Experimental assessment and retrofit of full-scale models of existing RC frames

PSD tests on two full-scale models of existing non-seismic resisting RC frame structures are described. The testing program covered several aspects, namely assessment of seismic performance of existing frames without and with infill panels, retrofitting of the bare frame using Selective Retrofitting techniques, strengthening of the infill panels using shotcrete and retrofitting of the frame using K-bracing with shear-link dissipators. The main results from the tests are summarized and discussed and the conclusions are drawn. The tests on the bare frame have shown how vulnerable are existing structures constructed in the 60’s and the beneficial effects of infill panels were confirmed from the tests on the infilled frame. Important improvements, in terms of seismic performance, were achieved by the retrofitting of the frames. However, it was also confirmed that strengthening of the existing infill panels in poorly detailed frames may lead to dangerous ‘local’ failures, such as the shear out of the external columns

A Short Guide to Setting Up a City Scale Retrofit Program

Buildings represent 38.9% of U.S. primary energy use and 38% of all CO2 emissions in the U.S. Though simple, relatively low-cost measures such as insulation, and lighting upgrades can be done in almost every building to reduce energy use and save money on utility bills, current retrofitting program capacity is limited. Most existing programs are either available only to income-eligible individuals or those with the money up-front to do the work. Furthermore, many current retrofitting programs only create low-wage, short-term jobs rather than providing pathways into sustainable careers in construction and green building. Clearly, a new model is needed. This guide by Green For All and the Center on Wisconsin Strategy provides a model for designing and implementing weatherization and retrofitting programs on a citywide scale, with a goal of making such retrofits available to all and realize their potential to address climate change, put people to work, and reduce our energy bills

Dynamic nonlinear analyses for the 4-storey infilled R/C frame: study of a retrofitting solution

A research project on assessment and retrofitting of R/C frame structures is currently being developed under the research programme of the ICONS TMR-research network. This paper presents and discusses the preliminary experimental results from a 4-storey bare frame representative of the common practice of 40~50 years ago in most south European countries and devotes special attention to the study of a retrofitting solution based on bracing and rubber dissipaters, which intends to increase stiffness and damping reducing consequently the earthquake deformation demands.O estudo aqui apresentado concentra-se numa solução de reforço de um pórtico utilizando contraventamentos (k-bracing) com perfis de aço em conjunto com elementos elastoméricos de dissipação. Os resultados das análises não lineares da estrutura com e sem alvenaria e com reforço são apresentados e discutidos. Na segunda parte da comunicação apresentam-se os resultados experimentais já disponíveis e discute-se o problema da modelação recorrendo aos resultados experimentais e comparando os resultados obtidos com diferentes tipos de modelos

Revitalization of Cracked Flexural Members using Retrofitting and Synthetic Wrapping

The modification of the Indonesia earthquake code SNI 2002 to SNI 2012 resulted in a significantly higher performance demand. The basics of these amendments lay in the re-zoning of earthquake maps, and the consideration of the earthquake influence to gravity loads. Members designed based on the SNI 2002 most likely will result in failure under future earthquakes. A reinforcement method based on the ACI 440 provision was conducted on cracked flexural members. The tensile reinforcement of these members has yielded and was neglected in the design. The tensile strains and stresses were further carried by the synthetic wraps applied to the tensile concrete fibers. The shear capacity of the member was enhanced by confinement of the member using the same synthetic wrap. Prior to wrap application, the members were straightened and retrofitted with an epoxy resin injection. The member was tested using a one-point-loading system to simulate a maximum bending moment in combination with maximum shear forces. The load-displacement responses and the ultimate load carrying capacity under monotonic incremental loading were recorded. It was found that this method will provide a solution for revitalization of cracked members in bending, and offer a solution to the design code alterations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the organizing committee of SCESCM 2016