不同服役寿命的再生混凝土变形性能试验研究

Experimental study on the deformability of recycled concrete w ith different service life

通过收集3种不同来源的废旧混凝土制备出了RA-Ⅰ、RA-Ⅱ、RA-Ⅲ 3种再生粗骨料,进行了粗骨料取代率分别为0、30%、50%、70%、100%的再生混凝土试块变形性能试验,得到了不同服役寿命和不同取代率下RAC的弹性模量和峰值应变。试验结果表明,对于RAC弹性模量,不同再生粗骨料取代率(30%、50%、70%、100%)下RAC弹性模量与NC弹性模量之比均小于1,建立了RAC的立方体抗压强度与弹性模量的计算式,结果与我国现行《规范》较为吻合,说明《规范》对弹性模量的计算方法同样适用于RAC;对于RAC峰值应变,建立峰值应变与轴心抗压强度的计算式,对比分析计算结果,拟合值介于过镇海建立计算式的计算值和英国规范(BSI)之间。

Three kinds of recycled coarse aggregate RA-I,RA-II and RA-III were prepared by collecting three different sources of waste concrete,the block deformation performance of recycled concrete coarse aggregate replacement rate were 0,30%,50%,70%,100%,the different service life and RAC under different replacement ratio of elastic modulus and the peak strain.The test results show that the elastic modulus of RAC,the ratio of RAC′s modulus of elasticity to NC modulus of elasticity under the substitution rate of different recycled coarse aggregate (30%,50%,70% and 100%) is less than 1 one,a calculation formula of RAC compressive strength and elastic modulus,the current “China standard” is consistent with that “the calculation method of the elastic modulus of the standard” also applies to RAC;for the RAC formula of peak strain,peak strain and axial compressive strength,compared with the results of calculation,the fitting value of this paper is between the calculated values of the over Zhenhai establishment formula and the British Standard (BSI).