Mechanical properties and life cycle assessment (LCA) of waste glass reinforced concrete

As global warming continues and construction drains large quantities of natural resources, waste glass, a kind of solid waste that is difficult to degrade naturally, is gradually being used to alleviate the pressure of natural resource shortage. Waste glass powder (WGP) and glass fiber (GF) have been widely used in concrete production. This study aims to use WGP to replace traditional fine aggregates (FAs) and explore the effects of WGP and 1 % GF added alone and mixed at different replacement amounts on the mechanical properties (compressive strength, splitting tensile strength, and flexural strength) of concrete at different ages (7d and 28d) and observe the failure morphology. Water absorption tests are conducted to study their pore structures. While studying their mechanical properties and pore structures, considering the recycling of solid waste, the life cycle assessment (LCA) method is used to explore whether the replacement of WGP can achieve green environmental protection goals. The environmental impact of different types of concrete is evaluated to ensure that the mechanical properties of concrete will be further improved under the premise of green and low carbon. The results show that the mixed use of WGP and GF reduces the compressive strength of concrete, but the splitting tensile strength and flexural strength are improved. At 28 days, compared with ordinary concrete (F0G0), the splitting tensile strength and flexural strength of concrete with only added GF (F1G0) increased by 10.7% and 13.5%, respectively. When GF was mixed with 10 % WGP (F1G10), the flexural strength and splitting tensile strength increased by 21.5 % and 24.6 %, respectively. The main body of the concrete containing GF is intact (F1G0, F1G10, F1G20, F1G30), the crack width is thinner than that of F0G0, and the sound is deeper when it is destroyed. The water absorption rate of glass fiber-waste glass power concrete (F1G20) with a replacement amount of 20 % was the lowest, which was 6.1 % lower than that of F0G0. The LCA results show that concrete has an excellent influence on the environment when preparing concrete. Using alternative materials such as WGP to reduce the amount of FAs can reduce carbon emissions. The carbon emissions of FAs in F1G30 are 30% lower than that of F0G0.