Deflection and Cracking Behavior of Ferrocement with Grouped Reinforcement and Fiber Reinforced Matrix
R. N. Swamy and A. Spanos
Appears on pages(s):
cracking (fracturing);crack width and spacing; deflection; ductility; ferrocement; fiber reinforced concretes; flexural strength; fly ash; reinforcing materials; stiffness; workablity.
This paper presents two aspects of ferrocement technology. First it is shown that grouping the reinforcemnt meshes at top and bottom and tying them to skeletal bars into a rigid cage simplifies fabrication compared to conventionally spaced meshes and insures the desired location of the meshes. Cement replacement by 50 percent fly ash and inclusion of a super plasticizer can produce mixes of excellent flow characteristics and adaquate early strength that can further ease the construction process and enable incorporation of fibers without difficulties of fabrication. Second, it is shown that fiber reinforcement along with the new steel arrangement increases stiffness, decreases deflection, and shows large ductility at failure. The fiber reinforcement also results in substantial reductions in crack spacing and crack width compared to conventional ferrocement. Equations are presented to predict average crack spacing and crack width.