Influence of Expanded Clay Aggregate on the Engineering Properties of Lightweight Concrete

Abstract

In seismically active locations, civil infrastructures, such as buildings, bridges, and dams, are frequently subjected to earthquakes. Using lightweight construction materials is one method for enhancing the seismic resistance of infrastructure. This study examined the engineering properties of lightweight concrete manufactured using expanded clay aggregate, with the purpose of developing sustainable and environmentally friendly building materials. Laboratory tests focused on the effects of the aggregate shape and the supplementary superplasticizer, as well as on the influence of the concrete age. Experimental studies were conducted to measure fresh (slump) and hardened properties (compressive strength, splitting tensile strength, and density). The expanded clay aggregate was produced by burning at a temperature of 800 to 1 200 °C. Cubic, oval, and round aggregate shapes with a maximum size of 20 mm were evaluated. This study also examined the effect of superplasticizers on the engineering properties of lightweight concrete. The composition of the superplasticizer varied from 0 to 2,5%. According to the experimental results, the engineering properties of lightweight concrete made with oval aggregates are advantageous in comparison with those using cubic and round shapes. It is also demonstrated that optimal amounts of superplasticizer are necessary to develop materials with adequate properties. It can be concluded that expanded clay aggregate can be used as an alternative material to produce lightweight concrete.