CS-R01 Design Summary

The designs considered in this example illustrate several design options to rehabilitate a severely distressed section of IN395 with a weak subgrade. The design options ranged from strategies where none of the existing distresses are removed, to strategies that increasingly removed distresses to deeper depths while stabilizing underlying materials to create a stronger foundation. The total thickness of HMA (HMA-PM, intermediate HMA and rich-bottom HMA) are summarized in the figure below to illustrate the reduction in new HMA requirements for different strategies to carry the design traffic, along with the new materials introduced. The design examples show the following:

Using FDR or CCPR can significantly reduce the total HMA required. LCA and LCCA are required to evaluate the alternatives to rank them both in cost and sustainability respectively.

Using CSS to stabilized the subgrade can change the failure mode from rutting to cracking

Figure 16: Thickness for layers used in each design alternative