回弹法到底怎么用

Application of rebound method

回弹法是检测混凝土表面一些点的硬度。但这些点的硬度因混凝土各组分排列的差异而各不相同,因此回弹值就有很大的偶然性,用它推算出的混凝土整体强度也就具有很大的偶然性。所谓碳化就是水泥水化生成的Ca(OH)2在空气中缓慢变成了CaCO3,前者是碱性,能使酚酞试剂变红;后者是中性,酚酞试剂不变红。但粉煤灰等掺合料不生成C(a OH)2。因此,用变不变红来反映混凝土是否碳化就谬误了。回弹法正在被滥用,应让"脱缰野马"回归原位。

The rebound method is used to test the hardness of some points on the surface of concrete.Bnt the hardness on these points are various from different concrete composites.And the rebound value features for occationality, as well as the integral strength.Carbonation means Ca（OH）： hydrated from the cement changes to CaCO3 in the air.The Ca（OH）2 is alkalic and can change phenlphthalein to be red;the CaCO3 is neutral and can not change the phenlphthalein to be red.But the fly ash will not transformed to Ca（ OH）2.So the recognition method by the color changing is wrong. The rebound method is misused, we shall adjust the method.