混凝土圆柱体早期收缩徐变性能试验研究

Test Analysis on the Performance of Early Shrinkage and Creep of Concrete Cylinders

通过恒温恒湿条件下对素混凝土徐变柱在不同加载龄期下进行短期持荷试验,得到了混凝土圆柱体早期收缩徐变规律,对比了不同加载龄期下混凝土圆柱体早期徐变性能差异性.试验表明:混凝土早期收缩应变随时间逐步增大,收缩应变率变化较小,早期体外收缩应变较体内收缩应变要大,体内外收缩应变差值随着时间有增大趋势;混凝土早期徐变系数随持荷时间而增大,徐变增长速率逐步减小,混凝土圆柱体体内实测徐变系数较体外实测徐变系数偏小;在持荷初期阶段,加载龄期越大,徐变系数越小,徐变系数增长速率越快.

The short-term shrinkage and creep experiment of concrete cylinders with different loading ages is done under the condition of the constant temperature and humidity, to get the early shrinkage and creep law of concrete cylinders, compared the early creep performance of concrete cylinders under difference loading age. The test shows that the early concrete shrinkage strain increased gradually with time, the slope of time travel curve of shrinkage strains are changed smaller, the early internal shrinkage strains are generally less than external shrinkage strains, the difference between internal shrinkage strains and external shrinkage strain increased over time. The early concrete creep increased gradually with time, the slope of time travel curve of creep is smaller with time, the internal creep coefficient of measured values is generally smaller than external creep coefficient in concrete cylinders. In the early stages of loading, the larger loading age of concrete columns, the smaller of concrete creep coefficient, the faster rate becomes growth of creep coefficient.