摘要
通过对强度等级从C60~C100的高性能隧道喷射混凝土配合比试验数据的非线性回归,构建出了高性能混凝土28 d抗压强度的预报式,结果表明:水胶比与混凝土强度间为中度负线性关系,水胶比、坍落度间为中度正线性相关。得出了砂率、水胶比、聚羧酸类减水剂、硅灰用量及粉煤灰对砂率的影响:水胶比以0.21~0.32为宜;砂率应控制在29%~41%;聚羧酸系高效减水剂掺量控制在1.49%~2.48%;硅灰掺量控制在5%~10%;粉煤灰掺量控制在21.5%~31.5%。混凝土渗透性能在水灰比越低时越差;硅灰和粉煤灰在改善高性能混凝土渗透性方面起到了很大作用。13号的配制比例,在整冻融循环过程中,试件质量保持稳定,在75次循环时,有0.57%的增大,完成整个冻融试验仅有0.02%,该配合比抗冻性能满足要求。随着冻融次数增加,配合比混凝土抗压强度逐渐降低。在冻融次数为300次时,编号13、编号5、编号9的抗压强度降低幅度分别为12.3%、24.0%、21.7%,表明粉煤灰加入后,试件抗冻性能降低。
The 28 d compressive strength prediction equation of high-performance concrete is established by nonlinear regression of high-performance concrete with strength grade from C60 to C100 to nonlinear regression of high-performance tunnel shotcrete mix ratio test data,and the results show that there is a moderate negative linear relationship between the water-adhesive ratio and concrete strength,and a moderate positive linear correlation between the water-adhesive ratio and slump.The best value range of sand rate,water-to-adhesive ratio,polycarboxylic acid-based high-efficiency water reducing agent,silica ash dosage and fly ash can be obtained:the water-to-adhesive ratio is controlled between 0.21 and 0.32.The sand rate should be controlled between 29% and 41%.The content of polycarboxylic acid-based high-efficiency water reducing agent is controlled within from 1.49%to 2.48%.Silica ash:its content is controlled within from 5% to 10%.The fly ash content is controlled at from 21.5% to 31.5%.The permeability of concrete is worse when the water-cement ratio is lower;Silica ash and fly ash have an important impact on the improvement of the permeability of high-performance concrete.The mix ratio of No.13,in the process of freeze-thaw cycle,the quality of the specimen remains stable,at 75 cycles,there is an increase of 0.57%,and the completion of the entire freeze-thaw test is only 0.02%,the antifreeze performance of this ratio meets the requirements.With the increase of freeze-thaw times,the compressive strength of the concrete gradually decreases.When the number of freeze-thaw times was 300 times,the compressive strength of No.13,No.5 and No.9 decreased by 12.3%,24.0% and 21.7%,respectively,indicating that the frost resistance of the specimen was reduced after the fly ash was added.
作者
韩向明
韩鹏举
马富丽
HAN Xiangming;HAN Pengju;MA Fuli(School of Architectural Engineering,Shanxi Vocational University of Engineering Scienceand Technology,Taiyuan 030000,China;School of Civil Engineering,Taiyuan University of Technology,Taiyuan 030000,China)
出处
《混凝土》
北大核心
2024年第12期153-156,169,共5页
Concrete
基金
山西省自然科学基金“赤泥-煤系偏高岭土基地聚合物混凝土的长期工作性能及其机理研究”(20210302124613)。
关键词
高性能混凝土
喷射混凝土
配合比
抗冻性能
high-performance concrete
shotcrete
mix ratio
antifreeze properties
作者简介
第一作者:韩向明(1982-),男,硕士,副教授,研究方向:建筑与土木工程、建筑工程管理。联系地址:L山西省晋中市榆次区大学城文华街369号(030000),联系电话:13633453177。
