LENTON® STEEL FORTRESS is a shear reinforcement system that provides a simple solution to the complex problem of brittle punching shear. LENTON STEEL FORTRESS consists of a continuous flat steel strip that has holes punched along its center and is pre-bent in the plant into a custom-shaped profile to fit over the top of the flexural reinforcement bars in the concrete slab. The steel strips in the LENTON STEEL FORTRESS System meet or exceed ASTM A505-87 requirements with a minimum yield strength of 72,500 psi (500 MPa) and a minimum elongation of 11%.

The LENTON STEEL FORTRESS System is supplied to the site individually boxed on a per column basis and is custom made to meet your specific application needs. Because the product installs over the uppermost layer of main reinforcing bars, placement is fast and easy. This placing method accommodates unexpected design changes and makes on-site inspection simple. In addition, the horizontal length of the system provides ample space to accommodate irregular rebar placement.

The capability of the LENTON STEEL FORTRESS System to anchor to the top tier reduces the possibility of the induced shear cracks bypassing the shear reinforcement, thus preventing brittle punching shear failure. Because the LENTON STEEL FORTRESS can encapsulate the upper layer without unduly affecting cover, it overcomes the inability to anchor over the uppermost tensile reinforcement layer that some other systems encounter.  

The LENTON STEEL FORTRESS has many advantages over other traditional and proprietary punching shear reinforcement systems. It minimizes the need for stud reinforcement systems, column capitals, drop panels and additional stirrups. It also optimizes flying forms, saves time and labor by going in after the rebar is placed, and is exceptionally lightweight and cost effective. In addition, the system develops its yield strength over a much smaller length, enabling it to be used in thinner concrete slabs.

The product is patent protected, ICC®-ES recognized: Report ER-5668 and certified by the City of Los Angeles Report RR25486. It conforms to ACI 318.02, as well.