Compressive membrane action in concrete decks

Compressive membrane action in concrete decks

Amir, S.

Civil Engineering and Geosciences

Structural Engineering

2012-12-31

One of the major challenges facing the designers today is to investigate if the old bridges are still safe for modern traffic. The current research deals with this question by taking into account compressive membrane action (CMA) in determining the capacity of reinforced and transversely prestressed con-crete decks. CMA can significantly affect the flexural and punching shear strength of deck slabs but it is usually neglected for design and assessment purposes. Therefore, a flexural theory was used and a punching shear model was modified to fully utilize the effect of strength enhancement by CMA. Several experiments done by various researchers have been analysed by using these theories. It was concluded that considering CMA in the assessment shows that bridge decks can have a considerably larger shear capacity than assumed in the initial design. This is of high significance because in The Netherlands about 70 bridges have to be investigated, with very thin decks cast between the flanges of long prestressed beams. Using the actual design codes for the verification of the bearing capacity leads to values showing that the safety standards are not met. However, theoretical analyses show that nevertheless sufficient residual capacity might be available. In order to confirm the validity of the calculations large scale laboratory tests are carried out. Variables are the geometry of the deck, the confining effect on the punching shear capacity, and the role of transverse prestressing.

http://resolver.tudelft.nl/uuid:a9f822c5-7156-476a-81fe-e27d35fbc7e4

KIT Scientific Publishing

978-3-86644-858-2

Proceedings of the 9th fib International PhD symposium in Civil Engineering, Karlsruhe, Germany, 22-25 July 2012

Institutional Repository

conference paper

(c)2012 Amir, S.