Plastic Shrinkage Evaluation of Self-Consolidating Concrete as Repair Materials Based on Restrained and Free Strain Measurements
Plastic Shrinkage Evaluation of Self-Consolidating Concrete as Repair Materials Based on Restrained and Free Strain Measurements
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基于约束和自由应变测量的自密实混凝土作为修复材料的塑性收缩评估
DOI：
10.1007/978-90-481-9664-7_25
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
A. Javid
中科院分区：
文献类型：
--
作者：
P. Ghoddousi;A. Javid
维修工程师可能面临的最具挑战性的问题之一是，完成的结构是一个没有裂缝的整体，特别是关于混凝土平台的塑性收缩裂缝。基体表面粗糙度越大，基体与修补层之间的结合强度越大。但同时，粗糙度越大，加铺层约束越大，在收缩过程中，修补材料中会产生拉应力。本文报道的调查结果涉及的效果的类型的修补材料的自由和限制塑性收缩性能。在这项工作中使用的四种类型的修补材料是平面自密实混凝土（SCC），SCC含有硅灰（SF），SCC含有SF和胶乳（丁苯橡胶），SCC含有SF，胶乳，和纤维。为了使基底的表面粗糙化，使用凹痕来提供约束。这些板经受风、温度和相对湿度的严重组合。测试程序包括：沉降应变、自由和约束收缩应变、蒸发和泌水速率以及裂缝特性测量。结果表明，虽然蒸发率和泌水率对收缩率有影响，但其他因素如纤维类型、粘合剂类型和胶乳的使用对收缩率的影响较小。结果表明，与胶乳和纤维表现出最低的塑性沉降和收缩应变，以及裂缝面积和最长的时间，以首次开裂的SCC观察到显着的改善。平面自密实混凝土的沉降和收缩应变几乎是乳胶和纤维自密实混凝土的两倍。
One of the most challenging problems that can confront a repair engineer is that the completed structure is a monolithic mass that is free from cracks, especially with regard to the plastic shrinkage cracking in concrete flatwork. The more roughness in the surface of substrate, there will be more bond strength between substrate and repair overlay. But, meanwhile, the more roughness, more restraints induced in overlay, which during shrinkage, tensile stresses will be generated in repair materials. The results of investigation reported herein concern the effect of the type of repair materials on free and restrained plastic shrinkage properties. Four types of repair materials were used in this work are plane self-consolidating concrete (SCC), SCC containing silica fume (SF), SCC containing SF and latex (Styrene Butadiene Rubber), and SCC containing SF, latex, and fiber. To roughen the surface of substrate base, dents were used to provide restraints. The panels were subjected to severe combination of wind, temperature, and relative humidity. The test program includes: settlement strain, free and restrained shrinkage strain, evaporation and bleeding rates, and crack characteristic measurements. The results show that, while the rates of evaporation and bleeding affect shrinkage, it is over shadowed by other factors, such as fiber type, binder type and use of latex. The results show that, a significant improvement was observed for SCC with latex and fiber exhibiting the lowest plastic settlement and shrinkage strains, as well as crack area and longest time to first cracking. The plane SCC exhibited almost twice the settlement and shrinkage strains than SCC with latex and fiber.