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.
1.1 This test method covers determination of ultimate bending moment capacity and cracking moment capacity of concrete bases used as foundations for tapered steel lighting poles in accordance to Specification C1804.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
3. 1 .2 cylindrical section—lower portion of base designed to be buried in concrete backfill below ground line.
3.1.3 ground line—the distance from the butt end of the base to the point where theoretical embedment in the foundation is specified (theoretical buried depth).
3. 1 .4 second crack (re-cracking) load—the load at which a previously formed crack will reopen.
3.1.5 spun base—a base in which the concrete is distributed and compacted through centrifugal force.
3.1.6 tapered section—upper portion of base, which has a taper designed to match overlapping steel pole taper.
3. 1 .7 ultimate load—maximum test load the base will carry in the specified direction before the steel or concrete will reach its limiting state.
4. Summary of Test Method
4. 1 This test consists of applying transverse loads at a predetermined distance to si mu late bending moments induced by wind forces exerted on the spun concrete base. The base is tested in a horizontal orientation. The concrete base specimen is laterally supported at two locations: at the ground line and near the bottom end of the base. The bending load is applied through a steel test arm consisting of a matching taper steel adaptor with appropriate extension, which is of sullicient length to deem shear effects negligible. Bending loads are applied gradually at a predetermined loading sequence. The test bending moment is determined by multiplying the moment arm measured from the simulated ground line to the load application point multiplied by the applied load value. Due to the relatively short height of these bases extending above ground line in comparison to the entire structure height, obtaining deflection data is not required.
5. Significance and Use
5.1 This test method is intended to provide the user with acceptable apparatus requirements and a prescribed procedure to determine the bending moment capacity of spun pre-stressed concrete bases for use with tapered steel poles.ASTM C1824 pdf download.