再生混凝土粘结性能试验研究

Experimental study on bonding properties of recycled concrete

摘要:

为进一步在实际工程中推广应用再生混凝土,通过再生混凝土拔出试验,研究再生粗骨料、细骨料取代率,水灰比及锚固条件对再生混凝土抗压强度、粘结性能的影响.结果表明:再生混凝土的粘结强度随再生粗骨料取代率增加而增加,在粗骨料取代率约为60%时取得最大值,随后降低;再生混凝土的粘结强度随再生细骨料取代率增加而降低;再生混凝土的粘结强度优于普通混凝土;过多掺入再生粗、细骨料会降低再生混凝土抗压强度;降低水灰比可提高再生混凝土抗压强度及粘结强度,水灰比变化对再生混凝土抗压强度的影响较普通混凝土小;适当增加保护层厚度(≤3 d)及锚固长度可以提高再生混凝土粘结强度.

Abstract:

To promote the use of recycled concrete in practical engineering,pull-out tests were carried out to study the influence of Coarse/Fine Recycled Concrete Aggregate(CRCA/FRCA) replacement rate,water-cement ratio and the anchoring conditions on the compressive strength and bonding properties of Recycled Aggregate Concrete(RAC).The results show that: the bond strength of RAC rises with the increasing of CRCA replacement rate,and arrives at the maximum when the rate= 60%,then reduces;the bond strength of RAC reduces while the FRCA replacement rate increases,and it is better than that of ordinary concrete;too much CRCA/FRCA replacement will reduce the compressive strength of RAC;lower water-cement ratio can improve the compressive strength and bond strength of RAC,and water-cement ratio variation has less influence on RAC than that of ordinary concrete;appropriate increase in the thickness of concrete cover(≤3 d) and the anchorage length can increase the bond strength of RAC.In addition,by concerning the relationship between the bond strength of RAC and CRCA/FRCA replacement rate,water-cement ratio,compressive strength,anchorage length,a formula was established.