Determination of Strength Characteristics of Construction Timber Strengthened with Carbon and Glass Fibre Composite Using a Destructive Method
Beams strengthened with a composite material consisting of carbon and glass fibre stabilised with two types of adhesives were evaluated. The primary objective was to determine the technical attributes of joints, the maximum bending strength capacity, deflection, and modulus of elasticity. The reinforcement fibres tested were based on carbon and glass fibre. Epoxy and polyurethane adhesives were used for stabilising the fibres on a spruce timber beam. Composite beams glued in both a prestressed and non-prestressed condition were tested and then compared with non-reinforced control beams. A four-point deflection pursuant to EN 408 (1995) was used in the determination of the strength of the load-bearing construction beams based on composites, consisting of a fibre type, adhesive type, and spruce timber. This approach was applied to define the size of the construction beams and process the measurement results. Reinforcing construction beams with fibres applied in a prestressed condition resulted in an increase in the bending strength capacity by 31.6 to 44.4% compared with a non-reinforced solid timber construction beam. These construction elements, strengthened with carbon and glass fibre composites glued with epoxy and polyurethane adhesives, are suitable for applications that require bending resistance perpendiculary to the glued joint direction.
Strengthening and repairing of engineered bamboo-steel epoxy adhesive joints with carbon nanotube on the basis of resin pre-coating method
Combinations of engineered bamboo with wood or even steel substrates have generated increasing attention and research in construction industries around the world. This paper took an experimental study on the bonding properties of engineered bamboo-steel epoxy adhesive joints strengthened and repaired with resin pre-coating (RPC) and carbon nanotube (CNT) surface treatments. The RPC method was applied by pre-coating the diluted resin-acetone solution on the bonding surfaces, while the CNT method was carried out by brushing the CNTs-resin-acetone mixed solution on the bonding surfaces. Test results showed that RPC and CNT surface treatments improved the bonding properties of the adhesive joints. Moreover, compared with the original adhesive joint, as well as the RPC-strengthening or CNT-strengthening joints, the repairing joints had a better performance in terms of bonding strength and energy, especially for the joints repaired with new steel substrates. The reason was that new failure surfaces with decreased cohesive failure and increased adhesive failure happened in the repairing joints, which produced a better bonding property.
Remedial treatment of buildings
Defects in buildings Wood treatment Damp-proofing Masonry treatment Thermal insulation Insect identification Rot identification Diagnosis and measurement of dampness Drying buildings Exposure assessment Thermal properties Glossary Index