Enhancing the Mechanical Characteristics of Lightweight Concrete with Nano-Silica Additives

The use of Lightweight Concrete (LWC) in both structural and non-structural applications has gained significant attention due to its advantageous properties. The latter encompass diminished structural element overloading and reduced production and shipping expenses. However, the decreased density of LWC often results in compromised strength and durability. Nanotechnology has emerged as a promising approach in concrete technology, offering potential solutions to the challenges associated with reduced density in LWC. In this study, a concrete mix with a 1:3 ratio of cement to Lightweight Expanded Clay Aggregate (LECA) was used. The reference mix (LR) consisted entirely of LECA as aggregate. In the modified mix (LP), 10% of the coarse LECA aggregate was volumetrically replaced with recycled Unplasticized Polyvinyl Chloride (UPVC) plastic. To investigate the impact of Nano-Silica (NS), additional mixes were prepared by incorporating NS at dosages of 1%, 1.5%, and 2% by weight of cement into the (LP) mix, resulting in mixes LPN1, LPN2, and LPN3, respectively. This study investigates the effect of NS on the mechanical properties of the aforementioned concrete mixes, with a focus on the compressive and flexural strength.