EXPERIMENTAL STUDIES OF MULTI-LAYER SLABS UNDER THE ACTION OF STATIC LOAD

In recent years multilayer structures have become increasingly popular in construction practice due to their cost-effectiveness. In today's economic climate, this factor plays a crucial role. A significant reserve for increasing the efficiency of such structures is the use of fixed formwork. One of the most popular manufacturers of fixed formwork made of wood chip cement slabs is VELOX. The company's products are widely used in low-rise construction. Wood-cement slabs are wood-cement-concrete compositions in ‘fixed formwork’. It is a synthesis of natural materials ‒ stone and wood ‒ in a modern form. The purpose of this paper is to study the performance of multilayer slabs made using VELOX fixed formwork elements with different options for its fastening. The load was static. The tests of the prototypes were carried out until the appearance and opening of normal cracks in the lower tensile zone of concrete or until the deflection exceeded the critical value. Based on the experimental and numerical data the values of destructive loads and deformations in the experimental structures were obtained. During the tests the destruction of the prototypes occurred according to the classical scheme of destruction of bending elements with the fragmentation of the concrete of the compressed zone and the formation of normal cracks. Based on the test results the values of relative deformations of the extreme compressed and tensile fibres of the slab and the deformation at the interface of materials (concrete and VELOX), deflection values in the central zone were determined. The corresponding graphs were constructed. The bearing capacity of the slabs made using VELOX fixed formwork elements with different options for fixing the aggregate-cement slab (prototypes P2, P3) exceeded the bearing capacity of reinforced concrete slabs (marking P1) by 10 and 50 %, respectively. The practical application of multilayer complex structures requires further experimental research in this area. This will make it possible to find optimal design solutions for structures using structures of this type.