摘要
为探究碱激发剂种类与掺量对再生微粉砂浆性能的影响及其作用机理,将NaOH、Ca(OH)_(2)、Na_(2)SiO_(3)·9H_(2)O等3种碱激发剂,分别以2%、3.5%、5%、6.5%的掺量制备再生微粉砂浆,对砂浆的力学性能、微观形貌、孔隙变化及水化特性进行研究。结果表明:掺量分别为6.5%、2%的Ca(OH)_(2)、Na_(2)SiO_(3)·9H_(2)O表现出更优的抗压性能,抗压强度分别提升10.8%、3.8%;NaOH在掺量为2%时,抗压强度损失最小。Ca(OH)_(2)能降低砂浆介孔、中孔、大孔孔隙率,促进后期水泥水化,第二放热峰提前。NaOH能减小介孔孔径,可加速早期水化,但无明显的第二放热峰。Na_(2)SiO_(3)·9H_(2)O可减小介孔孔径,第一、第二放热峰均提前。
To investigate the influence and underlying mechanisms of alkali activator type and dosage on the properties of recycled micro-powder mortar,three alkali activators NaOH,Ca(OH)_(2),and Na_(2)SiO_(3)·9H_(2)O were used at dosages of 2%,3.5%,5%,and 6.5%to prepare recycled micro-powder mortar.The mechanical properties,micromorphology,pore structure change,and hydration characteristics of the mortar were examined.The results showed that Ca(OH)_(2)and Na_(2)SiO_(3)·9H_(2)O exhibited superior compressive performance at dosages of 6.5%and 2%,respectively,increasing compressive strength by 10.8%and 3.8%.In the case of NaOH,the compressive strength loss was smallest when its dosage was 2%.Ca(OH)_(2)reduced the porosity of mesopores,medium pores,and macropores,promoted later-age cement hydration,and advanced the second exothermic peak.NaOH decreased the mesopore size and accelerated early-age hydration,with no distinct second exothermic peak observed.Na_(2)SiO_(3)·9H_(2)O reduced the mesopore size and advanced both the first and second exothermic peaks.Studying the influence of alkali activation on properties of recycled micro-powder mortar can provide a reference for the application of recycled micro-powder concrete.
作者
陈登海
李滢
李嘉琛
CHEN Denghai;LI Ying;LI Jiachen(School of Civil Engineering and Water Resources,Qinghai University,Xining 810016,China;QinghaiProvince Key Laboratory of Building Energy-saving Materials and Engineering Safety,Xining 810016,China)
出处
《青海大学学报》
2025年第6期72-80,共9页
Journal of Qinghai University
基金
青海省科学技术厅项目(2023-ZJ-725)。
关键词
碱激发
再生微粉
水泥砂浆
力学表征
微观孔结构
水化特性
Alkali activation
Recycled micro-powder
Cement mortar
Mechanical characterization
Microscopic pore structure
Hydration characteristics
