基于粗骨料多孔界面的再生混凝土内部相对湿度响应机理试验研究

再生混凝土内部湿度场的变化会对结构的耐久性造成影响。文章基于再生粗骨料界面的多孔特性，对比研究100%取代率下再生混凝土和普通混凝土在不同温度、距离表层不同深度及有、无荷载作用下的内部相对湿度的响应规律及响应机理。结果表明：再生混凝土内部的相对湿度响应速率快于普通混凝土，距离再生混凝土表层越近，相对湿度响应速率越快，且随着温度的增加而增加；弯曲荷载作用对再生混凝土和普通混凝土的相对湿度响应速率均具有促进作用，且对再生混凝土的影响更为显著；对于再生混凝土内部相对湿度滞后上升现象，提出“再生粗骨料分区 界面热湿传递模型”，分析相对湿度滞后上升的机理；采用多元非线性曲线分段拟合的方法，建立再生混凝土内外环境相对湿度响应计算模型。

Experimental study on internal relative humidity response mechanism of#br# recycled concrete based on coarse aggregate porous interface

The durability of the recycled concrete structure can be affected by of its interior humidity fieldIn this work, based on the porous characteristics of the recycled coarse aggregate interface, the response laws and response mechanisms of interior relative humidity of recycled concrete (with 100% replacement ratio) and ordinary concrete are compared under different temperatures, different depths and different loadsThe results show that the interior relative humidity response rate of recycled concrete is faster than that of ordinary concreteThe closer to the surface of recycled concrete it is, the faster the relative humidity response rate (which increases with the temperature) shall beBending load may accelerate the relative humidity response rates of both recycled and ordinary concretes, but its effect on recycled concrete appears to be more significantFor the delayed rise phenomenon of relative humidity in the recycled concrete interior, the “partition interface heat and moisture transfer model of recycled coarse aggregate” is proposed, and the delayed rise mechanism of relative humidity is analyzedThe calculation model for relative humidity response of inner and outer environments of recycled concrete is established by the method of multivariant nonlinear curve segmentation fitting