| Waste glass is an important part of the municipal solid waste, the re-use of wasteglass can protect the environment, reduce the waste of land resources, and also cansave energy and resources, achieve environmental and economic benefits win-win.Waste glass is used for the production of concrete is one of the important means ofdisposing it, Europe and the United States and other developed countries have done alot of research on it and has formed a complete industrial chain, but research in thisarea started late at home. This project will study the activity of waste glass powder todetermine suitability for use as concrete admixture.Study activation effect of physicalactivation, chemical activation, hydrothermal activation, composite activation onwaste glass powder.Ten different fineness glass powder are obtained fromgreen,colorless,brown waste glass powder are gridding different time,and use laserparticle size analyzer and the measured specific surface areadetermine its finenesscharacteristic parameters such as particle size distribution and specific surfacearea.Then conducting activity provocation test and the mortar strength testing areconducted in accordance with GB/T17671-1999(ISO method)“Method of testingcements-Determination of strengthâ€. Replacement of cement with glass powderaccording to the same amount of30%,and measuring comprehensive strength ofcontrol specimens and specimens which doped with glass powder,and activity indexare calculated reference GB/T1596-2005“Fly ash used for cement and concreteâ€,evaluating the level of activity of glass powder, This research are as follows:(1)Physical activation: calculating particle size distribution fractal dimension,and studing the relationship between activity index and particle size distributionfractal dimension,and relationship between activity index and color;(2)Chemical activation:sodium sulfate (Na2SO4)and slaked lime (Ca(OH)2) arecarried at3%,4%,5%of ash and added to hydration system of glass powder, studingrelationship between activation effect and agent dosage,and comparing activation effect of two different exciting agent,studing the effect of activation of agent complexdoped with2%Na2SO4+2%Ca(OH)2;(3)Hydrothermal activation: green, colorless, brown waste glass powder whichgridding35min are hydrothermal treatment2h,4h,6h under125°C and1.1Mpastuding the relationship between treatment time and activity;(4)Composite activation:physical-chemical-hydrothermal activation are based onsingle activation,obtain ideal composite excitation parameters through single singleexcitation parameter;(5) The microscopic mechanism analysis: micro excitation mechanism of theactivity of waste glass powder are analysed by scanning electron microscopy (SEM)and mercury intrusion test.The experiment has been the following main conclusions:(1) The pretreated waste glass powder for cement mineral admixture is feasibleafter chemical, hydrothermal, composite pretreatment;(2)The effect of activation in order from best to worst is composite activation,hydrothermal activation, chemical activation, physical activation;(3)Brown glass powder appears to be highest activity, followed by green, activityof uncolored glass powder is lowest when fractal dimension is near;(4)Fractal dimension of waste glass partical size distribution is a comprehensiveparameter of particle characteristics, which can effectively characterize the particlesize characteristics of waste glass powder;(5) With increasing milling time activity index of waste glass powder is not linearincrease, while there is an optimum grinding time,in this study the most reasonablegrinding time is35min;(6) When waste glass powder is used as mineral admixtures, there is an optimumparticle size range, the activate is best when paticle size is between6.414~20.70μm,however the activate is lowest when particle size of waste glass powder is less than3.412μm;(7)Mixed with right amount of chemical activator can effectively stimulate thepozzolanic activity of waste glass powder,activity index of waste glass powder increasing with dosage of sodium(Na2SO4),slake lime(Ca(OH)2)increase from3%to4%,however it decreasing with dosage of sodium(Na2SO4),slake lime (Ca(OH)2)increase from4%to5%;(8)Excitation of Na2SO4is dual excitation of alkali and sulfates, and theactivation effect is better than Ca(OH)2;(9)Activate of waste glass powder increased with the age,it grow rapidly in earlyage but grow slowly in later age;(10)Green, colorless, brown waste glass powder activity index grows with thegrowth of the high temperature and high pressure processing time. |