STRUCTURAL BEHAVIOUR OF STITCHING CONCRETE IN PRECAST CONSTRUCTIONS

Abstract

Stitching concrete is the practice ofjoining separate precast units together' in order to behave as an integral entity. Common connections in the prefabricated concrete have low moment capacity. This investigation has ": been conducted aiming at getting the highest integrity with these connections. The present study has been carried out xperimentally and numerically for three sorts of stitched elements: (I) Members subjected to axial loading, (2) Simply supported segmental beams and (3) Continuous segmental beams. Under compressive loading, five specimens were experimentally tested with different stitching angles (0, 30, 45° and 60°) in addition to one reference specimen with no stitching. Under tensile loading, finite element modeling was conducted with various lap splices, stitching lengths (100, 200, 300, 400, 50o and 60o) and different details (hairpin loop, hook and straight) and they were investigated. In addition, five segmental simply supported beams with the stitching zone at the mid-span with different reinforcement details (welded studs in tension, welded studs in compression, welded studs in tension and compression, welded lap splice, etc) were tested experimentally. Another specimen constituting three equal segments and a reference specimen were further considered.