Study On Activation Of Waste Glass Powder By Chemical Excitation And Hydrothermal Excitation

Waste glass recycled is one of the most important ways as theadmixture of concrete used in the construction engineering. It is critival thateffectively improve the activity to make glass powder as admixture used inthe construction project. Physical methods, chemical metheods andhydrothermal methods are general ways to activate activity of fly ash andother admixtures. Physical methods combined with chemical orhydrothermal methods can draw an ideal activation effect. In this paper,waste glass were milled35min to powder（WGP） activating activity byincreasing specific surface area. On this basis, chemical and hydrothermalmethods were introduced to stimulate activity of WGP.In chemical activation experiment, mortar were formed with cementand running water replaced by WPG and activator solution respectivelyreferring to Cement Mortar Strength Test Method (GB/T17671-1999).Compare to that of control sample, Copmpressive strength at different ageswere tested to evaluate the activation effect by raise rates. In the other hand,solid-liquid extraction method were introduced to test alkalinity ofWGP-cement paste sharing same mix proportion with mortar. Variation ofpore solution alkalinity is expected to evaluate the effect of activator oncompressive strength. Conclusions of reference value were drew, Na2SO4has outstanding activation effect on WGP at early ages and less at late ages.NaOH obtains some effect but irregular. Pore solution alkalinity has asignificant impact on the strength of sample, strength raise as pH goes up at7d and90d.The effect of hydrothermal activation indifferent temperature andpressure conditions on the pozzolanic activity of waste glass powder wasdiscussed. The waste glass powder was treated at108℃,0.15MPa,116℃,0.18MPa and121℃,0.2MPa for2h in an autoclave. Hydrothermal methodin this paper were improved on the basis of existing research and come conclusions of reference value are drew, hydrothermal activation hasremarkable effect in late stage and certain effect in early stage. Treating at121℃,0.2MPa, for2h, GPD-cement system with20%GPD got equivalentstrength with cement mortar at90d. Effect of hydrothermal activationimproves as temperature and pressure raise. Mechanism of hydrothermalactivation includes water erosion and alkali erosion.