次生孔隙缺陷对混凝土拉压强度影响试验研究

Experimental Study on the Effect of Secondary Pore Defects on the Tensile and Compressive Strength of Concrete

混凝土内部次生孔隙缺陷对其拉压强度影响显著。运用多种尺寸的EPS颗粒模拟混凝土内部的次生孔隙率与孔径分布,对不同次生孔径及孔隙率下的混凝土抗压强度和劈裂抗拉强度进行了研究,并基于灰色关联度理论开展了次生孔隙率和孔径对混凝土抗压强度和劈裂抗拉强度的关联性分析。研究结果表明:混凝土抗压强度和劈裂抗拉强度均随着次生孔隙率的增大呈近似线性下降趋势。混凝土抗压强度随着次生孔径的增大而下降,而劈裂抗拉强度则随着次生孔径的增大呈先降后增趋势,且孔径为4 mm时降幅达到最大值。随着次生孔隙率的增大,混凝土抗压强度和劈裂抗拉强度的降幅均增大。灰色关联度分析结果表明,相较于次生孔隙率,次生孔径对混凝土抗压强度和劈裂抗拉强度的影响更为显著。

The secondary pore defects inside concrete have significant impact on its tensile and compressive strength.The secondary porosity and pore size distribution inside concrete was simulated by various sizes of EPS particles.The compressive strength and splitting tensile strength of concrete were studied under different secondary porosity and pore sizes.Based on the grey correlation theory,the correlation analysis between secondary porosity and pore size on the compressive strength and splitting tensile strength of concrete was conducted.The research results indicate that the compressive strength and splitting tensile strength of concrete exhibit an approximately linear decreasing trend with the increase of secondary porosity.The compressive strength of concrete decreases with the increase of secondary pore size,while the splitting tensile strength shows a trend of first decreasing and then increasing with the increase of secondary pore size,which reaches the maximum value when the pore size is 4 mm.With the secondary porosity increases,both the decrease in compressive strength and splitting tensile strength of concrete also increases.The grey correlation analysis results indicate that the influence of secondary pore size on the compressive strength and splitting tensile strength of concrete is more significant compared with the secondary porosity.