INVESTIGATE THE PROPERTIES OF CONCRETE WITH LIMESTONE POWDER AS A PARTIAL REPLACEMENT OF CEMENT AND WASTE GLASS AS PARTIAL REPLACEMENT OF FINE AGGREGATE.

Abstract

Concrete is the most widely used material in the world. The cost of building materials is rising in Ethiopia and around the world due to increased infrastructure and development in construction activity. A binding material, fine aggregate, coarse aggregate, and water are the usual components of concrete. Ordinary Portland cement (OPC), the most common type of cement used in concrete, acts as a bonding agent for the fine and coarse aggregate. But Portland cement is expensive and a major generator of CO2, which contributes to a host of environmental problems. When river sand is used as fine aggregate, natural resources are exploited, the water table drops, bridge piers sink, and the river bed erodes. Appropriately getting rid of the massive amount of glass waste has become a serious environmental problem in many countries. Laboratory experiments were conducted to further explore the use of waste glass as fine aggregates for ASR (Alkali Silica-Reaction) alleviation in concrete. The study examined the chemical composition and physical properties of LP and GW, the workability of fresh concrete, the mechanical properties and durability of concrete, and also the microstructural analysis of hardened concrete. The consistency and setting times) increase as the LP and GW replacement amounts increase, but workability decreases as replacement increases. The compressive strength results at 7, 14, and 28 days indicate that the optimal performance is achieved with a 5% replacement of limestone powder in cement and 30% glass waste in fine aggregate for producing C-25 concrete. Additionally, both flexural and split tensile strengths at 28 days demonstrate similar enhancements. The compressive strength with up to 10% limestone powder replacement and 30% glass waste surpasses the average target strength. However, when the limestone powder replacement exceeds 10%, there is a decline in compressive, flexural, and tensile strengths. Durability tests show that mix M4 exhibits better resistance to water absorption, sulfate attack and carbonation test. Furthermore, the microstructural analysis of mixes M1 and M4 post reaction was conducted using XRD and SEM techniques.