绿色建筑材料再生混凝土渗透力学行为系统性试验研究

Systematic Experimental Study on the Permeability Mechanical Behavior of Green Building Material Recycled Concrete

为研究绿色建筑材料再生混凝土的渗透、力学行为特征,通过室内渗透测试、静、动三轴力学试验方法,开展了不同再生粗骨料粒径下试样渗透、力学特征分析。研究表明,再生粗骨料粒径愈大,则试样渗透率愈低,但粗骨料粒径变化,不会影响渗透率与静水围压之间函数关系,且加载破坏后,粗骨料粒径对渗透特性影响不及加载前。静力荷载下,围压对应变发展影响具有主导地位,粗骨料粒径愈大,试样三轴峰值应力愈高。动力荷载下,动弹性模量随应变呈“递减-稳定”变化,围压5 MPa、25 MPa下动弹性模量稳定期节点应变分别为3.03%、4.6%;粗骨料粒径、围压作用与动弹性模量均为正相关特征。粗骨料粒径对混凝土弹性应变能影响不及围压作用,且不会改变混凝土弹性应变能的发展趋势。研究成果对认知再生混凝土的渗透、力学特征以及试验设计具有参考价值。

In order to study the permeability and mechanical behavior characteristics of green building material recycled concrete,indoor permeability testing,static and dynamic triaxial mechanical testing methods were used to analyze the permeability and mechanical characteristics of samples under different recycled coarse aggregate particle sizes.Research has shown that the larger the particle size of recycled coarse aggregate,the lower the permeability of the sample.However,changes in the particle size of coarse aggregate do not affect the functional relationship between permeability and static water confining pressure.Moreover,after loading failure,the influence of coarse aggregate particle size on permeability characteristics is less significant than before loading.Under static load,the influence of confining pressure on strain development plays a dominant role,and the larger the coarse aggregate particle size,the higher the triaxial peak stress of the specimen.Under dynamic loads,the dynamic elastic modulus shows a decreasing stable change with strain.Under confining pressures of 5MPa and 25MPa,the node strains during the stable period of dynamic elastic modulus are 3.03%and 4.6%,respectively;The coarse aggregate particle size,confining pressure,and dynamic elastic modulus are all positively correlated characteristics.The influence of coarse aggregate particle size on the elastic strain energy of concrete is not as significant as that of confining pressure,and it does not change the development trend of concrete elastic strain energy.The research paper has reference value for understanding the permeability,mechanical characteristics,and experimental design of recycled concrete.