再生粗骨料对再生混凝土力学性能及碳化性能的影响

Effect of recycled coarse aggregate on mechanical properties and carbonation behavior of recycled aggregate concrete

与天然骨料相比,再生粗骨料来源复杂且基本性能不稳定,对再生混凝土性能影响较大,因此再生混凝土的应用是工程界十分关注的问题。在普通混凝土的基础上,研究了再生粗骨料的取代率及品质差异对再生混凝土力学性能及碳化性能的影响,研究结果表明:随着RCA取代率的增加,RAC的力学性能及抗碳化性能逐渐降低,且劣于天然骨料混凝土性能,高品质RCA混凝土性能明显优于普通品质RCA混凝土,以掺量100%为例,高品质RCA混凝土比普通品质RCA混凝土抗压强度提高了24.1%,用水量降低了5.6%,碳化深度提高了29.3%;与天然骨料混凝土相比,抗压强度分别降低了5.4%、23.8%,用水量提高了6.1%、12.4%,碳化深度分别提高了29.3%、72.5%。

Compared with the natural aggregate, the recycled coarse aggregate has a complicated source and the basic performance is unstable,which has great influence on the performance of the recycled aggregate concrete.Therefore, the application of recycled concrete is a very important problem in the engineering field.On the basis of ordinary concrete, the influence of the replacement rate and quality differ- ence of recycled coarse aggregate on the mechanical properties and carbonation performance of recycled concrete was studied.The results showed that with the increase of RCA replacement rate, the mechanical properties and carbonization resistance of RAC are gradually re- duced and inferior to the performance of natural aggregate concrete.The high quality of RCA concrete is obviously better than that of ordi- nary quality RCA concrete.Taking the content of 100% as an example ,the compressive strength of high quality RCA concrete is 24.1% higher than that of ordinary quality RCA concrete.The water consumption decreased by 5.6% and the carbonization depth increased by 29.3%.Compared with the natural aggregate concrete, the compressive strength decreased by 5.4% and 23.8%, the water consumption in- creased by 6.1% and 12.4%,respectively, the carbonization depth increased by 29.3% and 72.5%, respectively.