Section 27-596
§ 27-596 General. The structural design of a member or assembly shall
be deemed to be adequate if the design computations demonstrate
conformance with the applicable standards noted in articles four through
twelve of this subchapter. Where, because of practical difficulties,
such computations cannot be executed, the structural design may be
deemed adequate if the member or assembly is subjected to, and
satisfactorily performs under, load tests in accordance with the
provisions of subdivision (a) of section 27-599 of this article. Where
there is a question as to the adequacy of a completed or partly
completed construction, the provisions of sections 27-597, 27-598, and
subdivision (b) of section 27-599 of this article shall apply.
Section 27-597
§ 27-597 Questionable construction. If, upon inspection, it is found
that a construction or any part thereof, as built, shows open cracks,
spallings, or other signs of distress; or should inspection records show
more significant deficiency of construction; or should laboratory tests
on concrete or other materials that have been incorporated into the work
indicate deficiency of strength; or should there be a reasonable doubt
as to the strength, stability, or adequacy of the construction or any
part thereof, such construction may be checked to verify the adequacy
thereof either by computation, or by core or load tests conducted in
accordance with the provisions of section 27-598 or subdivision (b) of
section 27-599 of this article or by any combination of these means.
Should the adequacy of construction not be verified within a reasonable
time, such construction shall be rejected and shall be demolished or
reinforced or rebuilt to be made safe in conformance with the
requirements of this code. In the event of a disagreement, the final
decision as to the acceptance of the work shall be made by the
commissioner. All such tests shall be made without expense to the city.
Section 27-598
§ 27-598 Core tests of concrete construction. The adequacy of the
concrete in a building may be ascertained by the recovery and testing of
cores. Cores shall be taken and tested in accordance with the procedure
described in reference standard RS 10-16. In lieu thereof, cores
cast-in-place and originally cured with the parent concrete, or other
device acceptable to the architect or engineer designated for controlled
inspection and which will produce test specimens simulating the
condition of the concrete in place including the size and proportions
specified for core specimens may be utilized to demonstrate the adequacy
of the concrete in place. The compressive strength so determined shall
meet the requirements for strength tests as described in reference
standard RS 10-3.
Section 27-599
§ 27-599 Load tests. (a) Prequalifying load tests. The provisions of
this section shall apply only to load tests made for the purpose of
establishing the structural adequacy of members or assemblies before
such members or assemblies are incorporated into the work. Load tests
for the purpose of establishing the strength of an element or assembly,
in place, after construction, shall conform to the requirements of
subdivision (b) of this section.
(1) TEST SPECIMENS. The test specimens shall be a true representation
of the units or assemblies to be used in the work and, unless sufficient
tests are conducted on differing specimens to interpolate the
performance of members of varying characteristics, test specimens shall
be substantially identical with the units or assemblies to be used in
service. Particular attention shall be given to matching the type and
grade of material and, in the case of concrete, the mix, age, curing,
and other pertinent variables.
(2) SUPPORT CONDITIONS AND INTERACTION. Load tests shall be performed
in such a manner that the supports for the members or assemblies being
tested will simulate the conditions of support in the building, except
that conditions of partial fixity may be approximated by condition of
full or zero restraint, whichever produces a more severe stress
condition in the member being tested. The test conditions shall be such
as to obviate all interaction of fills, finishes, partitions, supports,
or members whose interaction normally would be neglected in design.
Where continuous, multiple, intersecting, or connected members are used
in the test, all interacting members shall be simultaneously and fully
loaded and additional tests shall be performed under the partial loading
conditions specified in subchapter nine of this chapter. Test specimens
shall not be unloaded and reloaded or subjected to cyclical loading,
except as specifically required by the provisions of this code and
except that the adding of increments of additional load to a member
already under load and the application of the test load as described in
subparagraph b of paragraph three of this subdivision following removal
of the test load described in subparagraph a of paragraph three of this
subdivision will be permitted.
