EFFECT OF STATIC AND FATIGUE LOADING ON CARBONATION RESISTANCE OF UNDERGROUND STRUCTURE CONCRETE

摘要

Underground structure usually suffers much more complex service environment than any other concrete structures.Due to the internal forces of the structure and vibration of urban rail transit, underground structure concrete is under static and fatigue loading during entire service life.Furthermore, the temperature and humidity in underground structure is exactly beneficial to carbonation reaction which is one of common deterioration mechanisms leading to degradation of concrete.And the degradation will usually speed up under combined action of carbonation and loading.In this paper, effect of static and fatigue loading on carbonation resistance of underground structure concrete is discussed.Accelerated carbonation tests coupling with static loading and fatigue loading are described respectively.Then carbonation depth and pH value of concrete are summarized at different carbonation age and under different loading condition.Finally, possible reasons for change regularity of carbonation depth and pH value are analysed.