更新时间:05-12 上传会员:julu1004
分类:土木工程 论文字数:18898 需要金币:1000个
摘 要:通过破碎废弃混凝土块制得再生粗细骨料,添加玻化微珠这种保温材料制备再生混凝土保温砌块,既可提高再生混凝土利用度,又能解决废弃混凝土的堆置与环境污染问题,是混凝土可持续发展的重要举措。试验研究了再生混凝土保温砌块的耐久性。设计了不同配合比的试块,对试块进行冻融循环试验,以质量损失和相对动弹性模量作为主要性能指标,并用非接触法测定再生混凝土早龄期收缩,以收缩值为指标,分析再生粗骨料取代率、再生细骨料取代率、水胶比,玻化微珠掺量等因素对再生混凝土保温砌块耐久性的影响,运用极差分析法进行敏感性分析。结果表明:经25次冻融循环试验后,质量损失率满足抗冻性能5%的要求;水胶比、再生粗骨料取代率和玻化微珠掺量是影响再生混凝土耐久性的主要原因。添加玻化微珠制作再生混凝土保温砌块是可行的,为再生混凝土的可持续发展指明新的途径。
关键词:再生混凝土;保温砌块;耐久性;抗冻性能;收缩变形;玻化微珠
Abstract: Recycled coarse and fine aggregate were made of the broken waste concrete block and glazed hollow bead were used as the insulation material in the recycled concrete insulation block which can improve the Utilization rate of the waste concrete and reduce the stacking of the abandoned concrete to improve environment pollution. Experiment on the durability of the recycled concrete insulation block. Test block were designed with different mix proportion and freeze-thaw cycle test were carried out of quick freezing method which used the mass loss and relative dynamic modulus of elasticity as the main performance index. Non contact method were used to determine the contraction of the recycled concrete at early age which used shrinkage value as index. Analysis durability of recycled concrete insulation block under different recycled aggregate substitution, different water cement ratio,admixture of glazed hollow bead .The results showed that mass loss rate met 5% after 25cycles of freezing and thawing test; Water cement ratio, replacement ratio of recycled coarse aggregate and the admixture of glazed hollow bead are the main influence factors of the durability of recycled aggregate concrete .Adding glazed hollow bead in recycled concrete thermal insulation block is feasible, which point a new way for sustainable developments of the recycled concrete .
Key words: Recycled Concrete; Thermal Insulation Block; Durability; Frost Resistance; Shrinkage deformation; Glazed hollow bead