碱-矿渣-偏高岭土基地聚物干燥收缩研究

Study on the drying shrinkage of alkali-slag-metakaolin based geopolymer

碱-矿渣-偏高岭土基(ASM)地聚物具有可常温固化、快凝早强、耐腐蚀等特点,但其收缩率较大,限制了工程领域中的广泛应用。研究了激发剂模数、激发剂浓度及液固比对ASM地聚物干缩性能的影响机制。结果表明:ASM地聚物的干缩率随着激发剂模数的增大而增大,随着激发剂浓度的增大而减小,随着液固比的增大而增大。在碱激发剂作用下,ASM地聚物发生了地质聚合反应和矿渣水化反应,当体系中以矿渣的水化反应为主导反应时,内部结构产生更多的孔隙及更大的孔径,且硬化浆体疏松开裂,干缩率较大。

Alkali-slag-metakaolin-based(ASM)geopolymers have the characteristics of solidification at room temperature,fast setting and early strength,corrosion resistance,etc.,but their shrinkage rate is large,which limits their wide application in the engineering field.The influence mechanism of activator modulus,activator concentration and liquid-solid ratio on the dry shrinkage performance of ASM geopolymers was studied.The results show that the dry shrinkage rate of ASM geopolymers increases with the increase of activator modulus,decreases with the increase of activator concentration,and increases with the increase of liquid-solid ratio.Under the action of alkali activator,the geological polymerization reaction and slag hydration reaction occurred in ASM geopolymers,and when the hydration reaction of slag was the dominant reaction in the system,the internal structure produced more pores and larger pore sizes,and the hardened slurry was loose and cracked,and the dry shrinkage rate was larger.