PSI - Issue 71

Sphurty Raman et al. / Procedia Structural Integrity 71 (2025) 409–416

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Fig. 2 Impact of Recycled Concrete Aggregate (RCA) Content on Concrete Properties

Fig. 3 Impact of 40% RCA with Varying WGP Content on Concrete Properties

3.1 Mechanical and Durability Properties with RCA Concrete As RCA content increases from 0% to 60%, as shown in Fig. 2, compressive, flexural, and split tensile strengths consistently decline, primarily due to the weaker adhered mortar in RCA, a weaker bond in the interfacial transition zone (ITZ), and higher water absorption (which rises from 5.28% to 11.24%). Compressive strength drops by 26.42%, split tensile by 26.56%, and flexural strength by 25.50% at 60% RCA, indicating a uniform impact on the concrete matrix. Workability decreases slightly, with slump reduc ing by 7.22% (from 97 mm to 90 mm), likely due to RCA’s rough texture and angular shape. Despite these effects, up to 40% RCA replacement maintains acceptable strength for many applications. Therefore, we will use 40% RCA in further analyses while introducing varying Waste Glass Powder (WGP) levels to explore their combined effects on concrete properties. 3.2 Mechanical and Durability Properties with Varying WGP Content in 40% RCA Concrete Incorporating waste glass powder (WGP) into concrete with 40% recycled concrete aggregate (RCA) results in declining strength and workability as WGP content increases from 0% to 40%, as depicted in Fig. 3. Compressive strength decreases by 10.10%, flexural strength by 13.53%, and split tensile strength by 7.87%. Water absorption rises by 18.50%, indicating increased porosity, while slump drops significantly by 35.48%, making the mix stiffer. The reduced workability is due to the angular glass particles, which increase friction, and the higher water absorption by WGP. Strength reductions are likely caused by a weaker bond between glass particles and cement paste. A WGP content of 25% offers a balance, with moderate strength reductions and manageable increases in water absorption and slump loss. This mix is a viable option for sustainable concrete, but additional measures like superplasticizers may be needed to ensure durability. Further research is recommended to validate its long-term performance.