Shearband System (marketed by ERICO as LENTON® STEEL FORTRESS)

The most innovative and effective solution to Punching Shear ever devised

Shearband System


The Shearband system is a high tensile and high ductility thin metal strip and differs from all existing systems. The system can be placed on top of all other reinforcement, with minimal loss of cover. This has huge benefits such as:

  • simple and efficient placement of reinforcement

  • anchors to the uppermost layer of reinforcement

  • it acts over the entire concrete core

  • it is an adaptable system that can accommodate greater tolerances in placement

  • and simply and uniquely enables quick addition of extra reinforcement where required

Placement of Shearband around column


In addition:

  • it can be designed by using the existing design codes

  • it can be used in addition to other systems

  • it is light, requires only man-handling

  • it is easy to store on or off site

  • it can allow for the design of thinner slabs with all the added benefits

  • all the reinforcement placed is useful

  • there is no undesirable increase in the slab’s flexural capacity

Hence, the Shearband system provides:

SPEED, ECONOMY, EFFICIENCY, RELIABILITY, SIMPLICITY, ELEGANCE

For more information, please contact Professor Kypros Pilakoutas, Tel +44 – 114 – 2225065

email : k.pilakoutas@sheffield.ac.uk

Shearband Background Information

"Concrete flat slab floors provide an elegant form of construction, which simplifies and speeds up site operations, allows easy and flexible partition of space and reduces the overall height of buildings."

Problem of Punching Shear

Flat slab construction is not ideal from the structural point of view, due to stress concentration at points of support, such as columns. In reinforced concrete design, the problem is a matter of preventing brittle punching shear failure.

Reinforcing against shear failure is traditionally accomplished by providing reinforcement either at an angle or laterally to the main flexural reinforcement.

In thin structural elements, such as slabs, anchoring short lengths of shear reinforcement can not be placed above the top layer of flexural reinforcement without reducing either the durability, or efficiency of the flexural reinforcement. In addition, there is the practical problem of supporting shear reinforcement during the construction stages.

Experimental Proof

Puncing shear failure of flat slab (without Shearband - PSSA)

The Shearband has been developed after extensive research at the Centre for Cement and Concrete of the University of Sheffield. Tests were carried out in two Phases on eight RC slabs subjected to 8 point loads equidistant from the column.

Following the initial phase of testing, independent assessment of the experimental work was performed.

The results showed that Shearband may change the mode of failure to a ductile flexural mode. Measured strains developed in the flexural reinforcement exceeded 2%. Further tests were carried out on beams to determine the effectiveness of Shearband on more isolated situations.

One test was also carried out on a slab with large openings adjacent to the column. This slab was also reinforced with the Shearband and, despite code predictions, failed in a flexural manner at the predicted load by the yield line method.

Experimental results obtained for flat slabs