图像分析宏观孔孔隙率对混凝土抗压强度的影响

发布时间：2018-02-26 07:11

本文关键词： 混凝土含气量宏观孔孔隙率抗压强度图像法　出处：《建筑材料学报》2015年02期 　论文类型：期刊论文

【摘要】：采用不同种类的气孔调节材料配制出15种不同含气量(体积分数)的混凝土.研究了混凝土3,7,28d抗压强度与含气量之间的关系;采用图像法研究了不同含气量混凝土中孔径大于200×103 nm的宏观孔孔隙率(体积分数);对比分析了混凝土宏观孔孔隙率和含气量对混凝土28d抗压强度的影响规律.结果表明:混凝土28d抗压强度与含气量的线性关系较强,而混凝土3d和7d抗压强度与含气量的线性关系较弱;混凝土28d抗压强度对宏观孔孔隙率变化的敏感性显著高于其对含气量变化的敏感性,即混凝土中宏观孔孔隙率变化对其28d抗压强度影响更大;调整气孔调节材料的品种,可使混凝土含气量从1.5%提高到9.0%,而宏观孔孔隙率只从0.81%增加到1.48%,其所占含气量的比例从超过55%降低到16%左右,即可在有效调节混凝土含气量的同时,控制其宏观孔的数量.
[Abstract]:Fifteen kinds of concrete with different air content (volume fraction) were prepared by using different kinds of pore regulating materials. The relationship between compressive strength and gas content of concrete was studied. The macroscopic pore porosity (volume fraction) with pore diameter larger than 200 脳 103 nm in concrete with different air content was studied by image method, and the effect of macro pore porosity and air content on compressive strength of concrete for 28 days was compared and analyzed. The results show that the linear relationship between 28d compressive strength and gas content of concrete is strong. However, the linear relationship between 3D and 7d compressive strength of concrete and gas content is weak, and the sensitivity of 28d compressive strength to the change of macro pore porosity is significantly higher than that of concrete with respect to the change of gas content. That is, the change of macroscopic pore porosity in concrete has more influence on its 28d compressive strength. The air content of concrete can be increased from 1.5% to 9.0, while the macroscopic porosity of concrete can only be increased from 0.81% to 1.48, and the proportion of gas content in concrete will be reduced from 55% to 16%, which can effectively regulate the air content of concrete and control the number of macroscopic pores.
【作者单位】：同济大学先进土木工程材料教育部重点实验室;
【基金】：国家自然科学基金资助项目(51302189)
【分类号】：TU528

【参考文献】