Research On The Investagetion And Inhibition For Alkali-activity Of Aggregates In Urumqi Region

In this paper , at first, Alkali-activity of aggregates which used in Xinjiang Urumqi region are studied, research showed that the essential rocks of aggregates belong to volcanic-tuff and esite-tuff. In which the composition are glass shard, detritus or cryptocrystalline of silica, they are all belong to Alkali-activity rocks in sedimentary rock. The result of mortar expanding rate also showed that aggregates of main areas in Urumqi have Alkali-activity.The Second selecting this Alkali-activity aggregate, the inhibition effect of mineral admixture to the mortar expanding rate has been researched by ASTM C1260 method. Also under same amount of mineral admixture, the inhibition effect got by mixing only fly ash, only zeolite powder and fly ash with zeolite powder respectively. From the result, it was showed that mineral admixture under range from 10% to 50%, with the amount increasing of fly ash or zeolite powder, the mortar expanding rate was decreased. The results also showed that compared mixing fly ash and zeolite powder with only fly ash or only zeolite powder, the inhibition effect of mixing fly ash and zeolite is better than any only one under the condition of total amount is 30% with autoclave 24h and 40% with autoclave 6h; and the mortar expanding rate is zero under the condition of total amount is 30%( zeolite powder) +20%( fly ash) with autoclave 6h.Amount of fly ash under range from 10% to 50%, the relationship between autoclave and mortar expanding rate were displayed linearity, after fitting with least-square method, the linear relationship formation has been gotten with degree (0.9541-0.9868) of correlation.At end, according to the interaction principles of mineral admixture, analyzed its chemical composition, structure characteristics and other relevant materials for the suit Urumqi's aggregates-applied condition.