Finite Element Evaluation of Pervious Concrete Pavement for Roadway Shoulders

Stormwater quantity control is an important issue that needs to be addressed in roadway and ancillary transportation facility design. Pervious concrete has provided an effective solution for storm runoff for parking lots, sidewalks, bike trails, and other applications. It should be readily adaptable for use on roadway shoulders. Being a relatively new material for use in pavement for roadways, there is a lack of knowledge of the strength and behavior of pervious concrete slabs. While standard procedures for rigid pavement design with Portland cement concrete have been recommended, there are fundamental differences with pervious concrete pavement. These include a variation in concrete strength and stiffness through the depth of a slab and differences in the subgrade. Also, the main concern for a shoulder is the need to withstand wheel loadings from encroaching truck traffic. Both the strength of the pervious concrete pavement and the interface with the mainline pavement must be evaluated. Typically, tiebars are used at the interface to connect the shoulder and mainline slabs. The capacity and durability of pervious concrete at the tiebars is unknown, and steel reinforcing may not be an option with pervious systems. While full scale testing of pervious concrete pavement is desirable, a preliminary evaluation can be performed quickly and economically through computer simulation. The Finite Element Method is a proven technique for the evaluation of solids and structures. With this approach, a number of loading scenarios can be applied to various pavement configurations to determine pavement capacity and evaluate the importance of connections with tiebars. The results of these analyses can be used to guide a full-scale testing program and help develop design procedures.