基于地聚合物再生混凝土的道路基层结构力学性能研究

Study on Mechanical Properties of Road Base Structure Based on Geopolymer Recycled Concrete

地聚合物再生混凝土是将粉煤灰、氢氧化钠溶液及水玻璃的混合物作为胶凝材料,将废弃混凝土破碎后重新筛分作为集料,按照一定的配合比浇筑成新的混凝土材料。再生混凝土材料由于其组成材料的质量难以控制,用于道路基层时必须经过严格的试验验证。利用试验的方法,得到了再生混凝土不同胶凝材料掺量下7、28、90 d的抗压强度,90 d龄期的劈裂强度和90 d龄期的无侧限抗压回弹模量3个力学指标,通过3个指标分析,胶凝材料掺量在5%~7%时,再生混凝土材料的力学性能符合相关规范要求。

Geopolymer recycled concrete is a mixture of fly ash,sodium hydroxide solution and sodium silicate as cementitious material.After crushing waste concrete,it is re-screened as aggregate and poured into new concrete material according to a certain mix ratio.The quality of recycled concrete is difficult to control,so it must be tested strictly when it is used in road base.In this paper,the compressive strength of recycled concrete in 7 days,28 days and 90 days,the splitting strength in 90 days and the unconfined compressive resilience modulus in 0 days are obtained by means of experiments.Through the analysis of the three indexes,the mechanics of recycled concrete is obtained when the content of cementitious material is 5%~7%.The performance meets the requirements of relevant specifications.