The purpose of this research was to experimentally characterize the flexural and tensile characteristics of fiber-reinforced Very High-Strength Concrete (VHSC) panels. The panels were made with a unique mix of cementitous materials achieving compressive strength of 26,000 psi (180 MPa) or greater. VHSC panels were reinforced with polypropylene fibers of 1 inch (25.4 mm) in length and Polyvinyl alcohol (PVA) micro-fibers of ½ inch length, incorporated at 1.5% by volume. For the flexural behavior, 17Ã2þ inch flat panels were tested under third-point loading tests, while the direct tension experiments were tested on 10Ã3ý inch tension panels under a direct tensile load. Flexural tests were conducted on three panels of plain VHSC, three panels of VHSC reinforced with polypropylene fibers and three panels of VHSC reinforced with ½ inch micro-fibers. Similar testing program was used to conduct the direct tension tests. Also, compression test conducted on 2Ã2Ã2 inch cubes and compressive test conducted on 4 inch by 8 inch cylinders test were used to establish compressive strength and modulus of elasticity respectively. Results show that the compressive strength, tensile strength and fracture toughness of the VHSC panels were much greater than those normally obtained by typical concrete material. The presence of fibers increases the toughness of VHSC specimens between 80 and 190% and increases the tensile strength by 23 to 47%. The modulus of elasticity and Poissonâs ratio recorded herein were determined according to ASTM C 469-02. Laboratory experiments on flexural and tensile properties of thin, very high-strength, fiber reinforced concrete panels, were used to study the material and characterize the panelsâ reaction to load. Parameters such as compressive strength, tensile strength, toughness, elastic modulus, Poissonâs ratio and first-crack strength were determined and may be considered for potential use as design parameters in future material improvements
Problem statement: Thermodynamically, particles in composites will arrange in a way such that the Helmholtz free energy is minimized. However, even a single structure has the lowest free energy, it should not ignore the probability of other structures having larger energies to occur, although at small chances. Approach: All possible arrangements of particles in the composites, therefore, must be taken into account in the theory or simulation development. Results: The composite energy depends on the interaction between components in the composites. To consider the effect of interactions on energy, in this study we used a simple Ising model incorporated with the BraggWilliams approximation. We used the model to predict the average packing fraction and the percolation threshold in composites as well as other quantities related to percolation phenomenon. Conclusion/Recommendations: We found several predictions that have not been reported by previous authors. This model can be important in the understanding conductivity development in electrically conductive adhesive composites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.