It is generally recognized that fibrous composite have a higher strength-to-weight ratio than conventional materials. By replacing steel with fibrous composites, the deficiencies, such as electrochemical deterioration can be eliminated. Other benefits include high strength, large energy absorption and enhanced ductility....[ Read more ]

It is generally recognized that fibrous composite have a higher strength-to-weight ratio than conventional materials. By replacing steel with fibrous composites, the deficiencies, such as electrochemical deterioration can be eliminated. Other benefits include high strength, large energy absorption and enhanced ductility.

The thesis first presents the preliminary results of a study on a composite tube reinforced concrete column. In such a column, the plain concrete was cast inside the prefabricated composite tube with no steel reinforcement. Two circular conventional reinforced concrete columns, as reference specimens, and three glass fiber tube reinforced concrete columns have been tested under pseudo static loading. The 3-dimension strain and horizontal displacement are measured by rosette strain gauges and LVDTs, respectively, whereas the micro-crack and failure processes are monitored by means of acoustic emission (AE). The objective of this test is to assess the mechanical behavior (strength, ductility) of concrete columns reinforced with a glass fiber tube. The composite tube reinforced concrete column shows greatly enhanced seismic resistance as compared to the conventional reinforced column. Hence, there is great potential in the future for such a structure being applied in seismic regions.

The second part of the thesis deals with a feasibility study on new type of beam-column joint of fiber strand reinforced concrete column. Such a column was made by casting concrete into a carbon fiber strand reinforced PVC tube. The compressive behavior of a PVC tube-carbon fiber reinforced concrete column had been studied. In the present study, 10 PVC tube columns were used to build a joint in a concrete beam. A joint element was formed by filament winding of glass fiber strands, and looked like a rib with dimensions of 10 x 10 mm, 2 or 3 ribs per joint. A compression test was carried out on the specimens, aiming at studying the mechanical properties and structural behavior of the joint. The strain and relative displacement were measured by strain gauges and LVDTs, respectively. The experimental results showed that rib type of joint had good load carrying capacity and promising potential in practice.