Masonry Confinement Using Steel Strips
This paper presents the behavior of masonry columns confined with steel strips for increasing the axial capacity and stress-strain relationship. The test specimens are divided into three groups; each consists of three specimens with the variables: amount of reinforcement and cross-section aspect ratio. The cross-sectional aspect ratio of the three groups were 1, 2, 3 respectively. The experimental data and highlights different aspects of confinement. The steel strips enhance the ultimate stress and strain but this increase in strength is dependant on the cross-sectional aspect ratio. It is also concluded that the increase in load-carrying capacity and the deformability of masonry is significantly enhanced due to confinement using steel strips and the increase is linear to the average confining stress. The confinement of masonry with steel strips is quite viable and cheap option for strengthening
Problems Related to the use of Fiber Reinforced Cementitious Materials as Strengthening of Masonry Members
This paper gives the results of a series of tests carried out on brick columns and panels reinforced with Fibre Reinforced Cementitious Materials. Steel and glass fibres were used, and cement and lime mortars were employed as the matrices. The issue of durability of reinforced masonry structures, that is the transformation from sole masonry structures to hybrid ones, was investigated. Six brickwork columns (three unreinforced and three reinforced) and eighteen solid brick panels were built and tested (two unreinforced, 16 reinforced with steel cords or glass fibre). Tests were carried out in laboratory, and the results enabled the determination of the compression strength of the masonry before and after the application of the reinforcement, and before and after environmental effects. The main goal of the durability testing was to verify whether the artificial ageing process hinders the resistance. At the end of the cycles, a first visual observation was performed in order to evaluate if superficial alterations took place, such as efflorescence or micro cracking due to the immersion in the sodium chloride (NaCl) solution. The aged reinforced specimens appear to have a losses that range from 4% to 25% of the ultimate load, depending on the type of reinforcement and mortar used, although scattering of results confirm the need of more extensive testing.
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”.