Experimental studies of strength, rigidity and cracking resistance of lightweight slabs with combined reinforcement

Combined reinforcement of concrete structures means partial replacement of steel reinforcement with composite one. Such replacement is carried out in frame and slabby bending structures. Combined structures are structures consisting of various materials and involving various process operations, including the use of prefabricated and monolithic units, as well as prestressing. Since composite reinforcement has a number of specific features, the need arises to conduct experimental and theoretical studies. This article is devoted to the results of testing slabs of combined structure bent in two directions for transverse load. The structure of the slabs consists of lightweight blocks (wood concrete), monolithic heavyweight concrete and combined reinforcement (metal and composite reinforcement). A system of heavyweight concrete cross beams is formed, between which lightweight concrete is located. This removes the dead weight (mass) of the structure, which results in increased economic efficiency. Seven samples of lightweight rectangular slabs with dimensions of 2260 × 1660 × 100 mm have been manufactured to achieve the set objectives. Lightweight slabs are made with double reinforcement. As a result of experimental studies, the nature of the destruction of lightweight floor slabs and coatings with combined reinforcement, the deformation of elongation and shortening in the span sections under loading, the width of the crack opening and the nature of the formation of cracks have been established.