装配式结构灌浆料现场实体强度检测技术研究

Research on In-situ Methods of Compressive Strength Testing for Grouting Joints in Precast Structure

文章针对装配式混凝土结构建筑连接节点灌浆料强度现场检测技术,通过试验研究灌浆料表面硬度与灌浆料实际用水量、养护时间和测试位置的关系,并通过回归分析拟合灌浆料表面硬度和抗压强度之间的换算方法,得到表面硬度法测试灌浆料实际抗压强度的换算公式。使用三次函数、幂函数、线性函数和指数函数均可以建立较为准确的灌浆料表面硬度和抗压强度的换算模型。其中,幂函数的拟合效果最好,相对误差和相对标准差满足现有标准体系中专用测强曲线的建立要求且优于现有标准中的推荐值。通过实际工程应用,比对表面硬度法和取样法在装配式建筑工程现场的检测结果,验证其可行性。通过现场取样检测,对灌浆料的抗压强度测试结果进行比对,发现取样法的测试结果略高于表面硬度法的测试结果。

This study was carried out to investigate in-situ non-destructive testing method for compressive strength of grouting joints in precast concrete structures.Regression analysis were taken based on experimental results of surface hardness,curing time,w/c ratio and testing positions grouting specimens.Relations between surface hardness and compressive strength of grouting materials were build in accordance with cubic function,power function,linear function and exponential function.Regression based on power function had best performance among the results,with betterδand er than current technical specimens.The strength curve from power function regression in this study was evaluated in a case study,which results showed the compressive strength calculated from surface hardness of joint materials was slightly lower than results from sampling method.