No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Behaviour of Strengthened Timber Beams Using Carbon Fiber Reinforced Polymer
Abstract
Nowadays, construction industry keen on finding the material to replace
concrete and steel. Timber, a renewable construction material has been given more
attention in the research. Moreover, with the existing of Fiber Reinforced Polymer
(FRP) as a strengthening material, timber is potentially to become a popular
construction material. Timber or existing timber structures can be strengthened
using FRP bonding system, a system that been reported to be more effective than
steel bonding system among others due to its lightweight for easy handling during
construction. This research project was conducted in order to investigate the
behavior of timber beams strengthened with Glass Fiber Reinforced Polymer (GFRP)
rods and Carbon Fiber Reinforced Polymer (CFRP) plates. One of the beams was
tested as unstrengthened control beam while five of the beams with same dimension
are strengthened and tested to failure under four point loading. The size of each
beam was 100×200×3000 mm. The behavior of the beams was studied through their
load-deflection characteristics upon loading, timber and FRP strain and mode of
failure. The results showed that the strengthened beams performed better than the
control beam with nominal increase in stiffness and higher ultimate load. Timber
beam strengthened with FRP has an increase in its ultimate load carrying capacity.
The percentage of increase is 6 % to 15 % for beam strengthened with GFRP rods,
and 24 % to 32 % for beam strengthened with CFRP plates. The strengthening of
timber beam with FRP has enhanced the stiffness of the beam. The percentage of
increase is 10 % to 24 % for beam strengthened with GFRP rods, and 7 % to 12 %
for beam strengthened with CFRP plates.Therefore, CFRP plate bonding system is
the most suitable method that can be used in the construction or rehabilitation
process of timber structures.
Keyword – Timber, FRP, Strengthening,
This paper studies the effect management of high temperature on mechanical characteristics of carbon fiber reinforced light weight aggregate concrete. The effect of using high range water reducing agent HRWRA (High range water reducing admixture) with 8% SF (silica fume), as a partial replacement by weight of cement, on the behavior of LWAC (Light weight aggregate concrete) is also studied. Workability, fresh and hardened density, compressive strength, splitting tensile strength and modulus of rupture tests were performed, on specimens of both ages 7 and 28 days. The test results indicated that the inclusion of carbon fiber to the light weight concrete mix did not affect the compressive strength significantly, while the splitting tensile strength and the modulus of rupture were improved significantly. The addition of silica fume improves the compressive, splitting tensile, and modulus of rupture strengths of carbon fiber light weight concrete. The average improvement was about (26.5%, 71% and 73 %) respectively for carbon fiber LWAC containing silica fume. Microstructural properties were studied at ambient temperature and after heating. For each test, the specimens were heated at a rate of 1 C°/min up to different temperatures (150, 450, 600, and 1000°C). In order to ensure a uniform temperature throughout the specimen, the temperature was held constant at the target temperature for one hour before cooling. In addition, the specimen mass was measured before and after heating in order to determine the loss of water during the test. The results allowed us to analyze the degradation of LWAC due to heating. Between 20 and 150 °C, it was associated to an evaporation of free water as well as to an increase in porosity of the tested concretes. Between 150 and 600 °C, in a similar way to the observed evolutions between 20 and 150 °C, due to the departure of bound water, corresponding to a large mass loss. The improvement in microstructure could be attributed to a modification of the bonding properties of the cement paste hydrates (rehydration of the paste due to the migration of water in the pores). Beyond
ResearchGate has not been able to resolve any references for this publication.