摘要
喷射混凝土经常存在回弹率大、施工损耗严重的问题。主要通过对喷射混凝土配合比进行优化,考虑水灰比、砂率和胶凝材料用量3个因素,设计了正交试验,考察了因素对喷射混凝土回弹率的影响规律。分析表明,喷射混凝土回弹率的最主要影响因素是砂率,其次是水灰比和胶凝材料用量。选出3个代表性配合比进行了现场试配和喷射施工,无论出机坍落度、扩展度、含气量等都能满足设计要求,拌合物状态较好,无泌浆抓底现象;放置1 h后坍落度损失很小;实测强度基本都能满足大于等于30 MPa的要求,正交试验中选出的最优配比现场回弹率最小。
Shotcrete often has the disadvantages of high rebound rate and serious construction loss.By optimizing the mix ratio of shotcrete,and considering the three factors of water-cement ratio,sand ratio and cementitious material content,this paper designs the orthogonal test to investigate the influence of the three factors on the rebound rate of shotcrete.The results show that:The most important factor influencing the rebound rate of shotcrete is the sand ratio,followed by the water-cement ratio and the cementitious material content.Three representative mix ratios are selected for on-site trial mixing and spray construction.All the slump,expansion degree,and air content of the shotcrete meet the design requirements.The state of the mixture is good,and there is no concrete disintegration.The slump loss is very small after being placed for 1 h;the measured strength generally is greater than 30 MPa;and the shotcrete with the optimal ratio selected in the orthogonal test has the smallest on-site rebound rate.
作者
杨永民
YANG Yongmin(Zhongkai University of Agriculture and Engineering,Guangzhou 510225,China;Institute of Sustainable Development of Building Energy Conservation,Zhongkai University of Agriculture and Engineering,Guangzhou 510225,China)
出处
《人民珠江》
2021年第2期57-60,共4页
Pearl River
基金
广东省水利科技创新项目(2016-15)。
