The
use of existing bridge structures are changing with time. The applied loads on
these bridges have become
larger and more frequent in the last decades as the
population and their use have increased. Therefore, strengthening of such
structures becomes a necessity. This paper presents experimental results of
testing four reinforced concrete (RC) beams under monotonic loads. One beam is
kept as a control beam representing the existing structure. The second beam is
strengthened with near surface mounted (NSM) carbon fiber reinforced polymer
(CFRP) rod. The other two beams are strengthened with NSM
prestressed CFRP rod.
Two different levels of prestressing are investigated. The test results show
that using NSM CFRP rod without prestressing enhanced the flexural capacity
(stiffness, yield and ultimate loads) compared to that of the control beam.
Prestressing of NSM rods demonstrates a higher efficiency of using those
expensive materials by achieving the ultimate capacity of the rod at failure.
Beams strengthened with prestressed NSM CFRP rod have enhanced the flexural
performance in terms of flexural stiffness, yield and ultimate loads with
respect to both, the control beam and those strengthened with non-prestressed
NSM CFRP rods.