钢管再生混合混凝土徐变性能试验研究

为研究加载龄期对钢管再生混合混凝土徐变性能的影响，开展了12组试件的徐变试验，得到了不同加载龄期下的徐变系数-持荷时间和徐变应变-持荷时间曲线。分析了徐变系数的变化规律和不同算法预测试件徐变应变的有效性。研究结果表明：无论是钢管混凝土试件还是钢管再生混合混凝土试件，加载龄期越早，徐变系数越大，加载龄期对钢管再生混合混凝土试件徐变系数的影响较钢管混凝土试件小；加载龄期相同时，钢管再生混合混凝土试件的徐变系数较钢管混凝土柱的小，加载龄期越晚，两者相差越小。提出了基于Counto模型的龄期调整的有效模量法预测试件的徐变应变，计算结果与试验结果总体吻合良好。

Experimental study on creep behavior of steel tubular columns filled with compound concrete made of demolished concrete lumps and fresh concrete

In order to study the effects of loading age on the creep behavior of steel tubular columns filled with compound concrete made of demolished concrete lumps and fresh concrete, basic creep tests were performed on twelve groups of specimens. The creep coefficient-time curves and creep stain-time curves under different loading ages for each specimen were obtained and analyzed. The effectiveness of variation of creep coefficient and different calculation methods to predict the creep strain of specimens were studied. The results show that: for both concrete-filled steel tube specimens and steel tubular column specimens filled with compound concrete, the creep coefficient increases with the increasing loading age, and the effect of loading age on the latter is less than that on the former. For the same loading age, the creep coefficient of steel tubular columns filled with compound concrete is smaller than that of the concrete-filled steel tube, and the difference between the two decreases with the loading age. The age-adjusted effective modulus method based on the Counto model is presented to predict the creep stain of specimens, and the calculated values are in good agreement with the experimental results.