AASHTOWare DARWin Modules

darwin modules

The *Flexible Structural Design Module* can be used to design and analyze asphalt concrete pavements using three methods—layered analysis, specified, and optimized design. Based on the design inputs, DARWin calculates the required structural number. Alternatively, the process can be reversed to calculate the load-carrying capacity of a pavement for a given structural number. Options are also available to calculate the required inputs. Sensitivity plots can be generated to illustrate graphically the effect of varying primary inputs.
The *Rigid Structural Design Module* is used to design and analyze portland cement concrete pavements. DARWin directly calculates the required slab thickness based on the given design inputs. The features found in the Flexible Structural Design Module, such as sensitivity plots and calculation options, are also available. This module can also be used to design other rigid pavement features, including steel reinforcement, tie bars, and joint reservoirs.

Seven different overlay types can be designed in the *Overlay Design Module: AC overlay of AC pavement, AC overlay of fractured PCC pavement, AC overlay of PCC pavement, AC overlay of AC/PCC pavement, bonded PCC overlay, unbonded PCC overlay, and PCC overlay of AC pavement. Each overlay can be designed using up to three different methods—component analysis, nondestructive testing, and remaining life. The Overlay Design Module* also contains analytical routines to perform backcalculation and calculate deflection load transfer using falling weight deflectometer (FWD) data.

The *Life Cycle Cost Module* is a comprehensive analytical tool that can be used to compare alternative designs. All costs are considered in the analysis, including initial construction costs, maintenance costs, rehabilitation costs, and salvage costs. The results can be output using different evaluation methods (net present value or equivalent uniform annual cost) and different cost parameters (total cost or cost per unit length in one or two directions). Cash flow diagrams are generated automatically for each project.