STUDY OF STRENGTH AND DURABILITY OF HIGH STRENGTH CONCRETE USING CARBON FIBER

Abstract

The presented work investigated the mechanical properties, impact resistance (with a modified ACI test setup), and durability of high strength concrete by reinforcing it with four different aspect ratios i.e., 100, 150, 200, and 250 of carbon fibers with varying dosages of 0.2, 0.4, 0.6, 0.8, and 1% fiber content. Various tests, including flexure tests, impact resistance tests, ultrasonic pulse velocity tests, compression tests, and durability test, were performed on test samples after 28 days of curing period with water. Energy dispersive X-ray spectroscopy along with Powdered X-Ray diffraction analysis was carried on samples to find out various chemical compositions of elements present and mineralogical properties respectively. The surface morphology of concrete samples was determined with the help of Scanning electron microscope (SEM) equipment. Functional groups and metal linkages were confirmed by Fourier Transformed Infrared spectroscopy (FTIR). The presence of atoms or elements were determined by X-Ray Photoelectron spectroscopy (XPS). The mechanical characteristics and impact resistance were connected with an analytical analysis technique. The carbon fiber with the largest aspect ratio of length equivalent to 25mm, showed good growth in the rate of flexural, compressive strength and impact resistance. SEM images revealed that the primary cause of failure in carbon fibers was the debonding of fibers at fracture surfaces. The increase in carbon fibers content or dosages enhances the compressive strength, flexural strength, impact resistance, durability and optimum dose of fibers enhanced the porosity of concrete specimens. Chemical examination showed that silicon and calcium vii crystalline were the primary components of the concrete matrix, which suggested that calcium silicate hydrate and calcium hydroxide were the primary hydration products of the cement-based matrix.