长龄期泵送混凝土回弹特性研究

Using 2.207J ordinary rebound hammer and 5.5J high-strength rebound hammer to measure the rebound values of concretes standard test block varied from C20 to C60 at the same time. Using the rebound value and compressive strength fitting under three different linear regression, set up strength curve of two kinds of rebound hammer, explore the suitability of different rebound hammer and different linear for long age pumping concrete. Comparative of long age pumping concrete strength curve with the short period of concrete strength curve. The results showed that: the power function equation of 2.207 J ordinary rebound hammer has the best fitted curve for long age pumping concrete; Long age pumping concrete rebound value is higher than young period of concrete, and the higher the compressive strength of pumped concrete, the rebound value deviation is larger; Long age rebound curve has very good modify relation with the local regulations of measuring curves.