ASTM C1824:16(R2021) pdf free download – Standard Test Method for Full Scale Bending Test of Spun Prestressed Concrete Bases for Tapered Steel Lighting Poles.
6.4 Load Cell—The load cell shall have a capacity greater than the load necessary to test the bases to failure. Resolution of the load cell shall be smaller than 10 lb or 1 % of the ultimate load whichever is greater. The load cell shall be attached to the moment arm extension. The load cell and load cell controller shall have current calibration certificate. Calibration shall he performed annually.
6.5 Fixturing (f Text Specimen—The test specimen shall be laterally supported at the two reaction points by rigid fixturing brackets with contact area large enough. at least 20 % of the base circumference by 8 in. (2(X) mm) length. to avoid damage due to stress concentration. The IIxturing brackets shall he lined with elastomeric material (Neoprene or SBR sheet rubber) at least ½ in. (12.5 mm) thick and minimum 70 durometer hardness. Alternatively, seasoned oak at least 4 in. (100 mm) thick can be used as a lining material. The distance between the reaction points (center to center of supports) shall not he less than 5.5 ft (1680 mm) to minimize the shear effects at ground line section. The designed ground line location shall he aligned with the edge of support bracket on the loading side. The bottom end of the test specimen shall extend at least 18 in. from the bottom support bracket
7. Setup Tolerances
7.1 The test specimen centerline, extension arm centerline and loading cable shall be located within 2 in. (50 mm) of theoretical test plane.
7.2 The designed test specimen ground line shall be aligned with the edge of ground line Support bracket within I in. (25 mm).
7.3 The initial load application direction shall be perpendicular to the test specimen centerline within five degrees.
7.4 Test arm adaptor taper and diameter shall be within design tolerances of matching steel pole shaft.
7.5 Test arm adaptor engagement with the test specimen shall be within tolerance range of designed base to pole overlap.
8. Load Measurement
8.1 Load shall he measured by a suitable measuring device placed in series in the pulling line. The recommended method is a calibrated metal tension bar fitted with calibrated electric- type strain gages. that is, load cell, suitably wrapped or housed for protection against shock when the base breaks. This method permits remote reading of loads and minimizes the possibility of personal injury during test. Alternatively, where electric- type strain gaging equipment is not available, load may be measured by a dynarnometer of suitable capacity, graduated in 50 lb (200 N) divisions, maximum increments of I % of the rated capacity. Calibration of the dynamometer shall be checked annually as a minimum at frequent intervals during the tests. A dynamometer is not recommended unless the person reading the data can be protected from inadvertent failure of the pulling line or tackle.
9. Test Specimens
9.1 The test specimens shall be manufactured in accordance with standard manufacturing process in accordance with Spedficat ion C 1804.
9.2 Size and feature dimensions of the test specimens shall be within design tolerances.
9.3 Any damage deemed cosmetic shall he reviewed by a structural engineer prior to testing. Test specimens with damage severe enough to affect structural performance shall not be used for testing.
9.4 Test specimens used for quality control tool for manufacturing process. for design verification, or as a basis for determining statistical bending moment capacity shall be selected randomly and tested at ages between 28 days and 35 days from thcir manufacturing date.
9.5 Bases may also be tested before 28 days or after 35 days for purposes other than specified in 9.4.