母体混凝土强度对再生骨料及再生骨料混凝土性能影响研究进展

Research Progress on Influence of Parent Concrete Strength on Properties of Recycled Aggregate and Recycled Aggregate Concrete

将建筑固废破碎成再生骨料加以使用,既可节约自然砂石资源,又可促进建筑固废循环利用。再生骨料的品质决定了再生混凝土的性能,而品质的影响因素很多,其中母体混凝土的强度是重要的影响因素之一。本文以母体混凝土强度为研究对象,综述其对再生骨料及再生骨料混凝土的性能影响规律。不同强度的母体混凝土通过影响再生骨料黏附砂浆的质量与含量,进而影响再生骨料及再生骨料混凝土的性能。母体混凝土强度增加,黏附砂浆的质量与含量均得到提高;而黏附砂浆质量的提高强化了再生骨料和再生骨料混凝土的性能;黏附砂浆含量的增加劣化了再生骨料的物理性能,使再生骨料孔隙率和吸水率增加,却强化了混凝土的内养护效果,有助于提升再生骨料混凝土的力学性能。微观分析发现,对于不同强度的母体混凝土,再生骨料混凝土界面过渡区中水化产物的含量有差异,从而对混凝土的力学性能产生影响。本文为再生骨料的进一步分级利用提供参考。

The use of recycled aggregate obtained from the crushing of construction solid waste can not only save natural sand and gravel resources,but also promote the recycling of construction solid waste.The quality of recycled aggregate determines the performance of recycled aggregate concrete.There are many factors affecting the quality of recycled aggregate,and the strength of parent concrete is one of the important influencing factors.The article takes strength of parent concrete as the research object,and summarizes its influence law on the properties of recycled aggregate and recycled aggregate concrete.Different strengths of parent concrete affect the quality and content of recycled aggregate adhesive mortar,which in turn affects the properties of recycled aggregate and recycled aggregate concrete.When the strength of parent concrete increases,the quality and content of adhesive mortar are improved.While the quality of adhesive mortar is improved,the properties of recycled aggregate and recycled aggregate concrete are strengthened.The increase in the content of adhesive mortar deteriorates the physical properties of recycled aggregate,increases the porosity and water absorption of recycled aggregate,but strengthens the internal curing effect of concrete,which contributes to the mechanical properties of recycled aggregate concrete.Using microscopic analysis,it is found that different strength of parent concrete make a difference in the content of hydration products in the interfacial transition zone of recycled aggregate concrete,which has an impact on the mechanical properties of concrete.The article provides a theoretical basis for further grading and utilization of recycled aggregate.