Investigation of production and performance evaluation of high-strength lightweight concrete (HSLWC) produced with regional volcanic aggregates (RVA).

This study investigates the feasibility of producing high-strength lightweight concrete using regional volcanic aggregate (RVA) and examines the performance of the produced concrete. Various mix designs conforming to ASTM and TS EN standards were applied to achieve the targeted strength and density. The study also investigated the effect of water/cement ratio (W/C) and cement content on the mechanical and physical properties of high-strength lightweight concrete. Experimental tests such as compressive strength, tensile strength, density, water absorption, and elastic modulus were conducted to determine the effect of cement content and lightweight aggregate on the overall behavior of the concrete. To ensure adequate workability, superplasticizer was added to all mixes at a rate of 1.5% of the cement weight. The slump values ​​of fresh concrete met modern requirements for good workability, pumpability, and high strength. The results showed that, provided a superplasticizer is used, high-strength concrete with a density range of 1830 to 1915 kg/m³ can be produced using 450 kg/m³ of cement. The results show that the porous structure and pozzolanic properties of RVA significantly increase the mechanical strength of concrete and, thanks to its porous structure, reduce its unit weight by 20–25%. The highest compressive strength recorded within 90 days for a mixture containing 650 kg/m³ of cement was 87 MPa. It was concluded that the W/C ratio and cement content have a significant effect on the mechanical and physical properties of these concretes.