论文部分内容阅读
基于浮石轻骨料混凝土为基础,将不同质量的风积沙作为细骨料替代部分河砂,研究风积沙轻骨料混凝土冻融损伤机理及服役寿命.通过室内快速冻融循环试验,定量分析风积沙轻骨料混凝土的抗冻耐久性能.在整个冻融循环期内,相对动弹性模量的变化规律可分为直线下降阶段、直线+曲线下降阶段、曲线下降阶段.以此为基础,建立轻骨料混凝土直线和曲线双段式相对动弹性模量衰减方程,依据5组混凝土的抗冻试验结果对方程进行了验证,并预测其在西部地区的服役寿命.结果表明:直线和曲线双段式的相对动弹性模量衰减方程能够准确的反应混凝土冻融损伤劣化规律.风积沙最优替代率为20%,可以满足25 a的使用寿命.损伤模型可为沙漠地区混凝土使用提供一定的理论依据.
Based on pumice lightweight aggregate concrete, aeolian sand of different mass was used as fine aggregate to replace part of river sand to study the freeze-thaw damage mechanism and service life of aeolian sand lightweight aggregate concrete.Through rapid indoor freeze-thaw cycle test, The analysis of the frost resistance and durability of the wind-blown sand lightweight aggregate concrete.Changes of the relative dynamic elastic modulus during the whole freeze-thaw cycle can be divided into the straight-down phase, the straight-line + curve drop phase and the curve drop phase. Based on the results, the equation of the relative dynamic elastic modulus of straight and curved double-section curves of lightweight aggregate concrete was established, and the service life of the concrete in the west of China was verified according to the results of the frost resistance test of the five groups of concrete.The results showed that the straight line And curve two-stage relative dynamic elastic modulus attenuation equation can accurately reflect the law of freeze-thaw damage deterioration of aeolian sand.The optimum replacement rate of aeolian sand is 20%, which can meet the service life of 25 a.The damage model can be used for the concrete Use to provide some theoretical basis.