(3) STRENGTH REQUIREMENTS. The member or assembly, supported as
described in paragraph two of this subdivision, shall be capable of
supporting:
a. Without visible damage (other than hairline cracks) its own weight
plus a test load equal to one hundred fifty per cent of the design live
load plus one hundred fifty per cent of any dead load that will be added
at the site; and
b. Without collapse, its own weight plus a test load equal to fifty
per cent of its own weight plus two hundred fifty per cent of the design
live load plus two hundred fifty per cent of any dead load that will be
added at the site. The latter loading shall remain in place for a
minimum period of one week. All loading conditions described in
subchapter nine of this chapter shall be considered. The design live
load shall be the nominal value reduced for contributory area as
described in subchapter nine. Except as permitted under paragraph five
of this subdivision, units to be tested shall be full size. Load bearing
wall and partition assemblies shall be tested both with and without
window and door framing where such framing will be included in the final
assemblies.
Exception. If the load tests are conducted and the results promulgated
in a manner that will permit clear differentiation between the dead and
live load components added at the site, then the capacity of the member
or assembly without visible damage other than hairline cracks as
determined under load test condition in subparagraph a of paragraph
three of this subdivision, may be reduced to the weight of the member,
plus any dead load that will be added at the site, plus one hundred
fifty per cent of the design live load; and the capacity of the member
or assembly to resist collapse as determined under load test condition
in subparagraph b of paragraph three of this subdivision may be reduced
to one hundred fifty per cent of the weight of the member, plus one
hundred fifty per cent of any dead load that will be added at the site,
plus two hundred fifty per cent of the design live load.
(4) DEFLECTION REQUIREMENT. With the member or assembly supported as
described in paragraph two of this subdivision, and after loading as
required by the provisions of subparagraph a of paragraph three of this
subdivision and the removal of said load, the percentage of recovery of
the deflection caused by the superimposed load shall be at least
seventy-five per cent. The deflection under the design live load shall
not exceed that permitted in this subchapter.
(5) MODEL TESTS. Tests on models less than full size may be used to
determine the relative intensity, direction, and distribution of
stresses and applied loads, but shall not be considered as a proper
method for evaluating stresses in, nor the strength of, individual
members unless approved by the commissioner for this purpose. Where
model analysis is proposed as a means of establishing the structural
design, the following conditions shall be met:
a. Analysis shall be made by a firm or a corporation satisfactory to
the commissioner.
b. The similitude, scaling, and validity of the analysis shall be
attested to by an officer or principal of the firm or corporation making
the analysis.
c. A report on the analysis shall be submitted showing test set-ups,
equipment, and readings.
(b) Load tests of completed construction. The provisions of this
subdivision shall apply to any type of construction where the
appropriate reference standard does not provide for load test of
completed construction and the construction is questionable. When the
appropriate reference standard provides for such load testing, the
provisions of reference standard shall be used.
(1) Strength. The construction shall be loaded in two stages:
(a) With all dead load to which it will be subjected in service plus a
superimposed load equal to the design live load reduced as described in
subchapter nine of this chapter; and
(b) With a total load, including its own weight, equal to one hundred
fifty per cent of the total dead load to be supported in service plus
one hundred eighty per cent of the design live load, reduced for
contributory area as described in subchapter nine of this chapter, which
load shall remain in place for a minimum period of twenty-four hours.
(2) Deflection requirement. Under the first stage loading, the
deflection shall not exceed that permitted in the applicable reference
standard. The residual deflection after removal of the second stage
loading shall not exceed twenty-five per cent of the calculated elastic
deflection under the superimposed test load. The structure, after
recovery of the deflection shall not show any evidence of serious
distress.
(3) Interaction. The load area shall extend to include the loading of
all framing and elements that contribute to the strength of the element
or elements under test, by way of interaction.
(4) Lateral loads. Where the elements in question must resist lateral
loads in service, such loads shall be simulated in the tests. In such
case, the magnitude of the applied live load and lateral load components
of the test load may be adjusted as described in section 27-594 of
article two of this subchapter, provided that the stress condition under
the load increments described in paragraph one of this subdivision is
not more critical.
(5) Reloading. Unloading and reloading or cyclical loading of test
areas will not be permitted, except for the addition of increments of
additional load to a member already under load.
To the extent possible under law, Friends of Devin Balkind for Public Advocate has waived all copyright and related or neighboring rights to New York City Administrative Code. This work is published from: United States.
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