ASTM C159:06(R2021) pdf free download – Standard Specification for Vitrified Clay Filter Blocks.
in. (0.08 mm) in 16 in. (405 mm) and sufficiently rigid and supported that it will not deflect measurably during the capping operation. Repeat this procedure with the other shellacked surface. Take care that the opposite hearing surfaces so formed will be approximately parallel and perpendicular to the vertical axis of the specimen and that the thickness of the caps will be approximately the same and not exceeding ½ in. (3 mm). Age the caps at least 24 h before testing the specimens.
A1..3 Procedure
A 1.3.1 Test the filter block specimens in a position such that the load is applied in the same direction as in service. Center the specimens under the spherical upper bearing within /I6 in. (1 .6 mm).
A 1.3.2 The testing machine shall conform to the requirements of Practices E4.
A 1.3.3 The upper bearing shall be a spherically seated, hardened metal block firmly attached at the center of the upper head of the machine. The center of the sphere shall lie at the center of the surface of the block in contact with the specimen. The block shall be closely held in its spherical seat, but shall be free to turn in any direction, to allow for specimens whose bearing surfaces are not exactly parallel. The diameter of the bearing block surface shall be at least 5 in. (125 mm). When the bearing area of the spherical bearing block is not suflicicni to cover the area of the specimen, place a steel plate with a thickness equal to at least one third of the distance from the edge of the spherical bearing to the most distant corner of the capped specimen. Use a hardened metal bearing block beneath the specimen to minimize wear of the lower platen of the machine. The bearing block surfaces intended for contact with the specimen should have a hardness not less than 60 HRC (620 HB) and the surfaces shall not depart from plane surfaces by more than 0.001 in. (0.03 mm).
A 1.3.4 Speed of Testing—Apply the load, up to one half of the expected maximum load, at any convenient rate, after which, adjust the controls of the machine so that the remaining load is applied at a uniform rate in not less than I nor more than 2 mm.
A1.4 Calculation and Report
A 1.4.1 Calculate the compressive strength of each specimen as follows.
A2.3.3 Suspend the dried specimens in distilled water; heat to boiling, boil for 1 h, and then cool in the water to ambient temperature. Take care that no fragments are broken from the specimens by physical disturbance during the test. When cool, remove the specimens from the water and drain for not more than 1 min. Then remove the superficial moisture by a damp cloth.
A2.3.4 Weigh the specimens immediately to the nearest 0.5g. Record the weights.