In 2005 ULB launched the LOCK-BLOCK® brand into the next dimension as we patented a completely new method of building Roman arch bridges, tunnels and vaults.

The Romans had to clear cut forests to build the temporarily supports to build their massive arched stone structures. We figured out a better way to do the same thing without this formwork.

View a YouTube video of some storm water detention vaults (Wiki) that were built at a concrete plant in Surrey BC..

This video shows a crew assembling three vaults over a five day period. The crew got faster as the job progressed and the final vault was assembled in only eight hours!

That’s 35 feet of tunnel completed in a single working day or 4.4 lineal feet per hour!  

The area over the vaults is now used to park concrete trucks.

The ARCH-LOCK® method eliminates falsework. The copyright protected interlocking key design holds the units together in alignment during and after assembly. The ARCH-LOCK® voussoirs achieve geometric and fit tolerances with repeatability through precise precast concrete forming techniques. This precision eliminates the need for the mortar the Romans required to overcome dimensional and geometric variations typical of cut stone voussoirs.

By eliminating these factors the ARCH-LOCK® system can provide the high strength, beauty and durability of a Roman arch bridge or vault at a fraction of the cost and the time required to build a comparable conventional reinforced post and beam concrete structure.

You can download a PDF detailing discussion of  The Roman Arch & ARCH-LOCK® at this link.

Besides these storm water detention vaults the ARCH-LOCK® system is ideal for...

Highway Overpass Bridges, Underpasses, Bike, Pedestrian and Wildlife Crossings Railroad, Light rail, Bus and Subway Tunnels Wine and Root Cellars Military Bunkers Bomb and Tornado Shelters Earth Sheltered Residences, underground Utility Buildings, Garages Conveyor and Material Reclaim Tunnels Electrical Vaults and cable conduits Bottomless Culverts for stream and ditch crossings over sensitive fish habitat areas Logging Truck Bridges temporary and permanent Temporary site access and permanent Pipeline and Utility crossings Decorative entrance arches

The main features and benefits of ARCH-LOCK® construction are...

Speed – Precast sections are pre-cured, chain restraint system allows rapid assembly Simplicity – Only four rugged shapes are required to build a vault. Strength – Arches are one of the strongest structures in compression known Stability – Seismic stability of arches is well known, many are still standing from antiquity Durability – No rebar, no corrosion, maintenance free life, resistance to chlorides Aesthetics – Custom art & lettering are easily cast into the inside & facing surfaces Low tooling costs - Various shapes can be easily combined to produce tailored profiles This system is highly competitive against... Multi-Plate® Steel culverts and vaults Precast concrete bridge and tunnel construction Structural Steel bridge construction Timber bridges