Structural Concrete, Vol. 4, no. 2, June 2003

Written on 19 August 2011.

Theoretical model for the determination of plastic rotation capacity in reinforced concrete beams

R. N. F. do Carmo, Department of Civil Engineering, ISEC-Polytechnic Institute of Coimbra Portugal
S. M. R. Lopes, Department of Civil Engineering, FCTUC-Polo II-University of Coimbra Portugal
L. F A. Bernardo, Department of Civil Engineering, University of Beira Interior Portugal

Evaluating the ducility of reinforced concrete beams is essential in order to avoid a fragile collapse of the structure by ensuring an adequate deformation at ultimate load. This paper presents a theoretical model for the calculation of plastic rotation. Results obtained are compared with those obtained from an experimental programme in which a set of beams were tested to failure. From the comparison, a good agreement between theoretical and experimental results was achieved. The proposed theoretical model considers the influence of certain factors: steel properties, concrete strength, section depth, and the tension stiffening effect. Concrete strength, particularly, is an interesting parameter since for high-strength concrete, the ultimate concrete strain, εcu, decreases as the concrete strength increases.

Structural Concrete, Vol. 4, no. 3, September 2003

Written on 19 August 2011.

Durability of concrete structures

Catherine French, University of Minnesota, USA

This paper provides a brief overview of Session 8 'Durability of Concrete Structures' of the fib 2002 congress on Concrete Structures in the 21st Century, which was held in Osaka on 13-19 October 2002. The keynote speaker of the session, Dr Odd E. Gjørv, Professor and Head of the Department of Building Materials at the Norwegian University of Science and Technology at Trondheim, has conducted concrete research for more than 40 years. His research has focused on a broad range of topics related to the durability of reinforced and prestressed concrete structures in severe environments. His paper addressed durability and service-life issues of concrete structures. In addition to the keynote address, more than 50 papers were considered for this session, covering topics in the following areas: general issues related to concrete serviceability and durability, corrosion of reinforcement, and grouting of post-tensioned systems, as well as several case studies. The highlights of some of the papers are described here.

Structural Concrete, Vol. 4, no. 2, June 2003

Written on 19 August 2011.

Structural behaviour of steel fibre reinforced concrete

I. Kovacs, College Faculty of Technology, Department of Civil Engineering, University of Debrecen, Hungary
G. L. Balazs, Budapest University of Technology and Economics, Department of Construction Materials and Engineering Geology, Hungary

Results of an experimental study on 21 fibre reinforced concrete beams indicate that steel fibres do not only increase shear capacity but also provide substantial post-peak resistance and ductility in conventionally reinforced beams as well as in prestressed pretensioned concrete beams. The tests were carried out on 2m long beam specimens reinforced with longitudinal bars and fibres. Test variables were amount and type of fibres, amount of stirrups and type of longitudinal reinforcement (prestressed or non-prestressed).

Structural Concrete, Vol. 4, no. 2, June 2003

Written on 19 August 2011.

Structural behaviour of steel fibre reinforced concrete

I. Kovacs, College Faculty of Technology, Department of Civil Engineering, University of Debrecen, Hungary
G. L. Balazs, Budapest University of Technology and Economics, Department of Construction Materials and Engineering Geology, Hungary

Results of an experimental study on 21 fibre reinforced concrete beams indicate that steel fibres do not only increase shear capacity but also provide substantial post-peak resistance and ductility in conventionally reinforced beams as well as in prestressed pretensioned concrete beams. The tests were carried out on 2m long beam specimens reinforced with longitudinal bars and fibres. Test variables were amount and type of fibres, amount of stirrups and type of longitudinal reinforcement (prestressed or non-prestressed).

Structural Concrete, Vol. 4, no. 2, June 2003

Written on 19 August 2011.

Message from the President Jim Forbes, President of the fib

No abstract

Structural Concrete, Vol. 4, no. 1, March 2003

Written on 19 August 2011.

The power of prestressing

Jiri Strasky, Technical University of Brno, and Strasky Husty and Partners, Brno, Czech Republic

The idea of prestressing - a product of the twentieth century - has announced the single most significant new direction in structural engineering of any period in history. It put into the hands of the designer an ability to control structural behaviour and, at the same time, it enabled the designer - or forced the designer - to think more deeply about the construction. Moreover, the idea of prestressing opened up new possibilities for a form that influences the general culture. To focus on that fact, and to narrow the scope, the paper will consider bridges only, even though prestressing has broad applications to all kinds of buildings. However, the idea of prestressing arose out of bridge design, and its most impressive forms, from a purely engineering viewpoint, have appeared in bridges.