Structural and mechanical performance characteristics of construction plasters with different material compositions and advanced geopolymerization

Abstract

Thermal performance-enhancing and weather-protective plasters for building elements are highly favoured in the construction industry. However, whilst substantial research has focused on the thermal performance characterisation of plasters, their mechanical properties still need to be explored. This study addresses exactly this gap by preparing plasters by TS EN 998-1 standard, with varying water/cement ratios of 0.8, 0.9, and 1. The plasters are formulated utilizing severe materials, including sand, perlite, and fibres. In addition, some plaster mixes are produced through geopolymerization by combining fly ash and blast furnace slag with a sodium hydroxide solution. The prepared plaster mixes underwent several mechanical and physical tests to determine the optimal configuration. These tests include flexural and compressive strengths, capillary water absorption values, adhesion strength, spreading diameter, and material weight loss under freeze-thaw conditions. The results indicate that diminishing the water/cement ratio enhances the flexural and compressive strengths of the plasters. Conversely, increasing the water/cement ratio improves the adhesion strength. The inclusion of polypropylene fibres reduces the adhesion strength, while perlite-containing plasters exhibit lower freeze-thaw losses compared to other mixes. These findings offer practical insights for improving plaster formulations, addressing real-world challenges, including material availability, cost-effectiveness, and production scalability. The study underscores the potential of geopolymerization to advance sustainable construction practices whilst identifying limitations in implementation for broader industry adoption.