外加组分对碱激发矿渣/粉煤灰胶凝体系强度影响研究

Effect of additives on the strength of alkali activated slag/fly ash cementitious system

采用碳酸钠、硫酸钠、硅酸钠、氯化钙、甲酸钙来提升Ca(OH)_(2)-Mg(OH)_(2)复合碱激发矿渣/粉煤灰体系(CMSF)的力学强度,通过X射线衍射、热重分析以及扫描电镜分析了材料的微观产物及结构。结果表明,与空白对照组相比,当碳酸钠掺量为8%时,CMSF各龄期抗压强度提高了80%左右;当硫酸钠掺量为4%时,CMSF的3、7 d抗压强度分别提高了79%和90%;当硅酸钠掺量为10%时,CMSF的3、7、28 d抗压强度分别提高了195%、329%、215%;当氯化钙掺量为10%时,CMSF的3、7、28 d抗压强度分别提高了375%、402%、248%;当甲酸钙掺量为2%时,CMSF的3、7、28 d抗压强度分别提高了312%、354%、233%。外加组分会促进C-(A)-S-H凝胶的形成,使微观结构更加致密。

Effects of sodium carbonate,sodium sulfate,sodium silicate,calcium chloride,and calcium formate on the mechanical strength of the Ca(OH)_(2)-Mg(OH)_(2)composite alkali activated slag/fly ash system was studied.The micro-products and structure of the materials were analyzed by X-ray diffraction,thermogravimetric analysis,and scanning electron microscopy.The results showed that compared with the control group without additive,when the sodium carbonate content was 8%,the compressive strength of CMSF at various ages increased by about 80%;When the dosage of sodium sulfate is 4%,the compressive strength of CMSF at 3 and 7 days increased by 79%and 90%,respectively;When the dosage of sodium silicate is 10%,the compressive strength of CMSF at 3,7,and 28 days increased by 195%,329%,and 215%,respectively;When the content of calcium chloride is 10%,the compressive strength of CMSF at 3,7,and 28 days increased by 375%,402%,and 248%,respectively;When the content of calcium formate is 2%,the compressive strength of CMSF at 3,7,and 28 days increased by 312%,354%,and 233%,respectively.Microscopic analysis shows that additives can promote the formation of C-(A)-S-H gel,and make the microstructure tend to densify.