Concrete Carbonation of Deep Burial Storage Constructions under Model Aging Conditions

To ensure the safe operation of concrete structures of deep-burial storages, it is necessary to research the degradation mechanisms of such structures. Concrete carbonation is one of the key factors determining the service life of concrete structures. Existing methods for the concrete carbonation process research at various stages of the building structure life cycle make it possible to conduct model tests in the shortest possible time by simulating the operational factors influencing the corrosion process development. The authors carried out model tests of concrete of deep-burial storages using the method of accelerated concrete carbonation and by taking into account the effects of elevated temperatures. When exposed to elevated temperatures during carbonation, concrete samples exhibit a decrease in compressive strength in the first 56 days of testing by an average of 1.6 MPa. However, by the end of the tests (168 days), the strength of concrete samples at elevated temperatures is on average 4 MPa higher. The microstructure and carbonation dynamics were studied by XRD, TGA and SEM. The data obtained in the research can be used to develop models for predicting the service life of concrete structures of deep-burial storages.