DIC方法测量高温后轻骨料混凝土弹性模量应用研究

Research on the Application of DIC Method to Measure the Elastic Modulus of Lightweight Aggregate Concrete after High Temperature

应用数字图像相关方法(DIC)测量轻骨料混凝土的弹性模量,同电阻应变片测量方法进行对比分析,研究DIC方法应用于测量混凝土弹性模量中的可行性,应用DIC方法研究不同纤维掺量及高温作用对玄武岩纤维轻骨料混凝土弹性模量的影响.结果表明:应用DIC方法测量轻骨料混凝土应力-应变曲线线性较好,且与电阻应变片测得结果相差不大,可应用于混凝土静力受压弹性模量试验.轻骨料混凝土中掺入玄武岩纤维可提高其弹性模量,且随纤维体积掺量的增加呈先增后减的变化趋势,体积掺量0.2%时弹性模量最大.随着温度的升高,弹性模量总体下降,温度不超过300℃时,玄武岩纤维性能未发生明显衰减,仍可增加轻骨料混凝土的弹性模量.

Applying Digital Image Correlation(DIC)method to measure the elastic modulus of lightweight aggregate concrete,comparative analysis with resistance strain gauge measurement methods,feasibility of applying DIC method to measure the elastic modulus of concrete,application of DIC method to study the influence of different fiber content and high temperature action on the elastic modulus of basalt fiber lightweight aggregate concrete.The results indicate that:The application of DIC method to measure the stress-strain curve of lightweight aggregate concrete shows good linearity,there is not much difference between the results measured with the resistance strain gauge.It can be applied to the static compression elastic modulus test of concrete.Adding basalt fibers to lightweight aggregate concrete can improve its elastic modulus,with the increase of fiber volume fraction,there is a trend of first increasing and then decreasing,the maximum elastic modulus occurs when the volume content is 0.2%.As the temperature increases,the overall elastic modulus decreases,when the temperature does not exceed 300℃,the performance of basalt fibers does not significantly decline,and the elastic modulus of lightweight aggregate concrete can still be increased.