自密实再生混合混凝土的单轴受压试验研究

发布时间：2017-12-30 23:19

本文关键词：自密实再生混合混凝土的单轴受压试验研究　出处：《建筑结构学报》2016年S2期 　论文类型：期刊论文

【摘要】：将高强度等级的自密实新混凝土和低强度等级的废旧混凝土块体混合浇筑,制作了8个300 mm×300 mm×300 mm立方体试件和8个300 mm×300 mm×600 mm棱柱体试件,对其进行了单轴受压试验,研究了废旧混凝土块体取代率(0、20%、30%和40%)和试件形状(立方体和棱柱体)对自密实再生混合混凝土受压性能的影响。研究表明:自密实再生混合混凝土中废旧混凝土块体与新混凝土的界面并非是明显的薄弱部位;随着废旧混凝土块体取代率的增大,自密实再生混合混凝土的组合抗压强度和弹性模量都逐渐降低,废旧混凝土块体取代率对组合抗压强度的影响相比弹性模量更为显著;当荷载比小于0.8时,自密实再生混合混凝土泊松比随荷载比的增长速度与新混凝土相差不大;当荷载比位于0.8~0.9区间时,前者泊松比随荷载比的增长速度明显快于后者。并在试验结果的基础上,提出了自密实再生混合混凝土组合抗压强度、弹性模量和峰值应变的计算方法。
[Abstract]:The new self-compacting concrete with high strength grade and the waste concrete block with low strength grade are mixed. Eight cubic specimens of 300mm 脳 300mm 脳 300mm and eight prisms of 300mm 脳 300mm 脳 600mm were made. The uniaxial compression test was carried out, and the replacement ratio of waste concrete blocks was studied by 20%. 30% and 40 bars and specimen shapes (cubes and prisms). The study shows that the interface between the old concrete block and the new concrete is not obviously weak in the self-compacting recycled mixed concrete. With the increase of the replacement ratio of waste concrete blocks, the combined compressive strength and elastic modulus of self-compacting recycled mixed concrete are gradually decreased. The influence of the replacement ratio of waste concrete blocks on the compressive strength of the composite is more significant than that of the elastic modulus. When the load ratio is less than 0.8, the growth rate of Poisson's ratio with load ratio is similar to that of new concrete. When the load ratio is in the range of 0.8 ~ 0.9, the Poisson's ratio of the former is obviously faster than that of the latter. On the basis of the experimental results, the compressive strength of the self-compacting recycled mixed concrete composite is proposed. The calculation method of elastic modulus and peak strain.
【作者单位】：华南理工大学亚热带建筑科学国家重点实验室;中国建筑科学研究院;
【基金】：国家自然科学基金重点项目(51438007) 广州市科学(技术)研究专项重点项目(201607020005) 亚热带建筑科学国家重点实验室自主课题(2013ZB24,2015ZB21)
【分类号】：TU528
【正文快照】： 0引言随着我国城市化进程的加快,新建工程将消耗大量砂、石和水泥;与此同时,既有建(构)筑物的拆除又产生大量废旧混凝土,其堆放填埋也对环境造成负面影响。若将废旧混凝土科学地应用于新建工程,不仅可减少固体废弃物排放,还能明显降低新混凝土的消耗。针对传统再生骨料混凝土

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