AASHTO T 253:02(2020) Standard Method ofTest for Coated Dowel Bars.
1.1. These methods are designed to test the qualifications of the organic coating of corrosion-resistant dowel bars to withstand the effects of weathering, deicing chemicals, and the abrading and loading stresses experienced in field joints.
1.2. The units of measure to be used shall be either SI units or inch-pound units (shown in parentheses in this standard) depending on the units used in the applicable material specification.
1.3. The values stated in SI units are to be regarded as the standard.
3.4. Universal test machine capable of operating accurately in the 0- to 45-kN (1 OMOO lbf) ranges and capable of controlled stress and strain rate loading.
3.5. Suitable hold-down devices for positioning and holding the casting in place without rotation during the flex ure tests.
3.6. Freeze thaw equipment of sufficient capacity to handle the pullout and corrosion abrasion test specimens.
3.7. Suflicient quantities of chemical to maintain solution for corrosion tests.
4.1. The coated dowels for deflection tests may be in support baskets or loose. The coated dowels for the remainder of tests shall be loose.
4.2. Type A—coated dowels shall be cast without additional coating of any kind. Type B—coated dowels shall be covered before casting with the debonding agent specified by the coating manufacturer.
4.3. The prepared dowels shall be cast in the appropriate molds specified for the various tests.
5.1. Six dowels with basket assemblies, if any, will be utilized in three load-deflection tests. The test will be conducted in accordance with the following procedures:
5.2. Two dowels with basket assemblies, or without basket assemblies in case of loose dowels, shall be cast into each concrete test specimen in a manner to simulate two 305-mm- (12-in.) long highway contraction joints. (See Figure 1.) The contraction joints are tbrrned by dividing the mold into three sections with two-piece plates 9.5 mm (3/s in.) thick. After the mold has been filled, the concrete shall be consolidated by vibration.
5.3. The concrete test specimens shall be made and cured in accordance with R 39. The specimens shall be removed from the molds after a 24-h curing period and shall be further moist-cured for a total of 14 days.
5.4. On completion of curing, the simulated joint shall be placed in a testing machine and loaded as illustrated in Figure 1. The end sections will be provided with suitable hold-down devices to prevent rotation. The load shall be applied at the rate of 8.9 kN/min (2000 lbf/min) until a load of 17.8 kN (4000 lbf) is obtained. The relative deflection between the loaded center section and the supported stationary ends will be measured under the I 7.8-kN (4000-lbf) maximum load. Record maximum relative deflection under load.AASHTO T 253 pdf download.