OPTIMIZATION OF LIGHTWEIGHT PRECAST-MONOLITHIC SLABS WITH POLYSTYRENE VOID FORMERS

This article is dedicated to the optimization of parameters of lightweight precast-monolitic slabs incorporating polystyrene void formers, which represent one of the promising structural solutions in modern construction. The use of polystyrene inserts allows for a significant reduction in the self-weight of the slab and a decrease in material consumption, making this technology especially relevant under current construction conditions. However, in order to achieve optimal technical and economic performance, it is necessary to properly select the design parameters, particularly the characteristics of the inserts, the type of reinforcement, and the geometric properties of the slab. The purpose of the study is to optimize these parameters to achieve the best possible combination of cost-effectiveness, structural strength, and deformation performance. As part of the research, several design alternatives incorporating polystyrene inserts of various thicknesses and reinforcement types were analyzed. Mathematical modeling methods were applied using the LIRA software package. Based on the performed calculations, it was determined that slab configurations with polystyrene inserts ranging from 150 mm to 180 mm in thickness demonstrate the most favorable balance between economic efficiency and structural performance. These options significantly reduce the consumption of materials (concrete and reinforcement) without compromising the strength and reliability of the floor system. One of the key findings is the identification of optimal reinforcement layouts for each of the analyzed slab configurations, which allows reducing of reinforcement costs while maintaining structural strength. The study also revealed that increasing the thickness of polystyrene inserts beyond a certain threshold leads to a rise in overall construction cost, which is not justified from an economic efficiency standpoint. Based on the obtained results, it can be concluded that lightweight precast-monolithic slabs with polystyrene inserts represent an efficient and economically advantageous solution for modern construction, provided that the structural parameters are properly selected.However, to achieve maximum effectiveness, it is necessary to take into account not only the mechanical properties but also the economic and technological factors that influence the design and construction processes. Future research should focus on investigating the durability of such structures under various operating conditions, as well as on optimizing the installation process to reduce labor costs and increase construction speed.