Study On The Influence Of Glass Powder Used As Mineral Admixture On The Performances Of Precast Concrete Wall Panel Adhesive

With glass is widely used in daily life and industrial production, the amount of waste glass continue to increase, while the recycling rate is low. Most of the waste glass is directly buried that cause damage to the environment and land. Hence an efficient reusing way for waste glass is needed. Many studies show that if the waste glass is grounded into powder and widely used as mineral admixtures in cement concrete or mortar in the consruction, which will not cause the alkali-aggregate reaction and it is an ideal way of reusing waste glass. But the application research is rarely about the activity of glass powder. And, the experiment results are different due to differences in experimental conditions, raw materials.In order to solve the above problems, firstly, this paper studied the activity of the different particle size glass powder, and proposed to use glass powder to prepare precast concrete wallboard adhesive. And then the adhesive mix proportion without glass powder is studied. And on the basis of the mix proportion study, the influences of glass powder on the performance of the adhesive are studied. The main research contents and conclusions are as followings:(1) An orthogonal experiment was carried out to study the influence of glass powder on the strength, the ratio of compressive strength to flexural strength and mobility of cement mortar. And calcium hydroxide absorption and the evaporation of water content of different particle size glass powder are studied through a calcium absorption method. Results show that glass powder has reactivity and the more fine is the glass powder, the better is the reactivity; Glass powder with particle size less than 30 μm has better activity relatively and similar to the reactivity of fly ash; Glass powder dosage has a significantly influence on mortar strength.W ith the increase of dosage of glass powder, mortar strength reduced, but ratio of compressive strength to flexural strength is significantly lower too. Hence glass powder is more suitable for the preparation of adhesive for precast concrete wall panel with low strength but good toughness.(2)An orthogonal experiment was carried out to determine the dosage of HPMC, VAE, the range of cement-sand ratio preliminary. And then, a single variable experiment was carried out to further study the influences of cement-sand ratio and VAE dosage on the properties of adhesive. And ultimately determine the optimal proportion: Aggregate is a mixture of 0.15~0.30 mm sand and 0.30~0.60 mm sand with mass ratio 0.80, 587 kg/t; HPMC dosage is 0.9kg/t; VAE dosage is 50 g/kg; Cement-sand ratio is 0.7, cement 362 kg/t.(3) On the basis of the optimal proportion of adhesive, the flat glass powder, glass bottle powder, and other mineral admixture such as fly ash are used in adhesive, its effect on the adhesive properties are studied. Experiment results show that influences of flat glass powder and glass bottle powder on the performance of the adhesive are similary. And with the increase of the doseage of mineral admixture, harmful pore ratio increases to reduce the adhesive strength, but other performances are not declined significantly, which can satisfy the technical requirements. The glass powder can be used in adhesive extensively that the optimal dosage is 30%. If lime stone powder or talcum powder is extensively used in adhesive, the water resistant cohesive strength is lower compared with glass powder at the same doseage. When the dosage of lime powder or talcum powder is more than 30%, the crack resistance of adhesive is poorer, and when the dosage of fly ash or talcum powder is 20%, the adhesive has greater lateral deformation, the dosage of fly ash, lime stone powder, talcum powder should be controlled within 20 %.(4) At last, the costs of the adhesive with glass powder and other mineral admixture are compared. The result show that the adhesive with glass powder has a lower cost compared with the control adhesive and similar to adhesives with other mineral admixtures; Glass powder was used to prepare adhesive is not only technically feasible, but also economically feasible.