垃圾焚烧飞灰-废玻璃地聚合物砌筑砂浆的制备与性能研究

Preparation and properties of waste incineration fly ash-waste glass geopolymer masonry mortar

以垃圾焚烧飞灰、废玻璃粉、粉煤灰为主要原料,采用碱激发技术制备了地聚合物砌筑砂浆。通过早期试验确定了净浆中飞灰的掺量,再以玻璃粉掺量、NaOH浓度、碱液比和液固比为因子设计正交试验,通过测试地聚合物砌筑砂浆的工作性能、力学性能、重金属浸出毒性,得出了砂浆的最佳配合比;并进行了微观分析,揭示了强度增强机理。结果表明,当垃圾焚烧飞灰掺量为30%,粉煤灰掺量为70%,玻璃粉替代砂率为30%时,砌筑砂浆的抗压强度达到24.3 MPa,保水性、稠度符合JGJ/T 98—2010《砌筑砂浆配合比设计规程》要求,且重金属浸出毒性小。结合SEM-EDS和XRD分析表明,样品中生成的C-S-H和N-A-S-H凝胶,有利于砂浆强度提高,全试验掺量范围内玻璃粉掺量越高,样品结构越紧密。

Using waste incineration fly ash,glass powder and fly ash as the main raw materials,the geopolymer masonry mortar was prepared by using alkali excitation technology.The amount of fly ash in the net pulp was determined by early tests,Orthogonal experiments were designed with glass particle content,NaOH concentration,lye ratio and liquid-solid ratio as factors.By testing the working performance,mechanical properties and heavy metal leaching toxicity of geopolymer masonry mortar,the optimal mixing ratio of mortar was obtained;and microscopic analysis was carried out to reveal the strength enhancement mechanism.The results show that when the content of waste incineration fly ash is 30%,the content of fly ash is 70%,and the ratio of glass powder to replace sand is 30%,the compressive strength of the sample reaches 24.3 MPa,the water retention and consistency meet the JGJ/T 98—2011"Masonry Mortar Mix Ratio Design Regulations",and the leaching toxicity of heavy metals is small.Combined with SEM-EDS and XRD analysis,it is shown that the C-S-H and N-A-S-H gels generated in the samples are beneficial to the increase of the strength of the mortar,and the structure of the samples is more compact with the increase of glass powder content.