Study Of Several Kinds Of Volcanic Ash Activity And Reaction Degree

With the rapid development of human society, cement has become one of the mostmain gelled materials of our social infrastructure. It is well known that the cement isartificial materials, production process uses large amounts of energy and emissionshuge amount of harmful gas, pollute the environment. In the long term consideration,the cement industry is a kind of unsustainable development industry. Based on theabove facts, find materials to replace or partly replace cement for social construction,will produce a great social benefits, economic benefit and environmental benefit.Volcanic rock is cooling from the molten magma that volcanic eruption，its maincomposition is SiO2and Al2O3. People has been found that volcanic rock has someash activity, grinding into powder and mixed into cement, the active SiO2or activeSiO2+Al2O3can react with Ca (OH)2, and generate relatively low alkaline hydratedproduct, show some volcanic activity. Investigation shows that the volcanic rocks arewidely distributed, abundant, is one of the ideal cement mineral admixture.This article selects several representative volcanic rock samples from jiang xiprovince, analyzed the chemical components of its, using cement mortar strengthratio method, K alpha value method and XRD estimates method to quantitativeanalysis the volcanic activity of the sample. Using hydrochloric acid dissolutionmethod to quantitative analysis of the reaction degree of volcanic rocks in the cement,established the relationship between reaction degree and content and curing age.Using thermo gravimetric analysis means to study the content of chemical combinedwater and Ca (OH)2, quantitative analysis the tendency that chemical combined waterand Ca (OH)2content with the content and the age.The results showed that three kinds of active evaluation method can be mutualauthentication very well; all kinds of methods to analyze the results showed that thevolcanic activity of JX was the best. In three ways, mortar strength ratio method toevaluate the volcanic ash activity takes longer, will make the28d above. Active ratemethod is reliable, the result of the experiment method is improved, with residual quantity method instead of chemical method, not only the operation is simple, and thetest result and chemical test results with good correlation, this paper adopts themethod of residual is not reported in the literature. XRD estimation method is simpleand intuitive, XRD analysis, and is a more convenient and quick evaluation method ofvolcanic ash activity.Using hydrochloric acid dissolution method to quantitative analysis of the reactiondegree of volcanic rocks in the cement, With content increased from10%to40%,with the prolongation of the age, the reaction degree increases gradually, the biggerthe dosage, the more obvious this trend. In content increased gradually in the process,JX sample reaction degree at different curing age has always been the biggest, JXBsamples of each age is always the smallest, the other four samples between the two.There have a good linear relation between the change tendency of the chemicallycombined water content and reaction degree, use the reaction degree of YQ and XNand combined water content to fit, the correlation coefficient R was0.902and0.902,fully shows the close relationship between the reaction degree of the volcanic rocks incement paste and the total combined water content. Analyze the reason, that thehigher the reaction degree, the more volcanic rock powder participate in the reaction,the more hydration products are formation, so with the increase of reaction degree, themore the chemically combined water content.