FRP Solutions for URM
Principal Researcher: Associate
Professor Jason Ingham
Students involved: Hamid
Mahmood, Dmytro Dizhur
Unreinforced masonry (URM) structures are considered earthquake-prone due to their often-observed poor performance in earthquakes. A significant number of URM buildings exist in New Zealand. The presence of these URM structures exposes the citizens of New Zealand to substantial risks in the event of an earthquake. According to an estimate, a major earthquake in national capital, Wellington, could leave up to 1,600 dead and 10,000 injured. The New Zealand Building Act 2004 requires all earthquake-prone structures to be either retrofitted to enhance their expected seismic performance or demolished.
In response to issues discussed above, a research programme has been initiated to develop economical and simple retrofit solutions for New Zealand’s URM buildings using fibre reinforced polymer (FRP) materials. FRP materials present advantages over conventional retrofit materials due to their ease of application and lower weights. Past studies have indicated the effectiveness of FRP materials as a seismic retrofit solution for URM structures. However, most of these studies have focussed on the testing of building components (walls). Additionally, there is a dearth of data on dynamic testing of URM components and buildings. Also, no FRP-URM bond strength data is available for New Zealand’s URM.
A comprehensive research programme has been designed that includes laboratory tests on both URM walls (components) and simple buildings. All test specimens will be built using recycled New Zealand bricks and retrofitted using different FRP materials. Both pseudo-static and dynamic tests will be performed. The test results will be used to create a database for use by related professionals and develop design guidelines for the seismic retrofit of URM structures using FRP materials.
Further information can be found in Mahmood, Russell and Ingham (2008) (reproduced with permission).
In-field seismic retrofit of URM buildings using FRP
A further study on In-field seismic retrofit of URM buildings using FRP is outlined below:
Past laboratory-based studies have shown the feasibility of fibre reinforced polymer (FRP) materials as a seismic retrofit solution for URM buildings. As a result, supplementary laboratory tests are currently being conducted on URM building components retrofitted using different FRP materials. Most of the research work on seismic FRP retrofit has been conducted using laboratory based-studies, where, actual field conditions are difficult to reproduce.
This study is specifically tasked to perform field testing of retrofitted masonry buildings using FRP strengthening for earthquake protection. This will provide data with which to validate the accuracy of models and laboratory-based studies of retrofit solutions. Testing will be conducted on existing masonry structures, mainly multi-storey and non-residential, that are scheduled for demolition. Masonry walls reinforced with FRP will be excited to induce plastic deformations, allowing the performance of retrofitting solution to be analysed.
The research aims to look into the following key aspects:
• Interconnection of research programs that are specifically focused on in-plane and out-of-plane loading
• International collaboration with The University of Adelaide and The University of Newcastle.
• Development of proof-tested seismic retrofit solutions using FRP materials, in conjunction with consultants, installers and material suppliers.
• Development of an FRP retrofit design protocol.