Evaluation of Elastomeric Polymers for Retrofit of Unreinforced Masonry Walls Subjected to Blast
Author: James D. Connell
Publisher:
Published: 2002
Total Pages: 374
ISBN-13:
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Author: James D. Connell
Publisher:
Published: 2002
Total Pages: 374
ISBN-13:
DOWNLOAD EBOOKAuthor: Danica Leigh Thornburg
Publisher:
Published: 2004
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKTerrorist attacks have become increasingly common and severe. The weapon of choice Is the easily and cheaply made bomb. Most injuries and deaths occurring in bomb attacks are caused by flying debris due to the fragmentation of walls and windows. Many buildings in use today are comprised of unreinforced masonry walls that cannot withstand the load produced by even small explosive devices. Therefore, a critical need has arisen to strengthen walls In a timely and cost-efficient manner.
Author: Mahmoud M. Reda Taha
Publisher: Springer
Published: 2018-04-06
Total Pages: 699
ISBN-13: 3319781758
DOWNLOAD EBOOKThis volume collects the proceedings from the International Congress of Polymers in Concrete 2018 (ICPIC), held under the theme “Polymers for Resilient and Sustainable Concrete Infrastructure.” ICPIC 2018 provides an opportunity for researchers and specialists working in the fields of polymers to exchange ideas and follow the latest progress in the use of polymers in concrete infrastructure. It also showcases the use of polymers and polymer concrete in sustainable and resilient development, and provides a platform for local and overseas suppliers, developers, manufacturers and contractors using polymers, polymer concrete and polymer composites in concrete structures to develop new business opportunities and follow the latest developments in the field. The International Congress of Polymers in Concrete is an international forum that has taken place every three years for the last 40 years with the objective of following progress in the field of polymers and their use in concrete and construction. Following 15 successful congresses held in London (1975), Austin (1978), Koriyama (1981), Darmstadt (1984), Brighton (1987), Shanghai (1990), Moscow (1992), Oostende (1995), Bologna (1998), Honolulu (2001), Berlin (2004), Chuncheon (2007), Funchal (2010), Shanghai (2013) and Singapore (2015), the 16th ICPIC will take place in Washington, DC, from April 29 to May 1st, 2018.
Author: Yeping Wang
Publisher: CRC Press
Published: 2018-11-22
Total Pages: 872
ISBN-13: 1315640562
DOWNLOAD EBOOKThe International Conference on Energy, Environment and Materials Science (EEMS2015) was held in Guangzhou, China, from August 25 - 26, 2015. EEMS2015 provided a platform for academic scientists, researchers and scholars to exchange and share their experiences and research results within the fields of energy science, energy technology, environmental science, environmental engineering, motivation, automation and electrical engineering, material science and engineering, the discovery or development of energy, and environment and materials science.
Author: Hyunchul Jung
Publisher:
Published: 2020
Total Pages:
ISBN-13:
DOWNLOAD EBOOKUnreinforced masonry (URM) walls are commonly found in existing and heritage buildings in Canada, either as infill or load-bearing walls. Such walls are vulnerable to sudden and brittle failure under blast loads due to their insufficient out-of-plane strength. The failure of such walls under blast pressures can also result in fragmentation and wall debris which can injure building occupants. Over the years, researchers have conducted experimental tests to evaluate the structural behaviour of unreinforced masonry walls under out-of-plane loading. Various strengthening methods have been proposed, including the use of concrete overlays, polyurea coatings and advanced fiber-reinforced polymer (FRP) composites. Fabric-reinforced cementitious matrix (FRCM) is an emerging material which can also be used to strengthen and remove the deficiencies in unreinforced masonry walls. This composite material consists of a sequence of one or multiple layers of cement-based mortar reinforced with an open mesh of dry fibers (fabric). This thesis presents an experimental and analytical study which investigates the effectiveness of using FRCM composites to improve the out-of-plane resistance of URM walls when subjected to blast loading. As part of the experimental program, two large-scale URM masonry walls were constructed and strengthened with the 3-plies of unidirectional carbon FRCM retrofit. The specimens included one infill concrete masonry (CMU) wall, and one load-bearing stone wall. The University of Ottawa Shock Tube was used to test the walls under gradually increasing blast pressures until failure, and the results were compared to those of control (un-retrofitted) walls tested in previous research. Overall, the FRCM strengthening method was found to be a promising retrofit technique to increase the blast resistance of unreinforced masonry walls. In particular, the retrofit was effective in increasing the out-of-plane strength, stiffness and ultimate blast capacity of the walls, while delaying brittle failure and reducing fragmentation. As part of the analytical research, Single Degree of Freedom (SDOF) analysis was performed to predict the blast behaviour of the stone load-bearing retrofit wall. This was done by computing wall flexural strength using Plane Section Analysis, and developing an idealized resistance curve for use in the SDOF analysis. Overall, the dynamic analysis results were found to be in reasonable agreement with the experimental maximum displacements.
