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July,
2011
First
RCT inspection job in Chile
In
the framework of a collaboration agreement with Instituto de
Investigaciones y Ensayos de materiales (IDIEM) of University of Chile to
apply THASA technology in Chile, a service job was carried out in a mine near
the northern city of Iquique. This work entailed the study of anchorage
elements holding rails under several reinforced concrete floors in
Compañía Minera Doña Inés Collahuasi.
April,
2011
Cooperation
agreement with TEIXEIRA DUARTE
THASA
signed a cooperation agreement with TEIXEIRA DUARTE, by which TEIXEIRA
DUARTE assumes the execution of the “field jobs” as part of the full
Reinforced Concrete Tomography services carried out in Portugal, Spain,
Angola, Mozambique and Algeria with exclusivity and in Brazil without
exclusivity. THASA keeps the responsibility for data analysis, tomographic
results and issuing the respective Technical Reports.
June, 2010
Reabilitar Conference 2010, Lisboa, Portugal
THASA participated in
Reabilitar Conference 2010 held in Lisboa, Portugal, on
June 23 to 25. The paper entitled
Desenvolvimento e aplicaçao da tomografia por raios gama na inspecçao de
estruturas de engenharia civil, is coauthored by Mário
Pimentel and Joaquim Figueiras from School of Engineering, University of
Oporto, Department of Civil Engineering, LABEST, Porto and Mario
Mariscotti, Peter Thieberger, Teresita Frigerio and Marcelo Ruffolo of
THASA, and describes the development and application of RCT in civil
engineering structures.
paper
June, 2010
Paper accepted for oral presentation
Edinburgh Conference 2010
THASA participated in
Structural Faults & Repair-2010 Conference held in
Edinburgh, United Kingdom on June 15 to 20. The paper entitled
Gamma-ray inspection of post tensioning cables in a concrete bridge
is coauthored by Mário Pimentel and Joaquim Figueiras from School
of Engineering, University of Oporto, Department of Civil Engineering,
LABEST, Porto and Mario Mariscotti, Peter Thieberger, Teresita Frigerio
and Marcelo Ruffolo of THASA, and presents the application of RCT in the
non-destructive evaluation of condition and internal distribution of post-tensioned girders in N. S. da Guia
bridge, Portugal.
paper
May, 2010
THASA
in Chile
As
member of the commercial mission organized by the Ministry of Foreign
Relations of Argentina, THASA held a number of meetings with businessmen
and entities of Chile.
Much interest was consistently expressed in the application of the
RCT method in connection with the damage suffered during the recent
earthquakes . As a result THASA is currently holding discussions with some
local organizations aimed at providing services taking advantage
of THASA
´s technology in
Chile.
November, 2009
Article published in Concrete International
The article entitled Gamma-Ray Imaging
for Void and Corrosion Assessment was published in
Concrete International, November 2009, Vol. 31 No. 11 pp. 48-53.
The article is Coauthored by Mario Mariscotti of THASA, Frank Jalinoos of
the Federal Highway Administration, Teresita Frigerio, Marcelo Ruffolo and
Peter Thieberger also of THASA, and presents a description of THASA
technology and its utility in the specific case of void and corrosion
detection in post-tensioned girders. The electronic (PDF) version of this
article is available for purchase and download in the magazine web page an
includes additional information of an application case.
paper
March 12, 2009
ASCP Conference in Lisboa
In collaboration with researchers at the University of Oporto a paper has
been submitted to the ASCP’09 – 1st Congress on Bridge Safety and
Conservation ASCP to be held in Lisbon on next July 2 and 3. The
paper entitled Non destructive inspection of pre-stressed ducts and
cables in N.S. da Guia Bridge using gamma-ray tomography is
coauthored by Mário Pimentel and Joaquim Figueiras from School of
Engineering, University of Oporto, Department of Civil Engineering,
LABEST, Porto and Mario Mariscotti of THASA, and presents results of
extended studies carried out in the above mentioned bridge, including
THASA´s Reinforced Concrete Tomography (RCT) technique for inspection of
its pre-stressed girders.
paper
March,
2009
THATIR test successful
THASA´s Real Time Tomograph (THATIR) was successfully applied to detect
steel bars in the center of a 0.55 m (21.6 in) thick concrete sample
(density 2000 Kg/m3,125 lb/ft3) with a low intensity Ir source (16 Ci). It
is known that in conventional industrial radiography which captures data
on photographic or digital plates, Ir sources cannot be used for
inspecting concrete pieces thicker than about 0.3 m (1 ft). Instead of
photographic plates, THATIR uses a highly efficient gamma-ray spectrometer
capable of both detecting very low gamma fluxes and filtering most of the
unwanted scattered radiation. These measurements were prompted by a
customer need for precisely locating pre-stressed ducts in 0.46 m (18 in)
thick girders.
February,
2009
THASA new patent application
All claims in THASA´s new patent PCT International Application have been
fully accepted and held patentable by the US Patent and Trademark Office.
This patent involves 21 claims which cover all aspects of the last
generation gammagraphy tomograph developed by THASA. The system includes
features that provide improved precision for the 3D reconstruction
analysis of steel bars in reinforced concrete as well as better image
quality.
October,
2008
Reinforced Concrete Tomography tested in Portugal
The condition of ducts in pre-stressed girders was studied with gamma rays
in the bridge N. S. da Guia next to the town of Ponte da
Lima in Portugal.
The work was carried out in collaboration with a group from the University
of Oporto lead by Profs. Joaquím Figueiras and Mario Pimentel.
Gammagraphies were obtained in different locations of the bridge floor and
web with the main objective of inspecting the ducts in these locations. A
relatively low intensity Ir source (20 Ci) was used in conjunction with
THASA equipment. A special tool was designed and constructed to position
the source below the bridge floor using previously made holes, thus
avoiding expensive scaffoldings either hanging from the bridge or sitting
on the river bed below the bridge. The result was a successful
non-destructive test, clearly showing the current condition of the ducts.
presentation
September, 2008
ASNT Oakland Conference
THASA presented detailed results of void detection in pre-stressed
girders. These were results obtained earlier at the Zarate Brazo Largo
Bridge in Argentina. The measurements were carried out in one of the large
girders in this bridge with a Ir source. As a result several locations
with defective grouting were identified. The analysis of the most severe
of these cases was discussed in detail in the presentation, showing that,
in addition to the tomographic results (position and size of ducts, cables
and rebars) it is also possible to obtain precise information on the
extension of the voids and corrosion, from these gammagraphies. The talk
resulted in a number of focused and relevant questions from the audience, indicating that the detection of defects in PT girders is an
important cause of current concern worldwide.
paper
June 10,
2008
Edinburgh Conference
The paper presented by THASA was recognized as one of the three best in
the
NDT area. This paper includes results from four different customer
projects: 1) Zarate Brazo Large Bridge (which elicited the invitation to
present a paper at the ASNT Conference in Oakland – see previous item); 2)
Underwater studies carried out in Ushuaia Harbor (Tierra del Fuego); 3)
Detection of termite produced voids in wooden beams in a historical Jesuit
chapel in Córdoba, built in 1660 and declared by UNESCO patrimony of
mankind. This work is the first application of gamma rays to a
hitherto untapped area in the NDT field; and 4) Results from a test done
in the UK in collaboration with Atkins Engineering of Birmingham for the
Highways Agency proved the ability of THASA techniques to detect corrosion
in dowel and scissor bars in hinges of bridge decks.
paper
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