再生骨料表面残留附着砂浆含量统计

Statistical of adhered mortar on the surface of recycled aggregate

再生骨料表面残留的附着砂浆是再生骨料与天然骨料的主要区别,也是劣化其力学性能的根本原因。为了获得再生骨料表面残留的附着砂浆含量,建立了基于图像分析技术的附着砂浆含量统计方法,统计了不同粒径范围内的再生骨料表面附着砂浆含量,系统研究了再生骨料粒径对附着砂浆含量的影响,通过高温-低温循环试验处理同粒径范围的再生骨料,论证了图像分析方法的适用性和可行性。研究结果表明:图像分析方法是一种高效、安全的统计方法,可以用来统计再生骨料表面残留的附着砂浆含量;在骨料粒径为10.0~31.5 mm内,附着砂浆含量介于35.94%~38.99%;粒径为16.0~20.0 mm内的再生骨料表面残留附着砂浆含量最低,相对其他粒径具有较高的质量和性能;在设计再生混凝土配合比时,应适当增加该粒径范围内的再生骨料含量,以降低附着砂浆对再生混凝土力学性能的劣化影响。

The adhered mortar on the surface of recycled aggregate is the main difference between the recycled aggregates and natural aggregates,and is also the primary cause of deterioration of its mechanical properties.To obtain the content of adhered mortar on the surface ofrecycled aggregate,a statistical method of adhered mortar based on the image analysis was established,and the effect of recycled aggregate size on the content of adhered mortar was investigated.Thereafter,the cycle test of high-low temperature was conducted to demonstrate the applicability and feasibility of image analysis method.The research results shown that the image analysis method is an efficient and safe statistical method,which can be used to count the content of adhered mortar on the surface of recycled aggregate;the contents of adhered mortar were between from 35.94%to 38.99%by varying the recycled aggregate size from 10.0 mm to 31.5 mm.In addition,the recycled aggregate with a particle size in the range of from 16.0 mm to 20.0 mm have the lowest content of adhered mortar,and therefore have higher quality and performance compared with other particle sizes.The recycled aggregate percentage in range of this particle size should be increased appropriately during the design of mix proportion,which can reduce the deterioration of the mechanical properties of recycled aggregate concrete by the adhered mortar.