Study The Concrete Aggregate Alkali Reactivitgies In Xian District

The definition category and expansion Principle of alkali-aggregate reaction (abbr.AAR in the following) is detoilly descruiked in the thesis.The three conditions for the reaction of AAR,the main technigue measures to restrain the AAR is also explained in this article.Commenting and the major advantages disatv and effectiveress of eight methods obefiniting concrete aggregate alkali reactivcity at home and abroad at present.Raised the purpose,significancs and main contants to study the concrete aggregate alkali reactivitgies in Xian district.According to the specific distribution of concrete aggregate sources in Xian district .It had definated in the thesis that :taking the river gravel (crushed stone ) river sand in the rivers of BaHe, JingHe, WeiHe, ChanHe etc. AS the researching objects;taking the classic ASTMC295 《Concrete Aggragate Petrographic Checking Gaicle》 CECS48 《Sand Stone Alkali Reactivity Quick Test Method》 and ASTMC1260 《Aggregate Latent Alkali Reactive Testing method》 as the main measures .The paper made a systematic and detail research. Based on the alkali reactive in the main materials of sand ,gravel,aggregate used to produce concrete. Production in Xian district.The research judged by collodal mortar expansion rate got from the process of checking sand, gravel aggregate in a fin definited alkali.circumstances while in different temperature, pressure, moisture circumstances.Also through the lime stone querry inspection,micro obtic photos to search for the theoretic explaination which is correcspending with the measured colloidal mortar aggregate rate.As the result of research ,the major concrete aggregate in Xian district is the river gravel and guarts sand which is with very complicated composition.Althougu the reactive mineral materials are exisled in the river gravel in BaHe River and so on.In the BaHe gravel the trace opal is exisled while opal is normally contented in mica guarts rock,the flint stripes in JingHe River gravel ,thr micro concrete mortar expansion rate of gravel aggregate is not in the range of the reactive aggregate .So the researed concrete aggragate is the non-alkali reactive. The result of the research is agree with the actual situation in Xian district-the concrete construction ect.never came across the aikali aggregate reaction 100 years ago.The recated rationalifation proposal are provised in the thesis arct.