The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Mahachi J. - One of the best experts on this subject based on the ideXlab platform.
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Limiting structural damage on masonry structures due to foundation movement
2019Co-Authors: Mahachi J.Abstract:Abstract: Over three million low-income houses have been built in the Republic of South Africa over the last two decades, many of which have experienced structural distress due to foundation movement or poor quality construction. The South African low-income housing sector employs a large number of entry-level ma- terial suppliers and building contractors, and this results in substantial variability of construction materials, technology and workmanship standards. Underpinning the foundation as a remedial solution to low-income houses is very expensive compared to the actual cost of the product (i.e. the house). Alternatively, it may be cost effective to demolish and rebuild the structure. In this paper, cost effective alternative to underpinning is explored using a proprietary type of reinforcement which is grouted to concrete Blockwork. The reinforcement and grout act compositely with existing concrete Blockwork, both to repair the cracks and to form deep rein- forced masonry beams. This paper covers the initial test programme to investigate and assess the suitability of different reinforcement systems to improve the structural strength and performance of concrete Blockwork Wall- ing systems. A series of tests were conducted on Blockwork Wall sections above window and door openings. The material specimens used for the investigation were sampled from a number of construction sites where the quality of the materials varied from site-to-site. The results of the tests showed strength enhancement of the Blockwork and an improved ductility
H. Salehi - One of the best experts on this subject based on the ideXlab platform.
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Finite-Element-Based Monte Carlo Simulation for Sandwich Panel-Retrofitted Unreinforced Masonry Walls Subject to Air Blast
Arabian Journal for Science and Engineering, 2019Co-Authors: B. Zehtab, H. SalehiAbstract:In this paper, the behavior of three types of masonry Walls is assessed subject to blast load as an out-of-plane impulse origin, and they are strengthened by the sandwich panel. The values of displacement and von Mises stress caused by blast loads are calculated using finite-element simulation. The modeled masonry Walls are constructed using brick, grouted concrete masonry unit and ungrouted concrete masonry unit. Blast load is modeled by means of the CONWEP (conventional weapon) tool. A reliability analysis is conducted to evaluate outputs statistically and to calculate failure probabilities using Monte Carlo method. Plasticity properties of masonry and steel materials are simulated using concrete damage plasticity and Johnson–Cook (JK) models, respectively. Blast load is applied in three different levels of mild, moderate and severe. Results show that sandwich panel strengthening can efficiently reduce the stress and displacement values for all masonry Wall types. Probabilities of failure in strengthened masonry Walls are significantly decreased. Moreover, in non-strengthened cases, grouted Blockwork Wall has a lower stress and displacement comparing to the other masonry Walls.
B. Zehtab - One of the best experts on this subject based on the ideXlab platform.
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Finite-Element-Based Monte Carlo Simulation for Sandwich Panel-Retrofitted Unreinforced Masonry Walls Subject to Air Blast
Arabian Journal for Science and Engineering, 2019Co-Authors: B. Zehtab, H. SalehiAbstract:In this paper, the behavior of three types of masonry Walls is assessed subject to blast load as an out-of-plane impulse origin, and they are strengthened by the sandwich panel. The values of displacement and von Mises stress caused by blast loads are calculated using finite-element simulation. The modeled masonry Walls are constructed using brick, grouted concrete masonry unit and ungrouted concrete masonry unit. Blast load is modeled by means of the CONWEP (conventional weapon) tool. A reliability analysis is conducted to evaluate outputs statistically and to calculate failure probabilities using Monte Carlo method. Plasticity properties of masonry and steel materials are simulated using concrete damage plasticity and Johnson–Cook (JK) models, respectively. Blast load is applied in three different levels of mild, moderate and severe. Results show that sandwich panel strengthening can efficiently reduce the stress and displacement values for all masonry Wall types. Probabilities of failure in strengthened masonry Walls are significantly decreased. Moreover, in non-strengthened cases, grouted Blockwork Wall has a lower stress and displacement comparing to the other masonry Walls.
Carl Hopkins - One of the best experts on this subject based on the ideXlab platform.
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Measurement of Kij with free‐standing masonry Walls
Journal of the Acoustical Society of America, 1999Co-Authors: Carl HopkinsAbstract:Measurements have been carried out to determine Kij values for masonry Blockwork Wall elements in the laboratory. Structural coupling measurements in the laboratory required investigation of the energy flow on the test construction in conjunction with the laboratory as well as determination of the coupling/material parameters. Experimental work was carried out on full‐size masonry Wall elements that were free‐standing upon a concrete floor base. Measurement procedures used to determine Kij were based upon proposals made by CEN/TC126/WG6. The intended use of the measurements was to investigate structural coupling between masonry Walls for the generic T‐junction with two different junction connection details, interleaved blocks and butted and tied Blockwork. To compare the two different types of junction connection, an H‐block construction was used that consisted of a single separating Wall element with four flanking elements. When the modal overlap determined from measurements was less than unity, the gene...
Nigel Thomas - One of the best experts on this subject based on the ideXlab platform.
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Trelagossick farm buildings, Veryan, CornWall. Building Recording (OASIS ID: nigeltho1-383552)
2020Co-Authors: Nigel ThomasAbstract:Proposals to convert disused farm buildings at Trelagossick, Veryan, CornWall resulted in a Planning Condition requesting historic building recording in advance of development. The farm buildings form part of the curtilage of a Grade II listed farmhouse. The subject building range dates from the early 19th century. The earliest and largest building is a two-storey cow-house with threshing barn over. A stable with another loft was added at one end and later another wing, most likely an animal house, was added to the rear. On the other sides of the farmyard (not part of the group subject to development proposals) a single-storey animal house was added during the mid-19th century and a further small building and pen constructed before 1907. The buildings were considerably altered during the later 20th century (the main barn roof was replaced with a single pitch modern roof and part of the front of the former stable was taken down and rebuilt with a Blockwork Wall). The interior of both these buildings was changed with conversion to a milking parlour, with concrete flooring added and partly cement rendered Walls. Modern sheds and shelters have been added to the sides of the buildings; some of these replace earlier lean-tos depicted on OS plans from 1880 and 1907. The historic development of the buildings represent gradual additions as farming requirements changed and budgets allowed, rather than a single development of a complete farmstead and yard
