地聚物多因素协同作用下凝结与硬化特性分析OA

To achieve high-value utilization of bulk industrial solid wastes,this study investigated the relationship and mechanism between the CaO/(SiO2+Al2O3)molar ratio and multifactorial parameters in geopolymers.Blast furnace slag(high-calcium precursor)and fly ash(low-calcium precursor)were activated with sodium silicate solution as an alkaline activator to synthesize green,high-strength,and low-carbon geopolymer binders.Orthogonal experiments were conducted to evaluate the effects of CaO/(SiO2+Al2O3)molar ratio,curing age,water-to-solid ratio,alkaline activator dosage,and modulus on compressive strength and setting time.Microstructural and hydration mechanisms were analyzed using TG-DTG,XRD,and SEM.Results indicated that the CaO/(SiO2+Al2O3)molar ratio significantly enhanced early strength:when the ratio increased from 0.18 to 0.41,the 7-day compressive strength rose from 8.99 to 17.54 MPa,respectively,with an increase of 95.11％.Hydration products evolved from single N-A-S-H to coexisting N-A-S-H,C-(A)-S-H,and C-A-H,which improved structural compactness.Setting time was governed mainly by the CaO/(SiO2+Al2O3)molar ratio and water-to-solid ratio,showing negative and positive correlations,respectively.Regression equations were established to predict 28-day compressive strength,initial and final setting times.These findings provide useful insights into the development of geopolymer binders for sustainable soil stabilization.