Concrete slab analyses with field-assigned non-uniform support conditions

Abstract

Intelligent compaction (IC) technologies have been used to locate and identify areas of soft, weak or non-uniform subgrade support, which can be linked to pavement performance to set realistic limits on allowable non-uniformity as identified by IC. Based on field data, finite element analyses were performed to investigate the impact of non-uniformities on concrete slab tensile stresses. Non-uniform support cases were modelled by deterministically and randomly assigning field-correlated moduli of subgrade reaction (k-values) to specific spatial areas in the foundation layer. Stresses depended on the size of the non-uniform area, the stiffness change between adjacent non-uniform areas, load location and configuration, and temperature differential. Cases with randomly assigned k-values showed as much as a 39% increase in peak slab tensile stresses relative to a uniform support condition, which could lead to premature slab failures. The ability of IC to locate foundation non-uniformities could increase the reliability of concrete pavements.

Keywords:

• non-uniform support
• finite element analysis
• intelligent compaction
• rigid pavement
• field data

Acknowledgements

The authors particularly thank Professor David J. White and Dr Pavana Vennapusa at Iowa State University for collaboration. In addition, the authors would like to acknowledge Applied Research Associates for the use of the ISLAB2000 software.

Notes

^1. Email: [email protected]

^2. Email: [email protected]

^3. Email: [email protected]

Additional information

Funding

The Federal Highway Administration and Iowa State University funded this project as part of [grant number DTFH61-06-H-00011] Work Plan 18.