全固废胶凝材料协同轮胎颗粒固化渣土的力学性能与微观机理研究OA

The large-scale stockpiling of construction waste and industrial solid waste poses a severe threat to the ecological environment,necessitating the development of economically and efficient path-ways for resource utilisation.In order to validate the efficacy of industrial solid waste as a solidification agent,this study employs a slag-alkali slag-phosphogypsum(SAP)solid waste system in conjunction with waste tire particles(TPs)for the synergistic solidification of construction waste.The strength of the resulting solidified material is compared with that of conventional cement-stabilised soil.Response surface experiments determined the optimal ratio of SAP solidification agent as m(slag)∶m(alkali slag)∶m(phosphogypsum)=16.2%∶3.8%∶4.6%.On this basis,2.5%,5%and 7.5%of the tire particles were added to investigate their impact on solidified soil properties.It indicates that the SAP-so-lidified soil exhibits unconfined compressive strengths of 3 412 kPa and 11 893 kPa at 7 days and 28 days respectively,with water stability coefficients of 0.85 and 0.90.A tire particle content of 2.5%can in-crease soil strength,comparing to cement-stabilized soil.However,if the proportion exceeds 5%,both the strength and stability of solidfied soil are decline.Microscopic analysis reveals that the SAP system generates a calcium silicate hydrate(C-S-H)gel with spatial network structure and acicular-rod-shaped ettringite(AFt).Excessive tire particle content can disrupt this structure.This research demonstrates that SAP solidification agent can effectively substitute cement,and incorporating a small amount of tire particles enhances soil stabilisation strength.This provides a viable pathway for resource utilisation of industrial solid waste and disused tires in soil stabilisation applications.