The market for new precast concrete products is evolving all the time.
Changing government policies—as well as an increase in consumer demand—have created technology gaps that the concrete industry needed to fill. In response to these changing market demands, the industry has responded with renewed investment in precast concrete technology.
The growing market for precast boxes and culverts is a great example. Not that long ago, the largest precast box you’d find on the market was 3.6m x 3.6m (12ft x 12ft). However, customers found that larger structures could accelerate their construction schedules. Thus, the industry responded with
bigger precast boxes sized 6m x 4m (20ft x 13ft). Concrete pipe producers ran with this idea and designed multi-cell box culverts to further speed up construction. Today, triple 2.4m x 2.4m (8ft x 8ft) reinforced concrete box culverts are available across the world.
Precast components can now include arches or boxes for storage, protection of utilities and services, and small bridges. The increase in larger precast systems, of course, requires production of other new products (such as slabs and beams) to complete drainage and storage structures. But as the industry continues to grow, we expect concrete pipe producers to continue to innovate these new types of products to support construction efficiency.
Precast boxes for culverts provide a cost effective structural product with excellent flow characteristics for use in streams. In addition, they are used for small bridges, access tunnels and onsite detention systems.
Precast boxes are a versatile product and easily adaptable to many different configurations allowing them to be used primarily as culverts, but also chambers, manholes, lift stations, pedestrian underpasses, fish ladders, or almost any use an engineer or designer can imagine.
Designed and engineered to meet standard box units found in OPSS 1821 or ASTM C1443 specifications, precast boxes must accommodate Canadian Highway Bridge Design Code requirements, while satisfying specialized loadings, and/or addressing many different design considerations.
Construction of a 50km alignment of Highway 407 from Brock Road to Highway 35/115 in Clarington, Ontario is scheduled for completion in 2020. The highway system is comprised of numerous structures and interchanges including culverts to support high-speed lanes and accommodate the hydraulics of streams and drainage systems. The supply of large-sized precast concrete boxes for the construction of culverts to convey tributaries of Oshawa Creek was accelerated by using pre-assembled rebar cages during production of the boxes. The cages were supplied by StelCrete Industries Limited, fully certified by the Canadian Welding Bureau. The boxes were produced by M Con Pipe & Products Inc. in Ayr, Culverts (M51 – Oshawa Creek West Tributary and M56 – Oshawa Creek East Tributary) were specified originally as cast-in-place structures. Culvert M-51 was designed as an 8000mm span x 2500mm rise culvert, and M56 an 8000mm x 2100mm structure. Top and bottom slabs and walls were required to be 800mm thick.
See the article in the Summer 2014 Issue of the Concrete Pipe Journal on Page 6.
Precast concrete manholes are the standard product used to provide vertical access to buried pipelines, vaults, detention tanks and various other structures. They are manufactured using modern drycast concrete technology. Manholes are installed using gaskets to provide a watertight product and to reduce infiltration into storm or sanitary systems.
Manholes are provided with cast-in lift inserts for safe, easy installation, ladder rungs for access, and are available in standard 1200mm, 1500mm, 1800mm, 2400mm, 3000mm, and 3600mm diameter sections.
Advantages of Round Manholes over Square and Rectangular Shapes. The use of square and rectangular manholes is becoming common, as more sizes of flat-walled structures are created, promoted, and installed beneath street rights of way. When looking toward the new shapes, we tend to forget about the benefits of the classic circular manhole that serves
the infrastructure industry very well.
Long span precast boxes and arches are available for replacing small bridges. Boxes and arches come in a range of
sizes and configurations to fit site conditions. A precast concrete bridge replacement can provide maintenance-free
service for decades, even for as long as 100 years, as the concrete get stronger with time. Members of the Canadian
Concrete Pipe & Precast Association offer reliable, high-quality products for small bridge systems.
A CON/SPAN® bridge was assembled in less than two days to replace an aging timber bridge on Manitoulin Island; Ontario’s 180 km-long, and world’s largest freshwater island. The first precast structure of its kind on the island spans Grimsthorpe Creek on Grimsthorpe Road between the Sand Road and the Beaver Road, west of Providence Bay. The concrete structure consists of a north cell (10.973m x 2.440m) and a south cell (8.535m x 2.440m) with precast headwalls. The structure width is 21.032 metres. It took five precast concrete arches for the construction of each cell. Each arch has a lay length of 1.829m.