低品质再生骨料强化技术研究

Study on Strengthening Technology of Low Quality Recycled Aggregate

再生骨料资源化利用过程中,存在模数低、亚甲基蓝值过高、孔隙率高、抗冻融性差等缺点。为此,模拟工厂应用场景下的机械拌合过程,将不同强化剂混合到低品质再生细骨料中;强化剂会附着在骨料表面与粉体聚集,表现为级配中细颗粒级配向粗颗粒级配迁移,模数增大;干燥后,骨料表面由强化剂形成的疏水层会阻断部分骨料间隙,利于降低骨料的吸水率,提高骨料的抗冻融性能。研究结果表明,骨料中的超细粉末经强化剂强化后形成一种具有强度的晶体,可降低亚甲蓝值。将经强化的再生骨料应用于干混砂浆中,能有效改善砂浆的各项性能,因此具备实际应用价值。

In the process of recycled aggregate resource utilization,there are shortcomings such as low modulus,high methylene blue value,high porosity,and poor freeze-thaw resistance.To this end,the mechanical mixing process under the application scenario of the factory is simulated,and different reinforcers are mixed into low-quality regenerated fine aggregates;the reinforcing agent will be attached to the aggregate surface and the powder aggregate,which is manifested as the migration of fine particles in the gradation to the coarse particle gradation,and the modulus increases;after drying,the hydrophobic layer formed by the reinforcing agent on the aggregate surface will block part of the aggregate gap,which is conducive to reducing the water absorption rate of the aggregate and improving the anti-freeze-thaw performance of the aggregate.The results show that the ultrafine powder in the aggregate is strengthened by the intensifier to form a crystal with strength,which can reduce the methylene blue value.The application of reinforced recycled aggregate to dry-mix mortar can effectively improve the properties of mortar,so it has practical application value.