄期(7 d、14 d、28 d)对混凝土抗压强度的影响进行了试验研究,并对试验结果进行了考虑交互作用的方差分析和回归分析,得到与试验结果吻合较好的经验公式,有一定工程参考价值。研究结果表明,低钙粉煤灰掺量、水胶比、养护龄期各因素单独对混凝土强度都有显著的影响,且双因素交互对混凝土强度也有显著的影响。掺加大量低钙粉煤灰可以减慢混凝土前7 d的强度增长,8~28 d强度增速下降也更平缓,强度发展的时间效应更显著;增大水胶比将减缓高掺量低钙粉煤灰混凝土在前7 d的强度增长,8~28 d强度增速下降也更急剧些;高掺量低钙粉煤灰混凝土抗压强度随着低钙粉煤灰掺量和水胶比的增大而减小,水胶比取0.38的70%低钙粉煤灰掺量混凝土的28 d抗压强度能达到C20以上,能够满足工程应用的需要。In this paper,the effect of low-calcium fly ash content(0%,50%,70%,90%),water-binder ratio(0.38,0.44,0.50)and curing age(7 d,14 d,28 d)on the concrete compressive strength was studied experimentally.The experimental results were analyzed by variance analysis and regression analysis considering the interaction,and an empirical formula that was in good agreement with the experimental results was obtained,which has a certain engineering reference value.The results of the study show that the low-calcium fly ash content,water-binder ratio,and curing age all have a significant impact on the strength of concrete,and the interaction of the two factors also has a significant impact on the strength of concrete.Adding a large amount of low-calcium fly ash into concrete will slow down the strength growth of concrete in the first 7 days,and the strength growth rate from day 8 to day 28 will decrease more slowly,and the time effect of strength development will be more significant.Increasing the water-binder ratio of high-content low-calcium fly ash concrete will slow down the strength growth in the first 7 days,and the strength growth rate from day 8 to day 28 will decrease more sharply.The compressive strength of high-content low-calcium fly ash concrete will decrease with the increase of low-calcium fly ash content and water-binder ratio.The 28 d compressive strength of concrete with a low-calcium fly ash content of 70%and a water-binder ratio of 0.38 can reach C20 or more,which can meet the needs of engineering applications.

关 键 词：高掺量低钙粉煤灰混凝土 抗压强度 低钙粉煤灰掺量 水胶比 养护龄期 方差分析 回归分析 

分 类 号：TU528[建筑科学—建筑技术科学]