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.
Effectiveness of a novel ductile detailing of reinforced concrete wall–flat slab joint
ABSTRACT An experimental investigation on the behaviour of two identical structural wall–flat slab subassemblies was conducted by testing scaled down joint models: one with conventional reinforcement detailing at the joint and the other with a proposed novel reinforcement detailing at the joint region under lateral seismic type loading. A theoretical analysis was carried out by establishing the cleavage pattern and the state of stress at the joint region. As per the results, it was observed that the proposed novel reinforcement detailing exhibited improved ductility in the joint region ensuring increased energy dissipation which is desired under seismic loading.
Evaluation of buckling load and dynamic performance of steel shear wall retrofitted with strips made of shape memory alloy
One of the most imperfections of the steel shear wall is out of plane displacements that cause severe damage in both structural and non-structural elements. In this paper, the effects of shape-memory alloys on steel shear walls are investigated. First, a numerical analysis using the finite element method in ABAQUS software has been carried out according to an experimental test. The results of the numerical analysis have been verified with experimental results. Next, shape-memory alloy fibers have been added vertically and horizontally to various parts of the steel shear wall. The results show that retrofitting with the shape-memory alloy reduces the out-of-plane displacement of the steel shear wall under both cyclic and seismic loadings. Besides, the buckling load in the steel shear wall increases when it is retrofitted with the shape-memory alloy. Also, the total out-of-plane movement (accumulated absolute displacements) of the steel shear wall and non-structural damage are controlled by the characteristic of a shape-memory alloy material called “super-elastic”.