Abstract:Lithology and alkali activity of low grade metamorphic rock aggregates in different regions of southeastern part of Guizhou province were analyzed, the influence of total alkali contents on alkali aggregate reaction(AAR) was analyzed, and the optimum proportion of low grade metamorphic rock aggregates inhibition technology was investigated by orthogonal test. Results indicate that the saturated compressive strength of the low grade metamorphic rock aggregates is more discrete, and theses samples in each group are silicate rock aggregates. The 14d expansion rate of the mortar specimens is more than 01%, indicating the potential harm from alkali silicate reaction(ASR). The inhibition of fly ash on AAR is obvious, and the expansion rate of 14d in each group has been reduced, and most of them do not exceed 003%. The greater the total alkali content of concretes, the faster the AAR, the longer the reaction period and the higher the expansion rate. The alkali content should be limited in 1%. From SEM EDS, comparing the specimen without AAR, it has been seen that a honeycomb like silicate gel product is formed on the aggregate surface, the aggregate surface has fine cracks, and the Si and Na elements are enriched in the specimen in which the alkali aggregate reaction occurred.