RETROFIT LOAD TRANSFER: SPECIAL DEMONSTRATION PROJECT SP-204

The objective of this Special Demonstration Project SP-204 was to promote the development by industry of equipment to make retrofit load transfer with smooth, round dowel bars a cost-effective maintenance and rehabilitation technique. This report covers a 4-year period from the initial development of this proposal through 1997 in which this technique (and the equipment developed) was used on regular construction or maintenance projects in the States of Washington, Kansas, South Dakota, Minnesota, North Dakota, Michigan, New Jersey, and West Virginia. It has been used routinely in Puerto Rico since 1983 (slots sawed individually). The technique involves the construction of slots (at least three in one wheelpath) by diamond sawing (Concrete Textures, Inc.; Cushion Cut; and Magnum Diamond and Machinery, Inc.) or by carbide milling (Keystone Engineering & Manufacturing Corporation). The slots are cleaned, 350-mm dowels on chairs are set in place, and the patching material (using fast-set materials) is placed. The surface is diamond or carbide ground and the joint and/or cracks are sawed and resealed. Load transfer has been restored at undoweled joints in jointed plain concrete pavement (JPCP) and at cracks in JPCP and at poorly performing doweled joints or working cracks in jointed reinforced concrete pavement. Background and project development information is included in appendices A and B. Detailed design, construction, and/or maintenance guidelines are provided in appendix C. Georgia, Puerto Rico, Indiana, Washington State, Kansas, South Dakota, and Michigan procedures and/or specifications are provided in appendices D-I and O. A videotape of the various procedures from Washington State, Kansas, and Indiana DOTs is also available from FHWA (total time - 52 minutes).