摘要
为了合理有效地确定钢纤维自密实混凝土配合比设计中水胶比和矿渣粉、粉煤灰及钢纤维掺量,进行了多项性能指标的"5因素4水平"正交试验,分析了各因素水平对钢纤维自密实混凝土的填充性、间隙通过性及抗离析性的影响,确定了各因素最优组合方案并进行了试验验证。结果表明:①随着水胶比的增加,钢纤维自密实混凝土的填充性、间隙通过性均呈现先增加后减小的变化趋势;当水胶比达到0.31后继续增加水胶比,拌合物的离析率会急剧增加。②钢纤维掺量的变化对拌合物填充性和间隙通过性的影响可作为误差因素不做考虑;综合考虑混凝土的抗离析性,钢纤维掺量为40 kg/m^3时即起到了连接作用,又充当了填料,抗离析性最佳。③各因素水平最佳组合为水胶比0.31、钢纤维掺量40 kg/m^3、矿渣粉掺量20%、粉煤灰掺量10%。④28 d劈裂强度提高了22.2%,满足钢混结合段特殊条件下的施工技术要求。
In order to determine the water-cement ratio and the quantity of slag powder,fly ash and steel fiber reasonably and effectively in the steel fiber reinforced self-compacting concrete mixture ratio design,the orthogonal experiment of "5 factors and 4 levels" with many performance index have been done just to analyze the effects of various factors on the filling in the gaps of the steel fiber reinforced self-compacting concrete,the effects of flowing through the gaps of reinforcement and segregation resistance,and the optimal combination scheme of several factors was determined and test verification have been conducted. The results show:with the increase of water-cement ratio,the filling in the gaps of the steel fiber reinforced self-compacting concrete and the gap passability presents the change trend of increasing first and then decreasing,and when the water-cement ratio reaches 0.31 and continues to increase,the segregation rate of mixture will increase sharply;the influence of the change of steel fiber content on the filling property and gap passability of the mixture can be considered as the error factor;according to the comprehensive consider on the segregation resistance of concrete,when steel fiber content is 40 kg/m^3,it plays an important role in connecting and acts as a filler,and the segregation resistance effect is best;the best combination of each factor has been listed as follows:water-cement ratio of 0.31,steel fiber content of 40 kg/m^3,slag powder content of 20% and fly ash content of 10%;the cleavage strength of 28 d has increased by 22.2%,which meets the construction technique requirements under special conditions of steel-concrete combination section.
作者
周世康
谢生华
康梦安
ZHOU Shikang;XIE Shenghua;KANG Meng′an(CCCC First Highway Xiamen Engineering Co.,Ltd.,Xiamen 361000,China;CCCC First Highway Xiamen Testing Technology Co.,Ltd.,Xiamen 361021,China)
出处
《华北水利水电大学学报(自然科学版)》
2019年第2期70-76,共7页
Journal of North China University of Water Resources and Electric Power:Natural Science Edition
关键词
钢纤维
自密实混凝土
正交试验
配合比设计
steel fiber
self-compacting concrete
orthogonal experiment
mix design