Publications

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2011
Punching of flat slabs with in-plane forces, Ramos, Pinho A., Lúcio Válter J. G., and Regan Paul E. , Engineering Structures, Volume 33, Number 3, p.894–902, (2011) AbstractWebsite

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Punching Research at Universidade Nova de Lisboa, a Ramos, Lúcio V., Faria D., and Inácio M. , Design Of Concrete Structures and Bridges Using Eurocodes, Bratislava, (2011) Abstract

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Sistemas de Reforço de Lajes Fungifirmes, Faria, Duarte, Lúcio Válter, and Ramos António , SILE2011 -Seminário Internacional sobre Ligações Estruturais, Lisbon, p.1–10, (2011) Abstract

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Strengthening of flat slabs with post-tensioning using anchorages by bonding, Faria, Duarte M. V., Lucio Valter J. G., and Ramos Pinho A. , Engineering Structures, Volume 33, Number 6, p.2025–2043, (2011) AbstractWebsite

This work aims to study a new flat slab strengthening technique based on post-tensioning with anchorages by bonding using an epoxy adhesive. The main advantages of this technique over the traditional prestress strengthening systems that use mechanical anchorages are that it does not need external permanent anchorages, meaning that the forces are introduced into the concrete gradually instead of being localized, thereby preserving aesthetics and useable space. The seven tested slab models show that this technique meets its objective as it is able to reduce reinforcement strains at service loads by up to 80{%} if the strengthening technique is applied in two directions and slab deformations by up to 70{%}, consequently making crack widths smaller. It can also increase punching load capacity by as much as 51{%} when compared to non-strengthened slabs. The results are compared with the EC2 (2004) [20], ACI 318-08 (2008) [23] and MC2010 (2010) [21] provisions. The main conclusions are that this strengthening technique is effective regarding ultimate and serviceability states and that it represents an advance in RC slab strengthening techniques. ?? 2011 Elsevier Ltd.

2010
Bond Behaviour of Prestress Steel Strands Bonded with an Epoxy Adhesive and a Cement Grout for Flat Slab Strengthening Purposes – Experimental Study, Faria, Duarte, Ramos António, and Lúcio Válter , 3rd fib International Congress - 2010, Washington, p.1–10, (2010) Abstract

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Punching of reinforced concrete slabs and experimental analysis and comparison with codes, Faria, Duarte, Biscaia Hugo, Lúcio Válter, and Ramos António , IABSE-Fib Codes in Structural Engineering – Developments and Needs for International Practice, Dubrovnik, p.1–10, (2010) Abstract

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2009
Strengthening of reinforced concrete flat slabs using post-tensioning with anchorages by bonding, Faria, D. M. V., Lúcio V. J. G., and Ramos A. M. P. , Fib symposium–concrete: 21st century superhero, London, London, (2009) Abstract

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2008
Estudo Experimental do Punçoamento Cíclico em Lajes Fungiformes Reforçadas com Pré-Esforço Transversal, Luis, Marta, and Ramos António , Encontro Nacional Betão Estrutural 2008, Guimarães, (2008) Abstract

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Post-punching behaviour of prestressed concrete flat slabs, Ramos, Pinho A., and Lúcio V. J. G. , Magazine of Concrete Research, Volume 60, Number 4, p.245–251, (2008) AbstractWebsite

The progressive collapse of structures generally results in the loss of human lives. Experience shows that flat slab structures are very sensitive to progressive collapse, which may cause serious accidents if special detailing is not provided. The post-punching behaviour of a column-supported slab is decisive in the progressive collapse development. This work presents the experimental research carried out to study the post-punching behaviour of prestressed concrete flat slabs. Six reduced-scale prestressed concrete flat slab models were tested. The tests were carried out in two different phases. In the first phase the models were loaded up to failure by punching. Afterwards, the models were loaded again to study the post-punching behaviour changes caused by the presence of unbonded, prestressed tendons and the influences of their distance to the column.

Reforço de Lajes Fungiformes – Anomalias, Causas e Soluções, Lúcio, Válter, Ramos António, and Faria Duarte , SILE2008 – Seminário Internacional sobre Ligações Estruturais, Lisbon, p.1–10, (2008) Abstract

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Rehabilitation of Historical Masonry Bridges, Rodrigues, Neuza, Ramos António, and Branco Fernando , 1st International Conference Construction Heritage in Coastal and Marine Environments – Damage, Diagnostic, Maintenance and Rehabilitation, Lisbon, p.1–10, (2008) Abstract

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Strengthening of flat slabs with transverse reinforcement, Duarte, Inácio, Ramos António M. P., and Lúcio Válter J. G. , Proceedings of CCC, Porto, (2008) Abstract

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2007
Comportamento Pós-Rotura de Lajes Fungiformes Pré Esforçadas, Ramos, António Pinho, and Lúcio Válter , Revista Portuguesa de Engenharia de Estruturas, Volume 1, Number Série II, p.5–14, (2007) Abstract

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2006
Resistência ao Punçoamento de Lajes Fungiformes Pré-Esforçadas - Método Alternativo de Cálculo, Ramos, António, and Lúcio Válter , Revista Internacional Construlink, Volume 4, p.4–14, (2006) Abstract

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Safety on Punching of Prestressed Flat Slabs, Ramos, António, and Lúcio Valter , fib congress 2006, Naples, (2006) Abstract

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2004
Estudo Experimental de Punçoamento em Lajes Fungiformes Pré Esforçadas, a Ramos, and Lúcio V. , Encontro Nacional Betão Estrutural 2004, Porto, (2004) Abstract

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2000
Punching of prestressed flat slabs: Experimental analysis, Ramos, A. M. P., and Lúcio V. J. G. , International Workshop on Punching Shear Capacity of RC Flat Slabs, Volume 57, Stockholm, p.441–448, (2000) Abstract

The experimental analysis of nine prestressed flat slab models under punching is described and the results are compared with the recommendations of EC2 and MC90. The tests were performed on specimens at a scale 1/3, prestressed with unbonded high strength steel. In the first set, the specimens (AR2 to AR5 and AR7) were only subjected to in-plane compression, to evaluate the effect of the in-plane forces on the punching resistance. The second set of tests (AR8 to AR11) intended to study the effect of the vertical component of the tendon forces near the column in the punching resistance. This work aims to improve the understanding of the behaviour of prestressed flat slabs under punching load and the evaluation of the punching resistance.

Repair and Strengthening Methods of Flat Slabs for Punching, Ramos, Antonio, Lucio Valter, and Regan Paul E. , International Workshop on Punching Shear Capacity of RC Flat Slabs, Stockholm, p.125–133, (2000) Abstract

The present work reports experimental research carried out on repair and strengthening methods of flat slabs for punching. The repair and strengthening methods studied are: strengthening using transversal prestress, repair by substitution of the damaged concrete; and strengthening using steel beams as a column head, connected to the column and to the slab with epoxy resin and mechanical expansion anchors. Four experimental test slabs (AR1 to AR4) were produced and tested: two with transversal prestress, one only repaired and one strengthened with a steel column head. The execution process, its efficiency and design, are discussed.