Sherry Sullivan MASc, P.Eng, LEED AP
Business Development & Pavement Engineering with FORTA
While few spend much time thinking about concrete, it has been at the heart of civilization since before the Romans built the Pantheon. Fast forward to the 21st century and concrete is abundant. It is quite literally the foundation of the modern world, underpinning everything from buildings, to roads, bridges, electricity and water infrastructure, public transit, piers … the list goes on.
There has been much progress with the design and construction of concrete pavements, since the first was built in 1865 in Inverness, Scotland. Considerable research continues and concrete pavement technology continues to advance. One of the most disruptive innovations in concrete pavement design and construction history- for improving long-term performance, significantly reducing costs and improving environmental sustainability – is the OptiPave System™ by TCPavements™, also known as short-panel concrete pavements.
In 2005, a revolutionary methodology to design concrete pavements was developed, concrete slabs with optimized geometry, now known as the TCPavements OptiPave System. This technology is based on designing the dimension of the concrete panels so that no more than one wheel or set of wheels will be loading the same panel at any time. This causes the panels to work in a different way than usual, decreasing stresses and allowing a reduction in thickness when compared to concrete pavements that were designed using traditional methods – all without reducing its lifespan and increasing its fatigue resistance.
Pavements designed and constructed with the OptiPave System curl less and provide a smoother ride than traditional designs. Besides the lower initial cost, the reduced material requirement also significantly improves the pavements sustainability. The reduced material requirement can also provide a reduction in construction time, reported on many projects to be more than 20% compared to traditionally designed concrete pavements.
This technology is further enhanced by the use of macrosynthetic fiber, FORTA-FERRO®, which improves the residual strength of the concrete, structural capacity of the pavement and allows for further reduction of the pavement thickness. The addition of this macro synthetic fiber also gives better performance over its lifetime in the post-cracking stage. It also controls cracking settlements due to possible inhomogeneities in the supporting surface of the concrete panel.
To evaluate the OptiPave System, full-scale test sections were constructed and tested at the University of Illinois, using accelerated loading conditions. The performance data from this full-scale test were utilized in the development of the mechanistic-empirical design software, OptiPave2™. The OptiPave2 software is specifically tailored to design short panel concrete pavements for any set of climates, traffic, subgrade/subbase layer, and material property inputs, including the addition of residual strength through the use of macrofibers. These test results, along with nearly 20 years of field performance in real projects, have served to validate the OptiPave System and calibrate the design software, OptiPave2
In 2017, ACI 330.2R-17 (American Concrete Institute) included the technology as a design alternative to optimize concrete pavements for industrial and trucking facilities. The Global use of the OptiPave System has grown over the past 18 years with projects being constructed in many countries, including Australia, Bolivia, Canada, Chile, Colombia, Costa Rica, France, Guatemala, Mexico, Nicaragua, Perú, South Africa, Spain, United States, among others.
Here in the United States, a large building product supplier’s distribution center features over 3.0 million ft2 (250,000 m2), making it the largest project to be constructed in the world using the OptiPave System. This project has provided the owner with significant cost savings and will deliver a very durable and long-lasting concrete pavement.