Study on the Mechanical Properties of Slag-Based Cement Paste under Coupled Excitation
Slag,a byproduct of coal combustion,occupies significant land area when piled in large quantities,leading to land resources wasteage and landscape degradation.Rich in silica,alumina and other active substances,slag is often used as mineral admixtures in concrete to enhance its performance.However,research on slag-based cementitious materials is still in its early stages,particularly in areas such as excitation pathways,factors influencing mechanical properties,and microstructural evolution.Therefore,this paper investigates the mechanical properties and microstructural evolution of slag-based cement mortar under coupled mechanical-chemical excitation.Firstly,the influence of grinding parameters on the particle size distribution of slag is discussed.Then,the effects of coupled excitation parameters and curing age on the compressive and flexural strength and mechanical activity of slag-based cement mortar are investigated.Finally,SEM,XRD and FTIR are used to study the changes in hydration products,functional groups,and microstructures of slag-based cement paste,aiming to elucidate the mechanism by which coupled excitation pathways influence mechanical properties.Under optimal coupled excitation conditions,the compressive and flexural strengths of slag-based cement paste,after 28 d of standard curing,increased by 19.8％and 29.1％,respectively,compared to the benchmark cement mortar.The contents of type Ⅰ and type Ⅱ C-S-H gel phases increased by 71.4％and 58.3％,respectively,compared to the benchmark cement mortar.Indicating more C-S-H gel formation.The optimal conditions were a material ratio of 18:1,ball milling time of 20 min,total alkali exciter dosage of 1.5％,and a molar ratio of Ca(OH)2 and Na2(SO)4 of 2:3.This coupled excitation promotes the hydration reaction of the cementitious materials,enhances C-S-H gel generation and forms a denser microstructure,thereby significantly improving the mechanical activity and regeneration efficiency of slag.This study offers new insignts and methods for preparing low-carbon,environmentally friendly and sustainable cementitious materials.
slagcement net pastemechanical grindingcoupled excitationmechanical propertiesmicrostructureparticle size distributionactivity
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维普
