ASTM C1824-16(2021)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1824 − 16 (Reapproved 2021)
Standard Test Method for
Full Scale Bending Test of Spun Prestressed Concrete
Bases for Tapered Steel Lighting Poles
This standard is issued under the fixed designation C1824; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope than the sum of induced compression plus the tensile strength
of the concrete resulting in tensile cracks on the tension face of
1.1 This test method covers determination of ultimate bend-
the base.
ing moment capacity and cracking moment capacity of con-
3.1.2 cylindrical section—lower portion of base designed to
crete bases used as foundations for tapered steel lighting poles
be buried in concrete backfill below ground line.
in accordance to Specification C1804.
3.1.3 ground line—the distance from the butt end of the base
1.2 The values stated in inch-pound units are to be regarded
to the point where theoretical embedment in the foundation is
as standard. The values given in parentheses are mathematical
specified (theoretical buried depth).
conversions to SI units that are provided for information only
and are not considered standard.
3.1.4 second crack (re-cracking) load—the load at which a
previously formed crack will reopen.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.1.5 spun base—a base in which the concrete is distributed
responsibility of the user of this standard to establish appro-
and compacted through centrifugal force.
priate safety, health, and environmental practices and deter-
3.1.6 tapered section—upper portion of base, which has a
mine the applicability of regulatory limitations prior to use.
taper designed to match overlapping steel pole taper.
1.4 This international standard was developed in accor-
3.1.7 ultimate load—maximum test load the base will carry
dance with internationally recognized principles on standard-
in the specified direction before the steel or concrete will reach
ization established in the Decision on Principles for the
its limiting state.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
4. Summary of Test Method
Barriers to Trade (TBT) Committee.
4.1 This test consists of applying transverse loads at a
predetermined distance to simulate bending moments induced
2. Referenced Documents
by wind forces exerted on the spun concrete base. The base is
2.1 ASTM Standards:
tested in a horizontal orientation. The concrete base specimen
C39/C39M Test Method for Compressive Strength of Cylin-
is laterally supported at two locations: at the ground line and
drical Concrete Specimens
near the bottom end of the base. The bending load is applied
C192/C192M Practice for Making and Curing Concrete Test
through a steel test arm consisting of a matching taper steel
Specimens in the Laboratory
adaptor with appropriate extension, which is of sufficient
C1804 Specification for Spun Cast Prestressed Concrete
length to deem shear effects negligible. Bending loads are
Bases for Tapered Steel Lighting Poles
applied gradually at a predetermined loading sequence. The
test bending moment is determined by multiplying the moment
3. Terminology
arm measured from the simulated ground line to the load
3.1 Definitions:
application point multiplied by the applied load value. Due to
3.1.1 cracking load—a load which creates a bending mo- the relatively short height of these bases extending above
ment of enough magnitude to produce a tensile stress greater
ground line in comparison to the entire structure height,
obtaining deflection data is not required.
5. Significance and Use
This test method is under the jurisdiction ofASTM Committee C27 on Precast
Concrete Products and is the direct responsibility of Subcommittee C27.20 on
5.1 This test method is intended to provide the user with
Architectural and Structural Products.
acceptable apparatus requirements and a prescribed procedure
Current edition approved Jan. 1, 2021. Published January 2021. Originally
to determine the bending moment capacity of spun pre-stressed
approved in 2016. Last previous edition approved in 2016 as C1824 – 16.DOI:
10.1520/C1824–16R21. concrete bases for use with tapered steel poles.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1824 − 16 (2021)
5.2 The results of this test method are used as a basis for 6.4 Load Cell—The load cell shall have a capacity greater
verification of calculated bending moment capacity, quality than the load necessary to test the bases to failure. Resolution
control tool for manufacturing process and as a basis for of the load cell shall be smaller than 10 lb or 1 % of the
determining statistical bending moment capacity. ultimate load whichever is greater. The load cell shall be
attached to the moment arm extension. The load cell and load
5.3 This test method shall not be used for full length
cell controller shall have current calibration certificate. Cali-
prestressed concrete, steel, or composite poles.
bration shall be performed annually.
6. Apparatus
6.5 Fixturing of Test Specimen—The test specimen shall be
laterally supported at the two reaction points by rigid fixturing
6.1 General Requirements—The test area, fixtures and adap-
brackets with contact area large enough, at least 20 % of the
tors shall be sized to accommodate the largest test specimens
base circumference by 8 in. (200 mm) length, to avoid damage
with adequate margin to include upper tolerances of test
specimens. The general layout shall allow for application of due to stress concentration. The fixturing brackets shall be
lined with elastomeric material (Neoprene or SBR sheet
transverse loads in direction perpendicular to the centerline of
test specimen (see Fig. 1). rubber) at least ⁄2 in. (12.5 mm) thick and minimum 70
durometer hardness. Alternatively, seasoned oak at least 4 in.
6.2 Loading Apparatus—The loading apparatus consists of
(100 mm) thick can be used as a lining material. The distance
a winch and a steel cable through which the load is applied to
between the reaction points (center to center of supports) shall
the test arm. The winch machine shall be capable of applying
not be less than 5.5 ft (1680 mm) to minimize the shear effects
loads that are required to test the bases to failure. The loading
at ground line section. The designed ground line location shall
apparatus shall be capable of applying the required loading
be aligned with the edge of support bracket on the loading side.
sequence in continuous manner. The loading apparatus shall be
The bottom end of the test specimen shall extend at least 18 in.
capable of starting and stopping force application under load,
from the bottom support bracket
as well as, it shall be capable of maintaining a static load at any
point during the test sequence.
7. Setup Tolerances
6.3 Test Arm—The test arm shall consist of tapered steel
7.1 The test specimen centerline, extension arm centerline
adaptor and extension. The inside diameter and taper of the
and loading cable shall be located within 2 in. (50 mm) of
adaptor shall match the outside diameter and taper of the test
specimen. The extension shall be long enough to allow for a theoretical test plane.
load application point with a moment arm that will ensure
...