城市废弃混凝土骨料再生混凝土的力学性能研究

Mechanical Properties of Recycled Aggregate Concrete from Urban Waste Concrete

以城市废弃混凝土为研究对象,研究了废弃混凝土块取代天然碎石对再生混凝土抗压强度的影响,通过试验及试验数据分析,得出废弃混凝土骨料不同掺量和养护龄期对再生混凝土的力学性能影响规律。结果表明:再生混凝土的抗压强度随废弃混凝土块取代率的增加呈现先增强后下降的趋势,当废弃混凝土块掺量(质量分数)为35.2%时,再生混凝土抗压强度最大,废弃混凝土块的加入与原天然碎石的抗压强度基本一致,能够保证混凝土的设计强度;当废弃混凝土块的掺量为55.2%时,再生混凝土抗压强度呈直线下降趋势,强度已不能满足设计的要求。研究表明,城市废弃混凝土块掺量为35.2%时,再生混凝土力学性能最好。

In this paper,the effect of waste concrete blocks replacing natural crushed stone on the compressive strength of recycled concrete was studied;the influence of different amounts of waste concrete aggregate and curing age on the mechanical properties of recycled concrete was analyzed on the basis of testing results.The results show that the compressive strength of recycled concrete increases first and then decreases with the increase of the replacement ratio of waste concrete blocks.When the content of waste concrete blocks(mass fraction)is 35.2%,the compressive strength of recycled concrete is the highest,and the compressive strength of waste concrete block is basically consistent with that of natural crushed stone,which can ensure the design strength of concrete.When the content of the waste concrete block is 55.2%,the compressive strength of recycled concrete shows a straight-line decreasing trend,and the strength can not meet the design requirements.It can be concluded that the mechanical properties of recycled concrete are the best when the content of waste concrete blocks is 35.2%.