纤维增强微膨胀湿接缝混凝土的性能研究

Study on the Properties of Fiber Reinforced Micro-expansion Wet Joint Concrete

研究了钢纤维、新型镁质膨胀剂(MEA)及其复合对湿接缝混凝土性能的影响。采用体视显微镜观察混凝土中钢纤维与基体之间的界面结构,利用压汞法测定混凝土中砂浆的孔结构。结果表明:MEA的掺入有利于补偿混凝土的收缩。随着钢纤维掺量的增加,膨胀混凝土的膨胀率呈下降趋势。钢纤维与MEA复合能有效改善混凝土的体积变形。钢纤维与MEA复合协同效应改善了混凝土的微结构,提高了基体及钢纤维与基体之间的密实程度,增加了基体对钢纤维的握裹力,更有利于改善湿接缝混凝土的力学性能和渗透性能。

The effects of steel fiber,Mg O-type expansive agent（MEA） and their composite on the performance of wet joint concrete were studied. The interface structure between steel fiber and matrix in concrete was observed by stereoscopic microscope,and the pore structure of mortar in concrete was measured by mercury pressure method. The results show that the incorporation of MEA is favorable for compensating the shrinkage of concrete. With the increase of steel fiber content,the expansion rate of expansive concrete is decreasing. Steel fiber and MEA composite can effectively improve the volume deformation of concrete. The synergistic effect of steel fiber and MEA improves the micro-structure of concrete,increases the density of matrix and between steel fiber and matrix,and enhances the bonding force of the matrix to steel fiber,which is more conducive to improving the mechanical and permeability of wet joint concrete.