Structural Engineering and Computation, Capetown, South Africa, 10 - 12 September 2007, pp.1961-1966
ABSTRACT: The limited strain capacity of cementitious materials makes them tension-weak, brittle, and considerably notch sensitive. Textile fabrics have been recently developed as a new class of cement based materials with considerable improvement in strength and ductility. In this study use of pultruded cement fabrics in increasing the flexural capacity of concrete subjected to flexural loads are studied as a potential strengthening method. Plain concrete beams with size of (100×100×460 mm) were produced. Samples were strengthened by using alkali resistant (AR) glass and polyethylene (PE) fabrics impregnated with cement paste. Two levels of strengthening
consisting of four and eight layers fabric were used on five replicate specimens in each category. Three point bending tests were performed on a closed-loop controlled servo-hydraulic material test system. The strengthened concrete beams were subjected to monotonic and cyclic flexural loads to determine the effects of strengthening process, type, and number of fabric layers on the flexural behavior of concrete beams. The recorded measurements on the test specimens were evaluated from the viewpoint of flexural strength, ultimate deflection, and rigidity degradations of specimens. The fabric reinforced concrete composites (FRCC) significantly contributed on the flexural load carrying capacity, ductility, and rigidity of concrete beams. The contributions of these composites varied according to fabric type and amount of fabric layer. The increase in the flexural capacity was also associated with the apparent change in the mode of failure from a flexural mode to shear mode.
Keywords: Pultrusion, fabric, cement paste, cyclic, flexural, ductility, strengthening, concrete beam