Load Transfer Characteristics of Precast Portland Cement Concrete Panels for Airfield Pavement Repairs

Abstract

Portland cement concrete pavement repair technologies using precast portland cement concrete panels have been investigated for decades and recently have gained acceptance and increased use in the United States for highway pavements but have had only limited use for airfields. The recent field testing of a new airfield precast panel repair system indicated that precast panels were suitable for expedient airfield pavement repairs; the panels could withstand between 5,000 and 10,000 passes of C-17 aircraft traffic. Failure of the panels was due to spalling of the transverse doweled joints. The purpose of this study was to determine the load transfer effectiveness, or load transfer efficiencies (LTEs), of the panel repairs. A heavy weight deflectometer was used to collect defection data before, during, and after trafficking to calculate precast panel LTE on the basis of defections (LTEd) or transferred stresses (LT). The LTE values were then evaluated to determine whether current measures of effectiveness were suitable for precast panel repairs. From the results of this investigation, few of the joints provided the current military airfield design assumption of 25% LT, but the majority of the transverse joints exceeded the proposed LTEd threshold of 70% even after failure of the transverse joints. It was recommended that additional field tests be conducted without the use of rapid-setting grout in the joints before recommendations on thresholds were made.