硫酸盐环境多因素耦合作用活性粉末混凝土损伤劣化研究

The durability of reactive powder concrete exposed to sulfate attack circumstance based on multi-factor effects will be researched in this project. The main context of this study includes three parts: the microstructure characteristics of reactive powder concrete after sulfate attack, the damage evolution and performance deterioration of reactive powder concrete under sulfate attack circumstance and the effect of multi-factor circumstance. The transformation and crystallization regular of corrosive ions in the porosity of reactive powder concrete under sulfate attack circumstance will be given and modified diffusive-reactive theoretical model by thermodynamics will be established through SEM analytical techniques and TG-DSC testing. The performance degradation and deterioration mechanism of reactive powder concrete will be revealed and damage evolution model under multiple factors with environment, mechanics and concrete self-element will be set up by durability damage additive effect of reactive powder concrete exposed to sulfate attack circumstance considering flexural loads, freeze - thaw cycles. The damage criterion under sulfate attack circumstance will be raised and life prediction model will be established based on discussion on performance degradation of reactive powder concrete under sulfate attack circumstance based on multi-factor effects. Though the research about this project not only to supply basic data for durability design and estimate of reactive powder concrete under sulfate attack circumstance based on multi-factor effects but also to prepared theoretical basis for solve major scientific problems of durability damage of reactive powder concrete project. So this research have important academic significance.

本项目拟开展硫酸盐环境多因素耦合作用下活性粉末混凝土耐久性研究，主要包括硫酸盐侵蚀、硫酸盐和冻融循环耦合作用、硫酸盐和弯曲荷载耦合作用下活性粉末混凝土损伤演变与性能劣化规律。通过SEM分析技术与TG-DSC测试技术，阐明硫酸盐环境下侵蚀性离子在活性粉末混凝土孔隙中的迁移及晶化规律，建立热力学修正后活性粉末混凝土扩散-反应理论模型；综合考虑弯曲荷载、冻融循环对硫酸盐环境下活性粉末混凝土耐久性损伤的叠加效应，揭示活性粉末混凝土性能退化规律与劣化机理，建立综合考虑环境因素、力学和混凝土自身因素的损伤演化模型；基于硫酸盐环境多因素耦合作用下活性粉末混凝土性能劣化规律的分析，提出硫酸盐侵蚀环境下损伤破坏准则并建立寿命预测模型。通过本项目研究，为硫酸盐环境多因素耦合作用下活性粉末混凝土耐久性设计与评估提供科学依据，为解决活性粉末混凝土工程耐久性损伤的重大科学问题奠定理论基础，具有重要的理论意义。

本项目开展了硫酸盐环境下活性粉末混凝土耐久性研究，主要包括硫酸盐侵蚀、硫酸盐侵蚀和弯曲荷载耦合作用、硫酸盐侵蚀和冻融循环耦合作用下活性粉末混凝土的损伤演变与性能劣化规律。通过宏观试验与微观分析相结合的方法，考虑弯曲荷载、冻融循环对硫酸盐环境下活性粉末混凝土结构耐久性损伤的叠加效应，揭示了其性能退化规律与劣化机理，建立了多因素下活性粉末混凝土疲劳损伤模型，并进行硫酸盐侵蚀环境下的寿命预测。通过本项目研究，为硫酸盐侵蚀环境下活性粉末混凝土耐久性设计与评估提供科学依据，为解决活性粉末混凝土工程耐久性损伤的重大科学问题奠定理论基础，具有重要的理论意义。