不同含水率混凝土的分级加载蠕变试验研究

Study on the Creep Characteristics of Concrete with Different Moisture Contents under Step Loading

通过对混凝土试块进行单轴压缩蠕变试验,分析在不同含水率条件下混凝土试块的蠕变性能的变化规律。通过对蠕变曲线进行分析得到,混凝土的蠕变发展速率随着含水率的增加而逐渐增加;对不同含水率混凝土蠕变的变形值进行分析,发现混凝土的含水率对蠕变的变形量有着有利的影响,其中含水率最高的试件的蠕变量是含水率最低的蠕变量的12倍;通过比较蠕变劲度曲线,发现随着试件含水率的增加,混凝土的蠕变劲度呈逐渐减小的趋势,其中最大降低了44.49%,这表明含水率对混凝土的蠕变有着促进作用;对比试验结果与利用Burgers模型进行数值拟合所得出的模型的各个参数,可以得到不同含水率试件的蠕变特性,试件含水率越高,黏塑性模量越高,蠕变变形越大。

The uniaxial compression creep tests of concrete specimens were carried out to analyze the change rules of creep prop- erties of concrete specimens under different water contents. The analysis on the creep curve of concrete indicated that the creep development rate of concrete gradually increased with the increase of water content. Meanwhile, through analyzing the creep deformation value of concrete with different water contents, it was found that the water content of concrete had a beneficial effect on the creep deformation. The creep value of the concrete specimens with the highest water content was 12 times of that of the concrete specimens with the lowest water content. By comparing the creep stiffness curve, it was found that with the in- crease of the water content of specimens, the creep stiffness of concrete gradually decreased within 44.49~//00, which proved that the water content had an obvious catalytic effect on the creep of concrete. The test results were compared with the parameters of models obtained by numerical fitting from Burgers model, which accurately reflected the creep characteristics of concrete specimens under different water contents. The higher the water content of specimens, the larger the viscoplasticity modulus and the creep deformation.