Study on alkali activity evaluation of mountain tunnel slag and inhibition measures of alkali-aggregate reaction
In this paper,the alkali activity of a high-speed tunnel slag is determined,and the inhibition measures of alkali-ag-gregate reaction are put forward from two aspects of compactness and hydrophobicity,and the inhibition effect is comprehensively e-valuated by expansion rate and strength.the inhibition mechanism was explored from water absorption and alkali content in pore solution.The results show that cave slag aggregate belongs to high alkali activity-silicate aggregate,which has the risk of alkali ag-gregate reaction;controlling fly ash not less than 30%can effectively restrain the alkali aggregate reaction of cave slag;using 10%~12%RMA nano-preservative or 2.5%~7.5%TIA anti-corrosion inhibitor to optimize 30%fly ash can have both strength guarantee and alkali aggregate reaction inhibition.Single addition of fly ash,double addition of fly ash and nano-preservative RMA can in-hibit alkali-aggregate reaction mainly by reducing the free alkali ions in pore solution,while double-mixing fly ash and TIA anti-corrosion inhibitor can inhibit alkali-aggregate reaction mainly by reducing alkali ion and water absorption.