31 Dec 94
A-5. ETL Recommendations
What are the basic principles?
How do I do a thermal study?
a. Future guidance.
(3) It is recommended that future documentation
(1) Future guidance concerning mass concrete
address these issues. The document should address
should address whether performing a NISA is manda-
the basic issues of the goals and desired objectives
tory. Current guidance is unclear i.e., a reader can
when performing thermal studies and supplemented
either assume that a NISA is mandatory (ETL 1110-
with more specific information, for all levels of
2-324 paragraph 7a) or that the need for such an
investigation is subject to consideration (ETL 1110-2-
324 paragraph 7b). It should be noted that a new
(4) Guidance in the ETL references acceptable
ETL has been published, that incorporates updated
bandwidths to be applied to the mechanical properties
information based on NISA's that have been per-
of the concrete for estimated data. There are several
formed by WES that may address these issues. The
ways to generate reasonable estimates of this data at
considerations for when to implement a NISA versus
the time of the analysis. Further guidance, that would
other less comprehensive analyses need to be devel-
be beneficial, should reference other sources that
oped and included in any comprehensive policy
contain the methodologies to estimate the data.
(5) We concur with the recommendation of the
(2) Certain basic questions must be addressed
ETL that the full intended benefit of a NISA requires
prior to embarking on a NISA. These include:
the combined efforts of the structural designer, mate-
rials engineer, cost engineer, and the geotechnical
Why do a thermal study?
Is a thermal study appropriate for this struc-
ture? If so, what level of analysis is