湿度对建筑混凝土材料耐久性影响仿真分析

Simulation Analysis of Influence of Humidity on Durability of Building Concrete Materials

建筑混凝土的养护条件、材料组成以及工作环境等因素对其使用寿命的影响较为显著。针对现代混凝土抗碳化性能差,耐久寿命短的问题,提出湿度对建筑混凝土材料耐久性影响分析方法。构建非耦合湿热传输模型、耦合湿热传输模型以及混凝土构件的力学平衡方程。结合混凝土材料的松弛和蠕变两种力学行为,获取潮湿环境下混凝土耗能。构建湿度场数学模型,研究潮湿环境中建筑混凝土材料的耐久性受湿度的影响。仿真测试结果表明,建筑混凝土的变形受湿胀作用的影响较大。随着水分在混凝土梁上的扩散,混凝土的压应变和拉应变不断增大。只考虑弹性模量变化时,混凝土的应变受环境湿度的影响较小。

Traditionally,factors such as curing condition,material composition and working environment of building concrete have significant influence on the service life.Due to low carbonation resistance and short durability life of modern concrete,this paper puts forward a method of analyzing the influence of humidity on durability of building concrete.The uncoupled heat-moisture transfer model,coupled heat-moisture transfer model and the mechanical balance equation of concrete members were constructed.Based on the relaxation and creep mechanical behaviors of concrete materials,the energy dissipation of concrete in wet environment was obtained by combining.Moreover,a mathematical model of humidity field was built to research the influence of humidity on durability of building concrete materials in humid environment.Simulation results show that the deformation of building concrete is greatly affected by hygro-expansion;The compressive and tensile strains of concrete increase with the diffusion of water on the concrete beam.It can be concluded that,when only elastic modulus is considered,the strain of concrete is less affected by ambient humidity.