The Keystone KeySystem III retaining wall system was recently evaluated by the Federal Highway Administration’s (FHWA) new Innovations, Developments, Enhancements and Advancements (IDEA) program.
Administered by the American Society of Civil Engineers’ (ASCE) Geo-Institute, the technical evaluation of Keystone KeySystem III serves to help advance earth retention systems technology and the process for installing those systems.
Structural applications for these systems include retaining walls, headwalls/wingwalls, bridge abutments and roadway support on government, transportation, commercial, industrial, recreational, public works and residential projects.
Keystone KeySystem III is designed to the highest standards and unique requirements of the transportation sector. The system is comprised of dry-cast concrete Keystone Compac III modular units and NTPEP-evaluated TenCate Miragrid XT polyester geogrid soil reinforcement by TenCate Geosynthetics.
The leading commercial retaining wall product on the market, Keystone Compac features an open core design and a pin connection system. The Keystone KeySystem is approved or accepted for use by 30 state highway administrations.
The IDEA assessment updates a 2012 evaluation of Keystone KeySystem II by the ASCE’s Highway Innovative Technology Evaluation Center (HITEC). The evaluation considered material, design, construction, performance and quality assurance information provided by Keystone against state-of-the-practice criteria outlined in the IDEA protocol.
For submittal purposes, the design methodology used for KeySystem III follows the current AASHTO LRFD Bridge Design Specifications (AASHTO, 2010 with current interims) and FHWA guidelines for Design and Construction of Mechanically Stabilized Earth Walls and Reinforced Soil Slopes (FHWA, 2009a).
Updates to Keystone KeySystem III include improved Keystone Compac III design features and updated information on soil reinforcement. This is the first update evaluation of a previous HITEC evaluation to IDEA for a system with concrete modular block paired with extensible reinforcement.