Evaluation of the expanded glass as a light concrete aggregate

At present, the use of porous and lightweight materials has shown an increasing trend in different industrial areas. These materials are generally used to produce lightweight structural elements in the construction industry. Lightweight concrete has a much lower density than normal concrete. It is a material with many advantages, such as improved insulation performance due to its highly porous or cellular properties. Various types of lightweight aggregates are used to produce lightweight concrete and the properties of these lightweight aggregates significantly affect the material properties. In this study, expanded glass granules made from recycled glass were used in order to benefit from its light weight, non-flammability and low water permeability. In this study, the lightweight concretes were produced by changing the ratio of expanded glass and natural sand (Ratio of expanded glass: 0%, 5%, 10%, 15%, 20%). The same mortar mixtures were also prepared using a plasticizer additive to ensure workability and reduce water content. The compressive strength, modulus of elasticity, thermal conductivity, water absorption rates and unit weights of lightweight aggregate concretes produced in various unit weights were investigated. Density of concrete samples containing expanded glass is 1.5-2.2 g/cm3, water absorption rates are 4-16.69%, heat transmission coefficient is 1-0.0639 W/m.K, 28 day, compressive strengths vary between 18.3-68.8 MPa. Density, water absorption rate, heat conduction coefficient and compressive strength of concrete samples decreased as the ratio of expanded glass increased compared to control concrete samples. This reduction is due to the fact that the expanded glass has a low density (0.17-0.23 g/cm3), a low water absorption rate (23%), and a low heat conduction coefficient (0.0639 W/m.K). The 28-day compressive strength of expanded glass-containing concrete samples ranged from 18.3 to 68.8 MPa. As the proportion of expanded glass increased compared to the control concrete samples, the compressive strength of the concrete samples decreased. In this study, elasticity modulus of concrete was investigated by UPV testing method. Dynamic elasticity modulus decreased as the ratio of expanded glass increased compared to control concrete samples. The dynamic modulus of elasticity of concrete samples containing expanded glass in changes rouge of 18.6-40.23 GPa. The dynamic modulus of elasticity of concrete samples containing sand is higher. The use of expanded glass granules in light concrete production is thought to be very advantageous in terms of reducing the earthquake load of the structure, preserving the non-renewable natural resources, recovering the waste resources, preventing environmental pollution, protecting the energy and reusing the energy in production. The fact that the experimental results were compatible with the literature supported the usability of expanded glass granules in light concrete production. Key Words: Lightweight concrete, expanded glass, mechanical properties, elasticity modulus