Chilean company, TCPavements (www.tcpavements.com) developed a methodology that employs optimized geometry to calculate and design concrete slabs for pavement projects.

The concept behind the „TCP“ design is that each slab of the pavement is loaded by only one wheel or a set of wheels at the same time. This significantly reduces the top tensile stresses of the slabs. With this configuration of loads versus the dimensions of the slab, the cantilever effect is reduced by the rocking of the slab as the load moves over it, so each slab supports the loads under the wheels, supported on the ground.

To achieve this condition, it is necessary to dimension the slabs in such a way that with a given truck; each wheel, or a set of wheels, loads a different slab at the same time (see Figure 1). As different types of vehicles exist, it is designed for the most harmful, unless the traffic is known and then it is designed for the type of vehicle that will use the road.

Reducing the stresses on the top of the slab allows for a longer lifespan of the pavement, or seen from another point of view, it allows a reduction of the thickness to achieve the same stresses and lifespan obtained in the traditional design.

In Figure 1 – Optimized Slab Design, option 1, it is with TCP® Design where the top stresses or tensions generated by the loads are smaller, so the pavement can be designed with thinner concrete slabs.

The following Figure 2 illustrates the stresses or tensions at the top of the slab, for different geometric configurations of the loads respect to their dimensions. Using ISLAB 2000, we can model different configurations of loads versus sizes and geometries of slabs. All other variable (Soil, LTE, Temperature Gradients, etc) are kept the same.