Physical characteristics and mechanical properties of a sustainable lightweight geopolymer based self-compacting concrete with expanded clay aggregates

Geopolymer Concrete (GPC) is a unique and sustainable building material that has the potential to be trans-formed into a self-compacted lightweight composite for industrial applications. This paper investigates the sustainability of self-compactable lightweight geopolymer concrete (SCLGC) made from Expanded Clay Aggre-gate (ECA) to further explore this front. In this study, the physical properties of SCLGC, such as slump flow test, T500 test, V-funnel, and J-ring tests, are examined. Furthermore, the density, Ultrasonic Pulse Velocity (UPV), compressive strength, splitting tensile strength, and impact resistance are also tested to evaluate the mechanical properties of SCLGC mix with various concentrations of Sodium Hydroxide (SH) cured under different curing regimes. The aforenoted properties are examined following the American, Indian and European guidelines. In addition, microstructural analysis is conducted to assess the compactness and internal structure of SCLGC blends with varying SH concentrations cured under different curing regimes. Finally, the sustainability aspects of GPC and SCLGC mixes are analyzed through the Life Cycle Assessment (LCA) and Environmental Impact Assessment (EIA) to evaluate the energy requirement and CO2 emission and cost. The Sustainability analysis was performed to evaluate the energy requirement and CO2 emission of SCLGC in the production of 1 m3 concrete based on the previous literatures. The significance of the proposed research work emphasizes the utilization of ECA as an aggregate material for the development of SCLGC. The cost, carbon and energy efficiency of the SCLGC's mixes were estimated. Mix with ECA requires higher energy demand and emits high CO2 in the open atmosphere. Based on the present analysis it can be concluded that an increase in the concentration of activator solution increases the energy demand and emits more amount of CO2. The inference from the present study reveals ECA can be employed for the production of SCLGC with the replacement percentage not exceeding 50%.