The Effect of the Material Factors on the Concrete Resistance Against Carbonation

The carbonation is one of the main factors to cause the degradation of the properties in the reinforcement concrete structures. In this study, the effect of the material factors, i.e. the type and the particle size of cement, the calcium oxide content in the fly ash, the fineness modulus of fine aggregate, the types and the dosages of superplasticizers (SPs), on the carbonation properties of the concrete was studied. The carbonation coefficient (K) values of the concrete mixtures with various material factors were obtained. The control indexes of the material to resist against carbonation of the reinforced concrete were proposed. The test results show that the type and the particle size of cement, the calcium oxide content in the fly ash and the types of SPs have the significant influence on the carbonation coefficient (K). The concrete mixture with the excellent resistance against carbonation can be prepared by using cement with the fine particle size and the high-calcium fly ash and the PCA SP of lower dosage in the concrete.