Experimental Research On Flexural Performance Of Fiber-reinforced Concrete Plates

Concrete has many outstanding advantages, such as high compressive strength, easy available raw materials, relatively cheap and easy to shape, relatively simple for construction and so on. However, the tensile strength of concrete is really very low, and as the strength increases, the brittleness of concrete increased significantly. So when loaded, the concrete often shows brittle fracture with no obvious signs. That influenced the practical engineering application of concrete greatly. The fibers blended into concrete can significantly improve the tensile strength of concrete. Through resisting the emergence and development of the internal micro-cracks in concrete, fibers can improve the crack resistance and the toughness of concrete.The toughness is an important indicator for the mechanical properties of fiber reinforced concrete, and it can be defined as the capacity of energy absorption of material or structure from loading to failure. The toughness of fiber reinforced concrete includes compression toughness, flexural toughness and shear toughness, etc. Currently flexural toughness is widely used as a measure of toughness of fiber reinforced concrete, because it may give a much better reflection of toughness.Nowadays the traditional method to evaluate the toughness is based on the bending beams (150 mm×150 mm×550mm). However, the formwork of the beam may show some influence on the fiber orientation so that it doesn't correspond to the fiber orientation in the practice very well. In order to minimize this influence and to simulate the loading behavior of industrial panel, according to RILEM, a series simply supported panel (600 mm×600 mm×100mm) test with different fiber types and fiber contents has been carried out at different ages. The load-deflection curves, load-CMOD curves and CMOD-deflection curves have been analyzed. The research results on the energy absorption of FRC notched panels with different fiber types and fiber contents at various deformation stages are presented. In addition, curves also have been created to fit the Load-CMOD curves and the Deflection-CMOD curves and some qualitative analysis has been done on the base of the theory of fiber bonding.