建筑用再生混凝土制备与抗冻性能研究

Research on Preparation and Frost Resistance of Recycled Concrete for Construction

通过破碎废弃混凝土块制得再生粗细骨料和保温砌块,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。本文利用冻融循环试验研究了再生混凝土保温砌块的耐久性。以质量损失、相对动弹性模量和收缩值作为主要性能指标分析不同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。

Recycled coarse and fine aggregates are prepared by crushing waste concrete blocks and recycled concrete heat preservation blocks.It could not only improve the utilization of recycled concrete,but also solve the problems of waste concrete stacking and environmental pollution.In this paper,the freeze-thaw cycle tests were used to study the durability of recycled concrete insulation blocks.The different factors that affect durability of recycled concrete insulation blocks were analyzed by using the mass loss,relative dynamic elastic modulus and shrinkage value as the main performance indicators.The sensitivity was analyzed by using range analysis method.The results show that after 25 freeze-thaw cycle tests,the mass loss rate meets the requirement for freeze resistance(lower than 5%).The water-binder ratio,the replacement rate of recycled coarse aggregate and the amount of vitrified microbeads are the main factors affecting the durability of recycled concrete.