Research On The Influence Of Oil Extracts On The Shrinkage And Strength Of Alkali-Activated Slag Paste

Alkali-activated cementitious material is expected to be a substitute for cement cementitious material,but its shortcomings of excessive drying shrinkage and selfshrinkage need be solved.Some researchers have proved the shrinkage reduction effect of waste oil on alkali slag,but have not studied in depth whether there are adverse components and which components are more effective.This topic will research the stearic acid,oleic acid and glycerin net of alkali excitation slag slurry shrinkage properties,mechanical properties and the influence of other related performance,and through the micro test analysis the reasons of the change of macro,promotes the application of alkali excitation gelled material to provide theoretical basis,and provides a way for the reuse of food and beverage and industrial wastes.Specific research contents are as follows:Under the conditions of water-binder ratio of 0.35,alkali concentration of 3%and sodium silicate modulus of 1.0,9 groups of mixture ratios were designed with the type and amount of admixtures as variables,and the dry shrinkage and autoshrinkage of each group were measured by contact method.The results showed that: Glycerin is unfavorable to the shrinkage of alkaline slag slurry,while both stearic acid and oleic acid can reduce its shrinkage,and the effect of reducing autoshrinkage is more obvious.The shrinkage reduction effect of oleic acid is better than that of stearic acid,and the shrinkage reduction effect of adding stearic acid and oleic acid at the same time is close to that of adding oleic acid alone.After the removal of the two groups with glycerin,the mechanical properties of the remaining seven groups of specimens were tested,and the flexural strength and compressive strength of each group at different ages were measured.The results showed that: The addition of stearic acid and oleic acid will reduce the net pulp strength,especially early flexural strength,stearic acid oleic acid compared to the strength of the wreck a smaller,stearic acid and oleic acid at the same time add oleic acid increased compared to the strength of the individual,but along with the age growth,between groups of strength to recover,after 90 d groups of compressive strength close to the control group.Under the same mixture ratio,the fluidity,setting time,density,water absorption and carbonation depth of 7 groups of specimens were tested.The results showed that the mixed addition of stearic acid and oleic acid could make up for each other’s shortcomings and improve each performance compared with the separate addition.By MIP mercury injection test and SEM test to join shrinkage-reducing agent before and after the microcosmic performance was analyzed,and the results show that the addition of stearic acid reduced the number of internal porosity and mesoporous,and the addition of oleic acid increased the internal porosity,but improve the pore size distribution,increase the number of the big hole,the effect on the pore structure is different.