Research On Alkali-aggregate Reaction Of Dam Concrete

The alkali-aggregate reaction is called the"cancer"of concrete,which seriously affects the safety and durability of concrete engineering.Therefore,one of the important topics of engineering treatment projects is study the damage mechanism of alkali-aggregate reaction on concrete used to improve the durability of concrete.This paper takes the Longtanqing Debris Flow Gully Treatment Project in Huaning County,Yunnan Province as the research object.,and through the alkali-aggregate reaction inhibition test under different conditions.The regression analysis and trend surface analysis of the experimental data obtained by MATLAB software provide a scientific theoretical support for the design and construction of the treatment project.The specific conclusions are as follows:（1）There is a highly nonlinear negative correlation between the content of fly ash and the expansion rate of concrete specimen.The higher the amount of fly ash,the lower the expansion rate of the concrete specimens;There is a highly nonlinear positive correlation between curing age and expansion rate of concrete specimen.The longer the curing period,the higher the expansion rate of the concrete specimen;when the fly ash content is less than 20%,the cement alkali content has a smaller effect on the expansion rate of the concrete specimen.When the fly ash content is≥20%,the alkali content of the cement is positively correlated with the expansion rate of the concrete specimen.The higher the alkali content,the higher the expansion rate of the concrete specimen;（2）Use regression analysis and trend surface analysis to analyze the test data.The regression equations of the fly ash content under different alkali content,the expansion rate of the concrete specimen,the curing age and the expansion rate of the concrete specimen are respectively obtained:z=F（）=(6·⁽（7）+(8;Obtain the regression equations of fly ash content,curing age and expansion rate of concrete specimens under different alkali content:z=F（x,y）=p₀₀+p₁₀+p₀₁y+p₂₀²+p₁₁+p₀₂²+p₃₀³+p₂₁²+p₁₂y²+p₀₃y³+p₃₁³y+p₂₂²y²+p₁₃y³+p₀₄y⁴。（3）From the perspective of economy,safety and effectiveness,two engineering measures to inhibit the alkali-aggregate reaction are proposed:reduce the alkali content of concrete and use Class I F fly ash with a high content of 35%as concrete admixtures.