Experimental Investigation of Lightweight Structural Concrete Using Expanded Clay and Expanded Perlite with Microstructural Evaluation

Abstract

Lightweight structural concrete has been a new construction material that promises to be effective because its application helps in reducing structural dead load without compromising on satisfactory strength and durability. Use of lightweight aggregates not only enhances structural efficiency of buildings, but also leads to sustainable construction as it lowers the total weight of the concrete elements. This paper is an experimental study of the characteristics of lightweight structural concrete manufactured in terms of lightweight aggregates of expanded clay and expanded perlite. The ultimate aim is to assess the impact of these materials on the fresh, mechanical, durability and microstructural properties of concrete. Ordinary Portland Cement, natural fine aggregate, coarse aggregate, expanded clay, expanded perlite, water and superplasticizer were used in making concrete mixtures where needed. The experimental program consisted of fresh density, compressive strength, split tensile strength, flexural strength, and water absorption experiments. Further, the scanning electron microscopy (SEM) was used to look at the pore structure, interfacial zone transition and aggregate-paste bonding of the hardened concrete. The experimental findings showed that the addition of expanded clay and expanded perlite considerably lowered the fresh density without compromising on the compressive strength needed in structural lightweight concrete. The optimization of the concrete mixture showed good tensile and flexural performance, good water absorption and a tighter microstructure with better bonding traits as well. These results indicate that expanded clay and expanded perlite are useful lightweight aggregates to manufacture structurally efficient and durable concrete. The research offers valuable information on how sustainable lightweight structural concrete can be developed in order to be used in building and infrastructural undertakings today.