Marco Jorge

Full-Scale Experimental Testing of Retrofitting Techniques in Portuguese “Pombalino” Traditional Timber Frame Walls

Traditional timber frame walls are constructive elements representative of different timber frame buildings, well known as efficient seismic-resistant structures. They were adopted as a seismic-resistant solution in Lisbon’s reconstruction after the 1755 earthquake. To preserve these structures, a better knowledge of their seismic behavior is important and can give indications about possible retrofitting techniques. This article provides a study on possible retrofitting techniques adopting traditional solutions (bolts and steel plates). Static cyclic tests were performed on retrofitted traditional timber frame walls. The experimental results showed the overall good seismic performance of steel plates and the more ductile behavior of bolts retrofitting.

Repairing of a timber truss through two different techniques using timber elements and screwed metal plates

Structural reinforcement of timber buildings may be needed due to different reasons such as change of use, deterioration due to lack of maintenance, exceptional damaging incidents or loading, after changes in regulatory specifications, or interventions to increase structural resistance. In this work, two different techniques were considered for repairing a timber truss that was previously assessed on laboratory (test facilities of University of Minho) and taken up to failure during a load-carrying test. A collar beam truss, with more than one hundred years, was tested considering a vertical point load on each main rafter. Failure of the timber truss was located in the sections of the rafters near the loading positions by bending. Repairing techniques, based on the use of timber elements for one of the rafters and on screwed metal plates for the other rafter, were evaluated and compared to the original unstrengthened condition. The efficiency of the combined repairing techniques was evaluated taking into consideration the structural performance of the collar truss, namely its displacement and ultimate load capacity. In this paper, the results of the experimental tests are discussed attending to the analytical calculation of the contribution of the repairing techniques. Also, the different failure scenarios, for original and strengthened truss, were analyzed and compared.

FP1101 and RILEM TC 245 RTE Training School on Assessment and Reinforcement of Timber Elements and Structures: The Role of the Academic Community in Disseminating Knowledge

In the past decades, timber has been considered as a secondary construction material owing to the emergence of other materials such as concrete and steel, and as a consequence a large amount of knowledge on how to use timber has been forgotten or even lost. This has led to badly designed interventions on timber structures, which have misinterpreted the past structural solution and led to significant structural performance problems. However, the European research community has made a significant effort towards the dissemination of knowledge regarding the design and assessment of timber structures. Within that scope, COST FP1101 had the objective of increasing the acceptance of timber in both the design of new structures, as well as in the repair of old buildings by developing and disseminating methods to assess, reinforce and monitor them. To that aim, FP1101 and RILEM TC 245 RTE in collaboration with the University of Minho (Portugal) organized a Training School (TS) on the assessment and reinforcement of timber elements and structures during 11–14 May, 2015. The training school had the objective of disseminating knowledge to young researchers, as well as to others interested in wood and timber construction and the rehabilitation market. During the TS, several experts provided information on the assessment of existing timber structures, visual grading, interventions on heritage buildings and on analysis, repair and reinforcement of traditional and dowelled timber connections and structures. Also, full-scale tests on an old timber trusses and on connections were made examining both the original conditions and post failure reinforcement. This work presents the different areas of knowledge that were scope of that training school and its main achievements on the dissemination of knowledge to young researchers and other interested groups.

Double Span Continuous Glulam Slabs Strengthened with GFRP

Full-scale slab strips were tested in order to analyze the flexural response of GFRP-glulam slab systems under monotonic loading. The type of strengthening technique (externally bonded reinforcement - EBR and near-surface mounted - NSM) and the increase target in terms of ultimate load capacity (20% and 40%) were the main studied parameters. GFRP sheets were utilized in the EBR technique, while GFRP rods were applied in NSM technique. In this work the tests are described in detail, and the obtained results are presented and discussed.