不同类别再生混凝土抗冻性能的试验研究

混凝土抗冻性能是评价混凝土耐久性的重要指标之一,通过添加矿物掺合料、聚丙烯纤维对Ⅱ、Ⅲ类再生混凝土进行强化处理,综合考虑基本力学性能后,挑选最优组进行抗冻性试验研究,结果表明:(1)Ⅱ、Ⅲ类再生混凝土抗冻性较差,掺加矿物掺合料以及复掺聚丙烯纤维都可以改善Ⅱ、Ⅲ类再生混凝土抗冻性。(2)由于不同类别再生骨料的性能之间存在差异,质量损失率不能很好的反映不同类别再生混凝土之间抗冻性的优劣,不建议质量损失率作为评判再生混凝土抗冻性的指标。(3)损伤度的试验结果进行非线性拟合,得到累积损坏的指数模型D=aebN,模型拟合方程具有很高的精确度。

Experimental study on frost resistance of different types of recycled concrete

Frost resistance of concrete performance is one of the important indexes to evaluate the durability of concrete,by adding mineral admixtures and polypropylene fiber on theⅡ、Ⅲkind of recycled concrete reinforcement processing,considering the basic mechanical properties,select the optimal set of frost resistance experiment study,the results show that(1)Ⅱ、Ⅲrecycled concrete frost resistance is poorer,adding mineral admixtures and double mixing polypropylene fibre can improveⅡ、Ⅲrecycled concrete frost resistance.(2)Due to the differences in the performance of different types of recycled aggregate,the mass loss rate cannot well reflect the advantages and disadvantages of frost resistance between different types of recycled concrete.Therefore,it does not recommend the mass loss rate as an indicator to evaluate the frost resistance of recycled concrete.(3)The test results of damage degree are non-linear fitted to obtain the exponential model D=aeb Nof cumulative damage,the model fitting equation has high accuracy.