CRACK STRENGTH OF HOLLOW CORE SLABS: EXPERIMENTAL RESEARCH

Abstract

Introduction. The paper presents the results of research that allow assessing the degree of influence of pre-organized cracks on the character crack formation and on the process of the hollow-core slabs’ deformation under short-term load action.Materials and methods. The hollow-core slabs are made without prestressing – one by traditional technology, the second with pre-organized cracks in the manufacturing process. Physical experiment performed on fall-scale structure of hollow-core slabs of П66.10-81500СП. The authors conducted the tests to the calculated breaking load. Moreover, the authors presented the contrastive analysis of character crack formation and of the hollow-core slabs’ deformation of П66.10-8А500СП traditional manufacturing and with pre-organized cracks.Results. As a result, the authors confirmed the earlier hypotheses about the greater rigidity of plates with pre-organized cracks in comparison with the plates where the cracks arose stochastically and under operational load. The installation of organized cracks did not reduce the bearing capacity, thus, reduced the deformability. Therefore, the width of the crack became smaller and the deflections became less.Discussion and conclusions. In the structures of long length, which are rejected by the second limit group, the organization of cracks at the manufacturing stage allows not putting additional reinforcement to reduce the width and deflection of the crack.