An investigation on effect of rebar on structural behaviour for wall-slab system
The government is taking the leading role to persuade the construction industry to engage a more systematic approach and methodology in construction by adapting the Industrialized Building Systems [IBS]. Wall-slab structural system is an IBS system which is suitable for use in residential building. Moment transfer of joint is an important aspect for proper structurally functioning of wall-slab system. Hence, the main aim of this study is to investigate the effect of reinforcement details in the wall on bending capacity for support stiffness in wall-slab system for residential project in Malaysia. A total of six wall specimens were tested. Three of this specimens consisted single layer of rebar while another three specimen consisted of double layer of rebar. The size of the wall-slab's specimens is 1000 mm in length [L], 1080 mm in width [W], 1000 mm in height [H] and 80 mm in thickness [T]. The average concrete strength Grade 30 N/mm2 and the average yield strength of R5 bar was 817 MPa. The bending capacity at failure for single layered of rebar in wall for specimen 1, 2 and 3 were found to be 3.59 kNm, 3.81 kNm and 3.15 kNm, respectively. The bending capacity at failure for double layered of rebar in wall for specimen 1, 2 and 3 were 5.50 kNm, 6.31 kNm and 7.00 kNm, respectively. The difference in stiffness of double layered reinforced concrete wall based on load-deflection curve 116.2 % to 289.9 % higher than single layered reinforced concrete wall. While based on the experimental results, specimens with double layered rebar in wall is found with higher bending capacity by 56.3 % to 98.9 % compared to single layered of rebar in wall. Experimental data on bending capacity provides important input in the process of structure analysis. Others than that, the outcome obtained from the study can serve as an useful guideline in the design of an efficient joint in wall-slab structural system.
Seismic performance on stiffness and hysteresis loop of interior wall-slab joint for tunnel form building designs to British standard
Wall-slab is a system suitable for use in the field of high-rise building where the main load resisting system is in the form rigidly connected wall-slab member. This paper presents the performance of a full-scale wall-slab joint in tunnel form system subjected to lateral cyclic loading. The objectives are to determine seismic behavior on the hysteresis loops and stiffness. Interior wall-slab joint was tested up to failure drift of 1.5%. The biggest hysteresis loops were occurred at the closest to the double actuator. The stiffness of wall-slab joint started to decrease from 0.25% drift until 0.5% drift and lost it stiffness after 0.5% drift. Incretion of the percentage of reinforcement bars in the wall-slab and proper detailing at joint is required for seismic loading. Keywords: wall-slab; hysteresis; stiffness; joint; cyclic
Mixed options for precast concrete construction
This article examines the rationale behing mixed construction, citing many examples from across Europe. It focuses on the leading role of precast concrete, particularly prestressed concrete floors, which can be used in nearly all types of buildings. Mixed construction maximises the structural and architectural advantages derived from combining components made of different materials, but it requires the cooperation of the architect, structural engineer, manufacturer, supplier and the contractor.