Long-term behavior of prestressed concrete industrial buildings in chloride-based industrial environments

Abstract

Combined with the main corrosive mediums existing in chloride-based industrial environments, the corrosion mechanisms of concrete and prestressing tendons are expounded, and the strength degradation law of concrete characterized by “acidification depth” with pH value and the equivalent constitutive model of prestressing wires considering stress corrosion are proposed. Taking the prestressed concrete industrial bent frame in the hydrochloric acid mist corrosion environment as a research object, the failure modes of the structural system are determined based on the elastic analysis method, and the stochastic finite element simulation is used to analyze the load effect and resistance stochastic process of the whole structure and key components. The deterioration process of load resistance and serviceability of the structure in the actual industrial environment are explored. Based on the reliability theory, the long-term behaviors of the structure under the combined action of environmental corrosion and load are studied, and the time-variant failure probabilities of the main components are calculated. The results indicate that the expected service life obtained by taking the ultimate limit state of bearing capacity as the failure criterion is more accurate for actual industrial buildings, and the concentration of environmental aggressive agents exerts a significant influence on the durability and safety of key components. When the concentration of hydrochloric acid mist is 30 mg/m³, the expected life of the RC bent columns aligns well with the design service life of 50 years, while the expected life of PC crane beams is only approximately 21 years, which is much lower than the design service life, PC crane beams are more sensitive to the various of concentration of the aggressive agents than reinforced concrete columns.