Developments and advanced applications of concrete-filled steel tubular (CFST) structures: Members

Natural fibers today are a popular choice for applications in composite manufacturing. Based on the sustainability benefits, biofibers such as plant fibers are replacing synthetic fibers in composites. These fibers are used to manufacture several biocomposites. The chemical composition and properties of each of the fibers changes, which demands the detailed comparison of these fibers. The reinforcement potential of natural fibers and their properties have been described in numerous papers. Today, high performance biocomposites are produced from several years of research. Plant fibers, particularly bast and leaf, find applications in automotive industries. While most of the other fibers are explored in lab scales they have not yet found large-scale commercial applications. It is necessary to also consider other fibers such as ones made from seed (coir) and animals (chicken feather) as they are secondary or made from waste products. Few plant fibers such as bast fibers are often reviewed briefly but other p...

A Review of Natural Fibers Used in Biocomposites: Plant, Animal and Regenerated Cellulose Fibers

Mechanical properties of functionally graded hierarchical bamboo structures.

Novel engineered wood and bamboo composites for structural applications: State-of-art of manufacturing technology and mechanical performance evaluation

Production, environmental impact and mechanical properties of glubam

The writers are conducting a comprehensive research program, with the goal to develop modern bamboo structures for buildings and bridges. This paper reports the design, construction, and testing of modern bamboo bridges. Laminated bamboo girders or glubam were developed and verified for satisfactory mechanical performance through full-scale testing. It was demonstrated that the laminated bamboo girders have satisfactory stiffness and load carrying capacity. The use of carbon fiber-reinforced plastics can further enhance the stiffness and capacity of the bamboo girders. Based on the test results and analysis, a 10-m long single lane roadway bridge was designed and constructed, which was the first of its kind in the world. The field tests were carried out using an over loaded two-axel truck with a total weight of 8.6 t which exceeded the given design truckload of 8.0 t. The bridge performed satisfactorily with the midspan deflection corresponding to the critical service loading condition being much smaller ...

Design and Construction of Modern Bamboo Bridges

This study intends to provide a simplified analytical model of the laterally confined concrete filled steel tube (CCFT) column system which adopts carbon-fiber-reinforced polymer (CFRP) jackets in order to make up for major defects of the traditional concrete filled steel tube (CFT) column system. This CCFT analytical model, by adding one additional parameter for CFRP confinement to the CFT column analytical solution, is greatly simplified and expedites the analytical processes to explain the stress-strain relationship of the CCFT column system. In the study, several types of the CCFT column systems with different parameters are analyzed by the proposed simplified analytical model and its associated numerical program (USC-CFT). To verify the accuracy of the analytical model, this study compares the load-strain relationship calculated by USC-CFT both to the experimental results conducted by the traditional method and to the results calculated by the computer-aided finite element method (FEM) analysis metho...

Analytical Model of Circular CFRP Confined Concrete-Filled Steel Tubular Columns under Axial Compression

Effects of sustained axial load and cooling phase on post-fire behaviour of concrete-filled steel tubular stub columns

This paper describes a numerical program to analyze the behavior of the concrete-filled steel tubular (CFT) stub columns, and predict various modes of lateral interactions between steel tube and filled-in-concrete under axial compression. The behavior of the CFT columns is controlled by both the strength and the confinement effect of steel tube and filled-in-concrete in the columns. Various lateral interactions between steel tube and filled-in-concrete in CFT columns are classified into eight different cases by the contact between steel tube and filled-in concrete at different stress stages. The paper examines the analytical models with various experimental results in literature. The comparisons showed that the numerical program is reasonable to capture mechanical behavior of concrete-filled circular steel tubes.

Analytical Studies of Concrete-Filled Circular Steel Tubes under Axial Compression

A split Hopkinson pressure bar equipment was used to perform high strain rate compressive tests on concrete filled steel tubes (CFT) along with benchmark plain concrete cylinders for comparison. This paper reports the results of dynamic compressive strength, ultimate strain, residual strength and the secant stiffness. The dynamic increase factor (DIF) of CFT strength upon the increase of strain rate was obtained based on the logarithm linear fitting of the test results. The DIF of the CFT specimens can be relatively well estimated with conservatism using the simple superposition of dynamic uniaxial strength of concrete and steel. The confinement stress and the confinement coefficient under high strain rate loading are also discussed based on assumptions similar to those used for the static loading cases.

Yan Xiao

Papers

Design and Construction of Modern Bamboo Bridges

Analytical Model of Circular CFRP Confined Concrete-Filled Steel Tubular Columns under Axial Compression

Effects of sustained axial load and cooling phase on post-fire behaviour of concrete-filled steel tubular stub columns

Analytical Studies of Concrete-Filled Circular Steel Tubes under Axial Compression

Experimental Studies on Concrete Filled Steel Tubes under High Strain Rate Loading