混凝土的碳化作用能提高其表面硬度，现行无损检测规程把碳化深度作为回弹法测强的一个修正参量来采用。研究发现在某种场合用酚酞试剂测定到的碳化值，不一定是实质意义上氢氧化钙和二氧化碳反应生成的碳酸钙，该疑似混凝土碳化深度值实际是混凝土表层失碱产生的中性化现象，研究揭示了回弹法检测中酚酞试剂指示的假性碳化引起混凝土检测强度评判的误区。

The rigidity of concrete surface can be developed by its carbonation. In the valid guild regulations, the depth of carbonation is used as a modificatory parameter in rebound method of strength measurement. The investigation showed that carbonize value measured by phenolphthalein reagent is not always the calcium carbonate inborned by the reaction of calcium hydroxide and carbon dioxide essentially. It seems like that the depth of carbonation is the phenomenon of neutralness resulted by losing alkali in the concrete surface layer actually. It indicates that the miscarriage of justice pseudo-carbonation showed by phenolphthalein reagent in rebound method is the mistake of concrete strength test.