Utilizing Lightweight Expanded Clay Aggregate as Coarse Aggregate in Concrete

In recent years, the need for sustainable building materials has encouraged the use of lightweight concrete (LWC), as it offers advantages such as reduced dead load, improved workability and enhanced environmental efficiency. In this work, the mechanical and structural performance of lightweight concrete (LWC) is examined by partially replacing coarse aggregate with Lightweight Expanded Clay Aggregate (LECA). The insulation and energy efficiency benefits of LECA are also discussed, as these properties result from the expansion of natural clay at elevated temperatures. An extensive experimental investigation was performed to study the compressive, tensile and flexural strength properties of LECA-based concrete with replacement levels of 0%, 5%, 10% and 15%. M25 grade concrete was used, maintaining a fixed water–cement ratio of 0.43 and the mix included PPC, fine aggregate, coarse aggregate and water. For better accuracy, the concrete specimens were cured for periods of 7, 14 and 28 days and workability was measured using the slump test. The findings indicate that replacing 5% of coarse aggregate with LECA improves the compressive strength, showing an rise of nearly 5.35% at 28 days. At 10% replacement, the compressive strength further rise by 12.14%, while at 15% replacement, it drop by approximately 9.97% compared to conventional concrete. On the other hand, tensile and flexural strengths rise up to 10% LECA replacement, with maximum rises of 14.29% and 10.26%, respectively, and then drop by 7.14% and 6.41% at 15% replacement. This shows that an optimum amount of LECA can enhance the properties of lightweight concrete without affecting its structural integrity.