Study On Effects Of Materials With Multiple Admixtures On Acid Corrosion Resistance Of Cement Based Materials

With the rapid development of domestic infrastructure projects,the durability of concrete engineering has attracted great attention in the engineering field.Acid corrosion of concrete structures is one of the main reasons affecting durability.It has gradually become a major technical problem in the engineering field.Due to its severe damage and complex mechanism,it is urgent to carry out systematic research on mechanism and application.The acid corrosion of concrete is mainly due to the reaction of corrosive acid and the main hydration products of calcium hydroxide,calcium aluminate etc,produced in the hydration process of cement,which affects the internal structure and performance of concrete.This paper mainly carries out the research on the concrete raw material,so as to improve the acid resistance performance of concrete.Taking polypropylene fiber,fly ash,mineral powder and sodium silicate as the main research objects,the research systematically tested and studied the effects of multi-doped compound materials on the acid corrosion resistance of cement base materials through indoor experiments and Data analysis,Matlab software fitting analysis.The findings and conclusions are as follows:(1)The rate of corrosion of cement gel sand in strong acidic medium is faster than the rate of corrosion in weak acidic medium.(2)With the amount of fly ash mixed with 15 % to 30 %,the cement gel sand has a good acid resistance.(3)With the amount of mineral powder mixed with 15 % to 30 %,the weak acid resistance performance of cement gel sand is good,but it can not improve the strong acid resistance of cement gel sand.(4)When the mixture of fly ash and mineral powder is mixed with a certain amount,the amount of sodium silicate mixed in 1.5 % ~ 3.0 %,Considering the effect of sodium silicate on strength,the amount of sodium silicate added is recommended to be within 1.5 %.Cement gel sand has better acid resistance.The test shows that the better mixing ratio is fly ash:mineral powder:sodium silicate = 15 %: 30 %: 1.5 %.(5)The study of microscopic pore distribution by Mercury pressing shows that the addition of fly ash and mineral powder can reduce the pores inside cement gel sand.With the help of sodium silicate which is the action of alkali excitation agent,it produces secondary hydration reaction between the multi-doped compound and the cement hydration product and a dense hydrosilicate calcium gel,then alters the pore structure of the cement gel sand which can effectively prevent the infiltration of acid materials from the outside world,and improve the acid resistance of the concrete.