The effects of filler glasses on mechanical properties of concrete

Abstract

According to the relevant literature, the utilisation of different kind of glasses in concrete introduces positive effect on the mechanical behaviour. The factor affecting physical and mechanical properties and chemical endurance of concrete is the amount of structural pores, which form within its structure. Suitable filler materials can be used in concrete to decrease them. Such a material possesses not only pore filling ability but also pozzolanic character. Therefore, employing glasses as an additive in concrete can improve the final mechanical properties. In the present study a filler glass with a chemical composition of 40 SiO2, 14 ZrO2, 15 SrO, 20 MgO and 11 Fe2O3 (in wt.%), was used as an additive in the preparation of concrete. Filler glass additive percentages by weight relative to cement were 0, 5, 10 and 15. The water: cement ratio was 0.45 and the type of cement employed was Portland 42.5. After the concrete specimens were cured for 7, 28 and 56 days the compressive strength, indirect tensile strength, 28 and 56 days water absorption and capillary permeability parameters were measured. Dynamic modulus of elasticity was also determined for the 28 days-cured specimens by ultrasound test. The results showed that the concrete specimens with 15% glass gave better results than 10% glass substitution in terms of compressive strength, indirect tensile strength, water absorption and capillary permeability. Consequently, it was observed that the relative properties were improved by adding the filler glass as 10 and 15% unlike 5% incorporation.