Example R02.1: Remove HMA and Replace

In this design alternative, all of the existing HMA will be removed and replaced with the same thickness of new asphalt concrete. The question to answer is whether this is a viable option.

Similar to the inside lanes, the first option to try is with 0.2 ft of RHMA-G and 0.45 ft of HMA, if it doesn't work then try to replace the surface with a mix with polymer modified binder:

•Option 1: 0.2 ft RHMA-G over 0.45 ft of HMA with PG70-10 binder

•Option 2: 0.2 ft of HMA with polymer modified binder over 0.45 ft of HMA with PG70-10 binder

Option 1: 0.2 ft RHMA-G over 0.45 ft of HMA with PG70-10 binder

To evaluate this option, save a copy of the baseline trial under a new name "SBL3_540-495: Remove HMA and Replace".

The project input, simulation parameters, and the simulation results are shown below. Note that in this case Layer 3 and Layer 4 are marked as cracked to account for reflection cracking, otherwise the compute engine will return an error.

As one can see, the design is sufficient.

Option 2: 0.2 ft of HMA with polymer modified binder over 0.45 ft of HMA with PG70-10 binder

To evaluate this option, replace the surface material with the mix with polymer modified binder using the "Edit" link for the RHMA-G layer. The project inputs and the simulation results are shown below. As show in the figure, this option satisfies the design requirement as well.