This study investigates the influence of lightweight scoria aggregates and heavyweight hematite aggregates on the mechanical and radiation-related properties of self-compacting concrete (SCC), with comparison to normal SCC and conventional concrete.
Four concrete mixtures were prepared: normal self-compacting concrete (SCC), lightweight self-compacting concrete (SCC-L), heavyweight self-compacting concrete (SCC-H) and normal concrete (NC). After 28 days of curing, specimens were tested using uniaxial compressive strength, Brazilian tensile strength, Schmidt hammer rebound, ultrasonic pulse velocity, and gamma-ray attenuation coefficient measurements. Regression models were developed to establish empirical relationships between mechanical and non-destructive parameters, and their validity was assessed using statistical indices.
Normal SCC exhibited the highest compressive strength, approximately 15% greater than NC, while SCC-H showed an 8% increase. In contrast, SCC-L displayed an 18% reduction in compressive strength. Tensile strength was highest for SCC-H, exceeding NC by about 5%, whereas SCC and NC showed comparable values. Schmidt hammer rebound numbers were approximately 10% higher in SCC and 9% higher in SCC-L than in SCC-H and NC. Ultrasonic pulse velocities followed trends consistent with compressive strength. Gamma-ray testing demonstrated that SCC-H had a 15% higher linear attenuation coefficient than NC, while SCC-L showed a 12% lower coefficient.
This study provides a unified experimental framework combining mechanical testing, non-destructive evaluation and gamma-ray attenuation analysis for both lightweight and heavyweight SCC. The proposed empirical relationships offer practical tools for estimating concrete performance within the tested range and support the application of SCC in lightweight structural and radiation-shielding applications.
