Anchor Concrete Products Limited to receive NPCA Award
CCPA producer member Anchor Concrete Products Limited finished first for the Creative Use of Precast Award by the National Precast Concrete Association. Anchor will be honoured at The Precast Show Industry Awards luncheon on March 1 at 1:30 at the Orange County Convention Center in Orlando.
The award is for the Bombardier Monorail Test Track which represents the future of transportation – high speed mass transit. Bombardier Transportation Systems is a world leaders in this area. Their BOMBARDIER* INNOVIA* Monorail 300 system (Trademark(s) of Bombardier Inc. or its subsidiaries) requires a very exacting monorail to achieve the ride Bombardier's customers expect.
Bombardier Transportation Systems invited Anchor and several other precasters to enter into a competitive bid for the supply of 1.8km (1.125 miles) of precast concrete track. Based on cost and technical compliance, Anchor was awarded the contract to manufacture and supply the beams.
The monorail test track was required for the testing of a new generation of monorail cars. To achieve the foregoing and serve as a test bed for monorail projects in Saudi Arabia and Brazil, the track geometry was intentionally complex. It included a variety of horizontal and vertical curves, along with super-elevated slow and high speed curves with associated transition sections, which proved to be the most challenging.
Anchor produced 166 pieces of 30 tonne (33 tons) reinforced concrete beams incorporating curves, super-elevated curves, and gradient beams with extremely tight tolerances on fit. The first pour was May 12, 2011 and the final pour was October 26, 2011. There were 127 straight beams produced with lengths ranging from 6.69m (22') to 11.6m (38'). Nineteen transition beams (flat surface to super elevated curve) were produced at 10m (33') in length and 20 super-elevated curved beams also at 10m (33') in length. All beams were 0.69m (2' 3") wide and 105m (5') high.
To provide an exceptionally smooth ride, all beams had extremely tight tolerances of +/-lmm (3/64") in a 1.5m (5') straight edge, +/-2mm (3/32") in width at any location and +4/-8mm (3/16" / 3/8") in 11.6m (38/) length. Anchor’s negotiations with two major mould manufacturers eventually failed when both were unable to conform to the exacting precision required within the project time line and budget. Anchor then looked for another economic solution to the variable beam geometry and ultimately ended up achieving this in house by employing many innovations such as:
- Building two straight moulds in tandem to resist deflections during concreting;
- Creating jigs for accuracy and repeatability of rebar cages;
- Suspending rebar cages in the moulds for precise adjustment of cover;
- Producing very detailed drawings for production personnel to assemble the super elevated curved form work;
- Implementing a procedure of how to flip and roll the units to eliminate surface damage;
- Pouring the beams upside down to ensure consistent textured (form liner) finish on the top surface;
- Creating a method to position the beam end bearing connection plates which required a high degree of coordination with the rebar cage due to the quantity of Nelson studs which were used to create the steel to concrete connection;
The greatest challenge was in producing the super-elevated curved beams and the associated transition beams. It was uneconomic to build specific moulds for each type of the 19 special beams required, so a system of proprietary adjustable moulds was designed to provide both spiral curvature and continuously varying super-elevation.
For quality control checks, Anchor implemented a targeting system for lasers, used laser cut templates, calibrated tape measures, and laser measuring devices. Systems of go/no go gauges and a custom designed recording spreadsheet were used to show compliance with tolerances.
Project schedule savings, such as manufacturing all beams prior to the start of installation, creating a rebar jig, using adjustable moulds, and the use of a curing compound after demoulding the beams, ensured rapid turnover and reduced labour costs.
Installation of the monorail track at site was faster than planned. At project planning stage, the installation schedule was for 4 beams per day. Due to the accuracy of both construction and precast elements, 12 to 16 beams were installed some days, reaching as many as 18 installations on the final day. Anchor continues to receive requests for information on its forming process from foreign contractors.
Anchor’s precision with the extremely tight tolerances produced an incredible track. To provide a skid resistant finish to the top running surface, the product was poured upside down and a fine textured form liner was used in lieu of the traditional broom finish. This consistent architectural skid resistant finish on the top running surface of the track will be a large selling point. Anchor Concrete Products Limited suggests that the future use of monorail systems utilizing a smaller foot print coupled with their processes of producing precision concrete beams with complex curves will pave the way for the future of urban transportation.