再生骨料多元化强化对植生混凝土性能的影响研究

Study on the effect of multiple strengthening methods of recycled aggregate on the properties of planting concrete

为了提高再生骨料植生混凝土性能,研究了再生骨料代替天然骨料不同取代率、碳酸化、骨料级配3种强化方式对其强度和孔隙率的影响,量化了符合植生要求的最佳取代率和最佳骨料级配范围。首先,根据试验结果拟合曲线发现,混凝土抗压强度随着取代率的增加呈现先增加后减小的趋势。当取代率为30%,抗压强度最大,为12.48 MPa;然后,进行碳酸化处理再生骨料和成型试块,发现CO_(2)浓度为99%时,对再生骨料碳酸化7 d,抗压强度可达11.4 MPa,较不处理的试块强度提高了32.56%;接着,采用修正后的Furnas模型研究骨料级配,发现再生小骨料占比为10%~20%时,试块强度和孔隙率可以达到最好的平衡;最后,进行了再生骨料植生混凝土工程应用试验,并取得了良好效果,研究结果可为再生骨料植生混凝土推广应用提供理论依据。

In order to improve the performance of recycled aggregate planting concrete,it studied the influence of three strengthening methods of recycled aggregate replacing natural aggregate with different replacement rate,carbonation and graded aggregate on its strength and porosity,quantified the best replacement rate and the best a graded aggregate range that met the requirements of planting.Firstly,according to the fitting curve of test results,it is found that the compressive strength of concrete increases first and then decreases with the increase of replacement rate.When the replacement rate is 30%,the maximum compressive strength is 12.48 MPa.Then,carbonation reclaimed aggregate and molded test blocks were carried out.It was found that when CO_(2)concentration was 99%,the compressive strength of recycled aggregate carbonation for 7 days reached 11.4 MPa,which was 32.56% higher than that of untreated test blocks.Finally,the modified Furnas model was used to study graded aggregate,and it was found that the strength and porosity of test blocks are best balanced when the proportion of recycled small aggregate is 10% to 20%.Finally,an engineering application test of recycled aggregate concrete was carried out and good results were obtained.The research results can provide a theoretical basis for the popularization and application of recycled aggregate concrete.