Concrete placement work to repair or replace a concrete barrier walls damaged by aging or vehicle crash may require traffic restrictions to be imposed over a long period while the section is being worked on. A variety of pre-cast concrete barrier curbs are available in the market. However, most of these curbs end up being manufactured without due consideration to the need of replacement after they are damaged due to aging or vehicle crash. As a solution to such issues, EMC (Easy Maintenance and Construction) concrete barrier walls have been developed with due consideration to workability (ease of installation) and maintainability (ease of replacement).
By using pre-cast materials as well as replaceable bolts to attach materials to the floor slab and to each other, workability can be improved as compared to the cast-in-place concrete barrier curbs, and the number of steps involved in the work can be reduced to 1/5th of which are normally required. Moreover, the curbs have been designed in such a way that even if an unforeseen amount of load is exerted on the curb, the base of the curb is the first part to break, thus preventing damage to the floor slab. In addition, bolted connections ensure easy replaceability and improve maintainability. The bolts used have been made rustproof, and parts of the joints filled in with shrinkage-compensating mortar have been sealed to prevent the entry of water, thus improving the durability. Furthermore, as the work of installing curbs is done mostly on the floor slab alone, the need of erecting and later dismantling scaffoldings and protective structures is vastly eliminated, thus improving the work safety.
<Structural Overview of EMC Barrier Curbs>
A Static Loading Test and Full-scale Crash Test were conducted to check whether the EMC Barrier Wall satisfies the strength and performance requirements of guard rails. In the Static Loading Test, the structure was tested and confirmed to have approx. 4 times load bearing capacity against the designed impact load. In the Full-scale Crash Test, an impact equivalent to that created by a 25-t truck colliding with the structure at an impact angle of 15 degrees at a speed of 65 km/hour was simulated. The structure was confirmed to satisfy all the requirements with no drop in performance.
<Actual Vehicle Crash Test>
