High performance industrialised buiding system multi-layers slim beams

Abstract

The qualities and the quantities of materials are not controlled in proper way when a lot of concrete and many steel reinforcements are being wasted. Variation of the sizes of beams and columns are not simplified and generalized, which leads to the increase of cost of construction and unnecessary need. Nowadays, Industrialised Building system (IBS) has become an alternative to speed up the construction completion and to increase the flexibility. The IBS multi-layers slim beam with new type of connection is a new innovation. It is based on the concept of mobility and deployable to speed up the construction process, unification and adaptability. For this purpose, an experimental investigation into the behaviour of six IBS multi-layers slim beams made of high strength concrete and rectangular spiral shear reinforcement with new type of connection has been carried out in three different testing assemblies. These tests were carried out to determine the laboratory ultimate strength capacity of these multi-layers IBS slim beams and to assess the performance and the behaviour of connections. All specimens were connected to a column frame steel-section channel supported on a 3.4 m span. The models were subjected to two point loads. Deflections at various points, crack patterns, crack widths, strain in steel, strains on concrete surface and rotation of connection were recorded during the test. The concrete properties i.e. compressive strength and tensile strength were also recorded. It was found that the capacity of SET 2 (2 slim beams) increased by 87% with comparison to SET 1 (1 slim beam) and the capacity of SET 3 (3 slim beams) increased by 28% with comparison to SET 2 (2 slim beams). The crack patterns of all specimens were similar and the mode of ultimate failure was flexural behaviour. It was associated with crushing and spalling of the concrete at supports. The initial stiffness of connection increased with the increase of the number of slim beams in the set beam. The rotational capacity (ductility) behaved differently as the size of the combined beams increases, and the connections lose their ductility with the increasing number of slim beams. The experimental results were comparable with simulation results carried out by finite element software.