Ultrasonic Evaluation Methods Applicable to Polymer Concrete Composites.
Ultrasonic Evaluation Methods Applicable to Polymer
Concrete Composites.
(3173 K)
Garbacz, A.; Garboczi, E. J.
NISTIR 6975; 73 p. April 2003.
Order number: PB2003-104546
Keywords:
concretes; polymer composites; repair materials;
material design; ultrasonic methods; material science;
velocity method; ultrasonic echo method; industrial
floors
Abstract:
Polymer composites (PC) appear as useful materials for
repair and protection of building structures, as well as
for manufacturing pre-cast elements. In the case of
pre-cast elements as well as repair materials, the
usefulness and durability of polymer composites depend
on the selection of the material composition for
obtaining the composite with controllable properties.
This task is a material design and optimization
procedure. For repairs and protective coatings, the main
problem is good bonding between PC composites and
concrete substrate, including the effect of time. In
both cases there is a need for quality control
(verification tests) and diagnosis tests during
structural service as well. This is available using
destructive or semi-destructive tests. Such a way of
testing, however, is expensive and of limited usability
due to its destructive character. Therefore, the
development of nondestructive assessment methods for
polymer composites is an important need. Ultrasonic
methods are among the most common nondestructive
techniques used in material science and industry.
Ultrasonic methods are well-known and standardized
towards the traditional building materials, like:
metals, cement, concrete, rocks. In the case of polymer
concrete composites, ultrasonic methods are at the
introductory stage. The obtained results of the project
confirmed the usefulness of ultrasonic methods for
nondestructive evaluation of polymer concrete composites
in various applications. The pulse velocity method can
be used for evaluation of the properties and homogeneity
of the pre-case elements made from polymer concrete as
well as for evaluation of adhesion in the multi-layer
PC-CC systems (adhesion mapping). The ultrasonic echo
method can be used as a complementary method for
nondestructive estimation of PC layer thickness. Results
of the project are presented in this report. The
appendix contains a list of the eight publications that
were presented during international and domestic
conferences and published in proceedings and journals.
The project's results are in general accord with
worldwide scientific and engineering activities in
nondestructive quality control of repair, e.g., Guide
for Evaluation of Concrete Structures Prior to
Rehabilitations, ACI 364.1R-94, 2001; the Family of
European Standards 1504; Products and Systems for the
Protection and Repair of Concrete Structure; and
Activities of RILEM Technical Committees: TC-151
"Adhesion Technology in Concrete Engineering - Physical
and Chemical Aspects" and TC-184 IFE "Industrial Floors
for Withstanding Harsh Environmental Attacks, Including
Repair and Maintenance."
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899