1 Background
1.1 Waste Glass
1.2 Recycled Glass in Mortars and Concretes
1.3 Research Significance
2 Experimental Investigation
2.1 Materials
2.1.1 Cement
SiO2 | Al2O3 | Fe2O3 | CaO | MgO | Na2O | K2O | SO3 | Loss on ignition | |
---|---|---|---|---|---|---|---|---|---|
% | 21.4 | 5.3 | 0.2 | 67.5 | 1.2 | 0.05 | 0.08 | 2.6 | 1.6 |
2.1.2 Aggregates
SiO2 | Al2O3 | Fe2O3 | CaO | MgO | Na2O | K2O | SO3 | |
---|---|---|---|---|---|---|---|---|
% | 73.3 | 1.5 | 0.06 | 9.8 | 0.35 | 14.2 | 0.6 | 0.2 |
2.1.3 Admixtures
2.2 Mix Proportions
Specimen | Water (kg/m3) | Cement (kg/m3) | Sand (kg/m3) | Gravel (kg/m3) | Glass (kg/m3) | Superplasticizer (kg/m3) | Silane (kg/m3) |
---|---|---|---|---|---|---|---|
0% | 286 | 609 | 548 | 822 | 0 | 0.5 | – |
33% | 286 | 609 | 548 | 551 | 256 | 0.4 | – |
66% | 286 | 609 | 548 | 280 | 512 | 0.3 | – |
100% | 286 | 609 | 548 | 0 | 776 | 0.2 | – |
0% + H | 282 | 609 | 548 | 822 | 0 | 0.5 | 6.77 |
33% + H | 282 | 609 | 548 | 551 | 256 | 0.4 | 6.77 |
66% + H | 282 | 609 | 548 | 280 | 512 | 0.3 | 6.77 |
100% + H | 282 | 609 | 548 | 0 | 776 | 0.2 | 6.77 |
2.3 Sample Preparation
2.4 Testing Details
2.4.1 Fresh Properties
2.4.2 Mechanical Properties
2.4.3 Drying Shrinkage
2.4.4 Water Vapour Permeability
2.4.5 Capillary Water Absorption
2.4.6 Expansion Due to Alkali–Silica Reaction
3 Results and Discussion
3.1 Workability
Specimen | Workability (cm) | Hardened density (kg/m3) |
---|---|---|
0% | 20.0 | 2130 |
33% | 18.8 | 2120 |
66% | 19.5 | 2110 |
100% | 18.5 | 2100 |
0% + H | 18.3 | 2130 |
33% + H | 18.7 | 2120 |
66% + H | 18.5 | 2110 |
100% + H | 18.5 | 2100 |
3.2 Mechanical Properties
3.3 Drying Shrinkage
3.4 Water Vapour Permeability
3.5 Capillary Water Absorption and Expansion Due to Alkali–Silica Reaction
4 Conclusions
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Improved workability, with consequent reduction of the dosage of superplasticizer and less costs, to obtain a certain workability value;
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Only a small penalty (16% max) in the compressive and flexural strength which does not prevent the use of waste glass mortars also for structural uses (Rc ≥ 25 MPa according to EN 1504-3:2005);
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An increase in the dynamic modulus of elasticity up to 12% at 100% replacement thanks to the greater stiffness of glass compared to the calcareous gravel;
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No decrease in the durability properties in terms of capillary water absorption;
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No decrease in water vapour permeability;
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Enhanced durability due to decreasing in drying shrinkage related to an increase of the modulus of elasticity.