Abstract
The aim of the work is to study the crack resistance of reinforced concrete beam fragments of three-layer floor slabs. Experimental studies of samples-fragments of reinforced concrete three-layer slabs with an average layer of expanded polystyrene material without internal ribs. Experimental data on crack resistance, formation and development of cracks in fragments and recommendations for calculation are given. Based on the results of experiments, the methodology of the calculation normative standard for the formation of inclined cracks has been refined and supplemented. The coefficient of safety which is included in the formula of the normative standard, taking into account the working conditions of the concrete of the lower layer of fragments of floor slabs, based on the experiments carried out, is recommended to be taken equal to 0.4-0.5