小芯样弧面对压法检测预拌泵送混凝土抗压强度研究

Study on Compressive Strength of Ready Mixed Pumping Concrete by Arc Pressure Method with Small Core Sample

试验研究小芯样径向对压应力与混凝土抗压强度的关系。在预拌泵送混凝土浇筑成型的大型足尺结构模型剪力墙混凝土中钻取直径38mm小芯样,由专用试验装置测试其径向混凝土对压力,并对应测区钻取标准直径芯样得到芯样试件抗压强度,采用单因素试验分析金刚砂耦合材料目数/硬度和试件混凝土干湿程度对小芯样对压强度的影响,确定小芯样对压试件样本最小取样数量,采用最小二乘法原理回归得到小芯样弧面对压法检测混凝土测强曲线。试验结果表明,混凝土干湿程度、受压截面位置与金刚砂目数及硬度对小芯样试件对压强度影响不显著;小芯样对压试件的取样数量不宜少于5个;建立的小芯样弧面对压法检测预拌泵送混凝土专用测强曲线可用于工程结构实体混凝土强度检测,研究结果可供结构混凝土强度质量检测与控制参考。

The relationship between radial compressive stress of small core sample and compressive strength of concrete is studied. Small core samples with diameter of 38mm were drilled in the shear wall concrete of large-scale structure model cast by ready mixed pumping concrete. The radial concrete pressure was tested by a special test device, and the compressive strength of core samples was obtained by drilling standard diameter core samples corresponding to the test area. The effects of mesh/hardness of emery coupling material and the degree of concrete drying and wetting on the compressive strength of small core samples were analyzed by single factor test According to the influence of compressive strength, the minimum sampling quantity of small core sample on compressive specimen is determined, and the strength curve of small core sample is obtained by least square regression. The test results show that the dry and wet degree of concrete, compressive section position and the mesh number and hardness of emery have no significant influence on the compressive strength of small core samples;it is suggested that the number of small core samples should not be less than 5;the special strength curve of small core samples for testing ready mixed pumping concrete by arc pressure method can be used for the strength testing of engineering structural solid concrete. The research results can be used as a reference for the quality inspection and control of structural concrete strength.