a field program of strain and deflection measurements was conducted by the construction technology laboratories (ctl) for the iowa department of transportation. The objective of the field measurement program was to obtain information on bonded concrete resurfaced pavements that can be used as a data base for verifying bonded resurfacing thickness design procedures. Data gathered during the investigation included a visual condition survey, engineering properties of theoriginal and resurfacing concrete, load related strain and deflection measurements, and temperature-related curl (deflection) measurements. Field load testing was conducted by ctl at five sites in iowa during april 1986. This report presents the results of field testing, analysis of results, and recommendations to incorporate study results in iowa design procedures for bonded concrete overlays. Results of the investigation indicate that the four overlaid pavement sections evaluated as part of the reported study are performing as monolithic pavements with high interface shear strength at the interface. The strength of the existing pavement at all of the four overlaid testsections was high. In addition, cores obtained from sections 4 and 5 did not indicate d-cracking related damage in the overlay concrete. Coparison of the condition surveys for section 1 (non-overlaid jrcp) and section 2 (overlaid jrcp) indicate that all cracking in the existing pavement is not reflected through the overlay and that the cracks that did reflect through have remained tightly closed. Similarly, the condition survey of sections 4 and 5 indicate that cracks reflected through the overlay continue to remain tightly closed even after almost seven years of service. The field investigation conducted by ctl verifies that for properly constructed bonded overlays, pavement strengthening is achieved and that the overlaid pavement behaves monolithically as a full-depth concrete pavement. This paper appears in transportation research record no. 1196, Pavement evaluationand rehabilitation.
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