ASTM C497-2018 pdf free download

ASTM C497-2018 pdf free download.Standard Test Methods for Concrete Pipe, Manhole Sections, or Tile
4. External Load Crushing Strength Test by the Three- Edge Bearing Test Method
4.1 Summary ofTest Method—The test specimen is tested in a machine designed to apply a crushing force upon the specimen in a plane through the vertical axis extending along the length of the specimen.4.2 Significance and Use—The crushing test shall be either a quality control test performed to establish that the finished, shippable pipe has sufficient strength to withstand the crushing loads stated in the specifications or a proof of design test performed to prove the adequacy of design. 4.3 Apparatus: 4.3.1 The testing machine shall be of any type of sufficient capacity and shall be capable of providing the rate of loading prescribed in 4.5.3. 4.3.2 The testing machine shall be substantial and rigid throughout, so that the distribution of the load will not be affected appreciably by the deformation or yielding ofany part. 4.3.3 The three-edge-bearing method of loading shall be used. The test specimen shall be supported on a lower bearing of two parallel longitudinal strips and the load applied through an upper bearing (Figs. 1-4). At the option ofthe manufacturer, either or both the lower bearing and the upper bearing shall extend the full length or any portion of the length of the specimen. Fig. 5 4.3.4 The lower bearings shall consist of wood or hard rubber strips. Wooden strips shall be straight, have a cross section ofnot less than 2 in. in width and not less than 1 in. nor more than 1 1 ⁄ 2 in. in height and shall have the top inside corners rounded to a radius of 1 ⁄ 2 in. Hard rubber strips shall have a durometer hardness of not less than 45 nor more than 60. They shall be rectangular in cross section, having a width of not less than 2 in., a thickness of not less than 1 in. nor more than 1 1 ⁄ 2 in., and shall have the top inside corner rounded to a radius of 1 ⁄ 2 in.4.3.5 The lower bearing strips shall be fastened to a wooden or steel beam or directly to a concrete base, any of which shall provide sufficient rigidity so that deflection is not greater than 1 ⁄ 720 ofthe specimen length when the maximum load is applied. The rigid base shall be at least 6 in. wide. The interior vertical sides of the strips shall be parallel and spaced a distance apart of not more than 1 in./ft of specimen diameter, but in no case less than 1 in. The bearing faces of the lower strips shall not vary from a straight line vertically or horizontally by more than 1 ⁄ 32 in./ft of length under no load. 4.3.6 The upper bearing shall be a rigid wood beam with or without an attached hard rubber strip. The wood shall be sound, free of knots, and straight and true from end to end. It shall be fastened to a steel or wood-faced steel beam of such dimen- sions that deflections under maximum load will not be greater than 1 ⁄ 720 of the specimen length. The bearing face of the upper bearing shall not deviate from a straight line by more than 1 ⁄ 32 in. ⁄ft of length. When a hard rubber strip is used on the bearing face it shall have a durometer hardness of not less than 45 nor more than 60, and shall have a width of not less than 2 in. and a thickness of not less than 1 in. nor more than 1 1 ⁄ 2 in. and shall be secured to a wood beam meeting the above requirements. 4.3.7 If mutually agreed upon by the manufacturer and the owner prior to the test, before the specimen is placed, a fillet of plaster of paris not exceeding 1 in. in thickness shall be cast on the surface of the upper and lower bearings. The width of the fillet cap, upper or lower, shall be not more than 1 in./ft of the specimen diameter, but in no case less than 1 in.