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Value
added sustainable use of recycled and secondary aggregates
in concrete
Ravindra
K. Dhir and Kevin A. Paine
The
paper is based on research projects (including several
demonstration projects) undertaken by the authors,
at the University of Dundee, UK, since 1996, in collaboration
with Government Departments, Local Authorities and
various sectors of the construction industry, to the
tune of several million British sterling pounds, and
actively involving hundreds of stakeholders (major,
medium and small enterprises).1 This research is helping
to create a gradual acceptance of recycled and secondary
aggregates (RSA) for their sustainable use in concrete
and concrete products, in the UK construction industry
( and most likely in other countries as well).2 The
emergence of the 'appropriate use of materials' and
'performance-based standards/specifications' concepts
are considered central to the development of RSA as
a valuable and sustainable resource. An international
'Network RSA in Construction' is being presently established.
.
Investigations
on a distressed reinforced concrete building and its
rehabilitation
B. Dhruva Tara,
Ravande Kishore and D. S. Prakash Rao
Reinforced
concrete structures are prone to deterioration unless
designed, constructed and maintained properly. Some
of the ground floor columns of a 33-year old three
storey reinforced concrete building had developed
severe cracks and spalling. The cracks were noticed
first about a year back, and spread at an alarming
rate. An inspection visit to the building revealed
that the verandah columns had cracked because of seepage
of water from the flowerpots placed between them.
Non-destructive tests using Schmidt rebound hammer
and ultrasonic pulse velocity were performed on the
structure to assess the quality of concrete, and develop
a suitable repair method. Ambient vibration tests
were performed before and after repairs to assess
the effectiveness of repairs. Details of the tests,
repair method and structural performance are described
in this paper.
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