Strengthening by CFRP strips of two-way reinforced concrete slabs supported on bearing walls

Abstract EN

This paper presents an experimental investigation on the strengthening of two-way reinforced concrete slabs.

Thirteen two-way reinforced concrete slabs with size of 1500x1000x50mm simply supported along four edges were tested.

In addition to the edge support, two of the control specimens were tested and five of the slabs were preloaded with the existence of an interior support at mid line parallel to the short edge.

They were loaded through two points placed at the center along the short direction and one forth from the exterior support along the long direction.

The main variables studied were the steel reinforcement ratio (0.2% and 0.4%), Carbon Fiber Reinforced Polymers (CFRP) strip spacing (200 and 300mm c/c), strengthening condition (strengthened and preloaded) and support conditions (with and without interior support).

The test results confirmed that applying CFRP strips as strengthening material can improve the load carrying capacity of the slabs up to 331% compared with the control specimens.

The distinct result was that the application of CFRP strips can lead to the removal of the interior support (enlarging the panel area), the finding which allows changing the function of existing buildings.

The yield line theory was used for theoretical evaluation and good agreement was found with experimentalresults.