干燥环境下粉煤灰混凝土表面假性碳化研究OA

It is necessary to measure the carbonation depth of concrete surface by rebound method,and the measurement of carbonation depth of concrete surface will be affected in dry environment.In this paper,the rebound test is carried out by setting up oven-drying group,drying group,standard maintenance group,as well as pier A and pier B.It was found that the carbonation boundary of concrete in dry environment appeared obviously when phenolphthalein was sprayed on it,and the carbonation zone turned pink and red with time.The carbonation of fly ash concrete under dry environment is affected by three aspects:first,the proportion of cement clinker decreases,resulting in the decrease of Ca(OH)2;second,the secondary hydration of fly ash consumes Ca(OH)2;third,the dry environment will further affect the hydration reaction and carbonation of cement,resulting in the crystallization of Ca(OH)2.