Author: Jiyoung Lee
Publisher:
Published: 2001
Total Pages: 118
ISBN-13:
DOWNLOAD EBOOKFiber-reinforced polymers (FRP) have recently been used for retrofitting unreinforced masonry (URM) structures which are especially vulnerable to out-of-plane earthquake loads. FRPs have high strength-to-weight ratio, high stiffness-to-weight ratio, high resistance to corrosion, and ease of applicability. Experiments are conducted to test the strength and ductility of FRP-retrofitted brick walls subjected to out-of-plane loading. Based on the material properties and testing set up, nonlinear finite element models were developed to study the effects of different material parameters.
Author: Laura Ciornei
Publisher:
Published: 2012
Total Pages:
ISBN-13:
DOWNLOAD EBOOKUnreinforced masonry walls subjected to blast loading are vulnerable to collapse and fragmentation. The objective of this thesis is to conduct experimental and analytical research for developing a blast retrofit methodology that utilizes polyurea. A total of four unreinforced masonry walls were constructed and tested under various shock tube induced blast pressures at the University of Ottawa Shock Tube Testing Facility. Two of the retrofitted walls had surface-sprayed polyurea. The results indicate that the use of polyurea effectively controlled fragmentation while significantly increased the load capacity and stiffness of masonry walls. Polyurea proved to be an excellent retrofit material for dissipating blast induced energy by providing ductility to the system and changing the failure mode from brittle to ductile. Single degree of freedom (SDOF) dynamic analyses were conducted as part of the analytical investigation. The results show that the analytical model provides reasonably accurate predictions of the specimen response.
Author: Reid Robert Senescu
Publisher:
Published: 2004
Total Pages: 200
ISBN-13:
DOWNLOAD EBOOKAuthor: American Society of Civil Engineers
Publisher:
Published: 2005
Total Pages: 1176
ISBN-13:
DOWNLOAD EBOOKVols. 29-30 contain papers of the International Engineering Congress, Chicago, 1893; v. 54, pts. A-F, papers of the International Engineering Congress, St. Louis, 1904.
Author: Jeremy Keith Wallace
Publisher:
Published: 2004
Total Pages: 314
ISBN-13:
DOWNLOAD EBOOKDuring recent years, near surface mounted (NSM) fiber reinforced polymer (FRP) bars have displayed exceptional results when used to retrofit un-reinforced masonry walls for flexural out-of-plane strengthening. This process involves cutting a shallow groove into the masonry wall, which is less than the thickness of the face shell. FRP bars are then placed into the groove and embedded in an epoxy paste, which transfers stresses from the masonry wall to the reinforcing bar. Although this retrofitting technique is advantageous for most structural applications, the nature of the bar location introduces an inherent restriction. By locating the bar at a depth no greater than the thickness of the face shell, the flexural strength is only increased in one direction. This limitation introduced an opportunity to develop a novel approach to flexural out-of-plane strengthening of masonry walls for cyclic loading, which was the overall objective of this research project. The retrofitting technique is similar to that of NSM rods; but the FRP bars are placed at the centerline of the wall analogous to traditional steel rebars for two directional reinforcing. Test results confirmed that FRP bars can be used to drastically increase flexural capacity of masonry walls subjected to cyclic loading, while remaining practical and beneficial in terms of field construction. Standard working stress equations were also used to conservatively predict the structural responses of the masonry walls within 9 to 15.8 percent.