DYNAFLECT/BENKELMAN BEAM CORRELATION. FINAL REPORT

With recent rehabilitation work progressing on Colorado's Interstate Portland Cement Concrete Pavements (PCCP), the Department of Highways found that many new PCCP condition surveys would be required. An important part of the condition survey is the deflection measurements at joints, midslab, and cracks of the plain jointed PCCP. This study looked at primarily the joints and cracks in the pavement for its evaluation. Deflections are presently measured with a department-owned Dynaflect or a Benkelman Beam. The beam is cumbersome, making it slow and costly to use. As a result, a project was initiated to correlate results from the faster Dynaflect to the results of the labor-intensive Benkelman Beam. This report describes the procedures and results of the Benkelman Beam/Dynaflect correlation. Based on the data collected for this study, there is no conclusive evidence that a valid correlation exists between the two devices. If the Dynaflect or a Benkelman Beam is to be used for deflection evaluation of rigid pavements, equipment operating recommendations within this report should be strongly considered.