Effect of additives on the strength of alkali activated slag/fly ash cementitious system
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.Micro-scopic analysis shows that additives can promote the formation of C-(A)-S-H gel,and make the microstructure tend to densify.
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维普
