ANALYSIS OF STRENGTH AND STIFFNESS OF PERMANENT FORMWORK BLOCKS WITH A WIDTH OF 300 TO 400 MM FOR LOW-RISE CONSTRUCTION

The article investigates the structural performance of concrete blocks used as permanent formwork in low-rise construction, with widths ranging from 300 to 400 mm. These blocks serve as both formwork and part of the structural system, providing a durable solution for wall construction. In Ukraine, the adoption of such blocks is limited due to underdeveloped reinforcement methodologies, which complicates their application in construction projects. The authors examine the strength and stiffness of a standard block with dimensions of 500×400×200 mm, using software-based modeling in TechEditor to streamline the calculations. This research produces graphical data on load-bearing capacity and bending stiffness, which designers can use to configure reinforced concrete walls with these blocks. The study also offers practical reinforcement guidance, filling gaps in current standards and assisting engineers in implementing these blocks effectively. Permanent formwork blocks, common internationally, typically contain voids and channels that facilitate rebar installation, creating a monolithic structure after the concrete sets. However, due to inconsistencies in reinforcement advice from manufacturers, Ukrainian engineers often resort to custom approaches or traditional monolithic construction. This study, therefore, aims to address these challenges by providing structured reinforcement recommendations. The research includes load-bearing and stiffness calculations for walls with variable depth (300-400 mm), accounting for different rebar diameters to simulate the range of possible configurations. Findings demonstrate that using blocks with rebar yields significant material savings (approximately 33% less concrete) compared to solid walls, without proportionate strength loss, making them a cost-effective choice for low-rise construction. In conclusion, the article offers engineers and manufacturers valuable insights into the practical use of permanent formwork blocks, presenting a foundation for further research into optimization and broader applications. Keywords: reinforced concrete, block, formwork, reinforcement, analysis.