Engineering properties of brittle repair materials.

PDFTech ReportFHWA/LA-92/25489-2CConcrete pavementsBiaxial stressEvaluationPavement maintenancePatchingLouisianaLouisiana State University, Baton RougeVoyiadjis, George Z.Channakeshava, C.Abu-Lebdeh, T. M.Barzegar, F.Louisiana State University (Baton Rouge, La.). Dept. of Civil and Environmental EngineeringLouisiana Transportation Research CenterUnited States. Federal Highway AdministrationUS Transportation CollectionMost codes of practice prescribe procedures for selecting patch configuration and materials based on tests devised for evaluating new pavement materials. This study is aimed at examining the special consideration to be given to such evaluation procedures and to suggest improved procedures for brittle repair materials, based on additional tests and computer analysis. The first part of the present investigation covers the experimental study, in which three different repair materials, namely plain concrete, steel fiber concrete, and rapid patch material (Duracel cement), are investigated. Tests are conducted on two different patch configurations (transition and rectangular) and three different patch depths (2, 4 and 6 in.). The experimental procedure to evaluate a brittle repair material consists of four tests, namely, uniaxial strength test, biaxial strength test, bond strength tests, and shear test of a repaired pavement joint. As a result of the experimental study, it is concluded that the proposed biaxial testing set-up has been shown to provide a better understanding by which the strength and behavior of brittle repair materials can be fully investigated. It is observed that the strength of the repair material under combined tension and compression is lower than under uniaxial compression, and the strength decreases as the applied tensile stress is increased. In the second part of this study, a mechanistic patched pavement analysis program is developed to assist in the evaluation of patching procedures and materials. Such a program can be used to develop curves which aid in the selection process. It can also be used for a case by case analysis for specific problems. This program can analyze both intact and patched concrete pavements considering different loading and support conditions, material properties, patch configurations, and depths. In this study, for the first time a complete distress simulation capability has been built into a three dimensional analysis program and it is expected that analysis using this program would enable better understanding of pavement behavior, which can lead to proper guidelines for evaluation of different materials and repair procedures in rehabilitating rigid-jointed pavements. This report is presented in two volumes. Volume II contains the Appendices. A separate Summary Report is issued as report number FHWA/LA-92/253