Influences of Additives on Alkali-Activated Cementitious Materials Drying Shrinkage Performance
In order to further improve the shrinkage characteristics of alkali-activated cementitious materials,the effects of single-doped organic shrinkage reducing agents(polyethylene glycol and latex)and inorganic expansion agents(CaO,MgO and gypsum)on hydration products composition,pore structure and shrinkage characteristics of alkali-activated slag fly ash(AASF)system were explored.The results show that among all the additives,polyethylene glycol has the most significant shrinkage reduction effect.The 91 d drying shrinkage of AASF samples with 1％(mass fraction)polyethylene glycol is only 1 683 με,which is 29.7％lower than that of control group,mainly due to the significant coarsening of pore structure.Polyethylene glycol and latex have a certain negative impact on the compressive strength of AASF,mainly due to the decrease of hydration reaction and the increase of overall porosity.The shrinkage compensation effect of three expansion agents in AASF system is not strong,but there is a significant increase in flexural strength.
万方数据
维普
