Seismic assessment and retrofit development of precast prestressed hollow-core floors (2020)
Type of ContentPosters
- QuakeCoRE: Posters 
Precast floors are the dominant flooring system in New Zealand’s multi-storey buildings stock, where hollow-core floors are the most ubiquitous flooring system. Following the 2016 Kaikōura Earthquake, significant damage was observed in multiple buildings that incorporated hollow-core floors. Hollow-core flooring systems vulnerability in regions of high seismicity were exposed, and concerns were raised about the performance of these floors in future seismic events. Due to the prevalence of hollow-core floors it was clear that there is an urgent need for retrofit solutions and guidance, especially for areas with high seismicity such as Wellington. As a response to those needs the ‘ReCast Floors’ research group was formed with the objectives of improving the current understanding of the seismic performance of precast floors and develop suitable retrofit techniques. In the poster, results of the experimental investigations undertaken by the ‘ReCast Floors’ project so far are presented. Where multiple sub-assembly (single unit) tests with different retrofits have been tested and results analysed. Furthermore, initial results from recently completed super assembly (full scale single storey) test and plans for upcoming super assembly test will be presented. In addition to the laboratory testing, field investigation was undertaken. Extensive damage documentation of a case study building was performed to capture the severity and distribution of the damage sustained utilizing laser scanning and structure from motion techniques. This field investigation is expected to provide a means of determining the extent to which laboratory testing is representative of ‘real’ floors performance. Moreover, another flooring system, namely double tee floors is currently under investigation, and the proposed experimental testing will also be presented herein. This project is supported by Branz, Quakecore and Concrete Society.
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Seismic Damage Observations of Precast Hollow-Core Floors From Two Full-Scale Super-Assembly Tests. Büker F; Parr M; Hogan L; Bull D; Elwood K; Liu A; Sullivan T; De Francesco, Giovanni (2022)Serious concerns about the life safety risk of hollow-core floors during earthquakes were raised following the collapse of hollow-core units during the 1994 Northridge earthquake and in subsequent laboratory tests. To ...
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