Table of Contents
Fiber Reinforced Cementitious Composites
Scope of Presentation
Historical Perspective
Fiber Reinforced Concrete
Areas of Application of FRC materials
Properties of Various Fiber types
Hatscheck Method
GFRC Panel Details
Other GFRC projects in California
Experimental Aging Data-Tension Test results
Nature & Role of Interface
Microstructure of CSH
Glass Fiber reinforced Paste
Polypropylene Reinforced paste
Crack Deflection Toughening
Composites with ductile and brittle matrices
Composite Stress-Strain
Reinforcement Due to Short Fibers
Toughening Due to Long Fibers
Stages of Distributed microcracking
Reducing the fiber spacing increases the Tensile
Strength [Romualdi & Batson, 1963]
Toughness
Effect of Fiber aspect ratio on the ductility of
steel fiber concrete in compression
Increasing the Ductility of High Strength Concrete
Voigt Model- (Parallel, Iso-strain model)
Voigt Model- (Parallel, Iso-strain model)
Conventional Strength Theories
Case 1- Matrix and Fiber have the same ultimate
strain
Case 2a- Matrix and Fiber with different ultimate
strain, i.e. Ductile matrix
Elastic Fiber and Elastic Matrix
Fiber Fails first, matrix carries the load
Matrix Fails first, load is distributed to fiber
Composite Response, Vf < Vcrit & emu < efu
Composite Response, Vf > Vcrit & emu < efu
Effect of Fiber Length
Average Fiber stress Effect of Fiber Length
efficiency
ACI based Design Equations
Short Fiber Composite systems
SFRC Mix Design
Mix Design
High Energy Shear Mixing Techniques
Carbon Fiber Composites
Closed Loop Control Flexural Test
Closed Loop Control Tension Test
Fiber Pullout
Strengthening With Carbon Fibers
Toughening-Polypropylene Fiber Composites
Cyclic Loading Unloading Tests - Brittle Carbon
fibers
Fracture Process in LEFM
Three-Point bending Specimen
Compliance based single parameter models
Compliance vs. crack length
Relationship between Stress intensity factor and
strain energy release rate
Compliance Measurements
Effective Crack Length
Stress Intensity Factor
R-Curve Definition
Unloading Compliance
Experimental R-Curve Elastic Analysis
Modeling- Analytical, Fracture Mechanics & FEM
Coupled problem of matrix and interface crack growth
Modeling of Fiber Pullout-FEM Model
Comparison of Fiber Pull out Models with Experimental
Results
Effect of fiber volume fraction
Model Predictions for Effect of Fiber Length in FRC
Composites
Modeling of SFRC
Effect of Fiber Volume Fraction on the
Load-Deflection Response
New Manufacturing Techniques for FRC Materials
Filament Winding Setup
Mold for a Cross ply laminate
Unidirectional Lamina, 3-0 degree plies, 50 MPa (7000
psi) Tensile Strength
Energy Absorption
Polypropylene Based laminates with Vf =7% result in
8% Elongation!
Lamina stacking optimization for strength and
toughness
Theoretical modeling for design and analysis of
composite laminates based on solid mechanics
Extrusion set up
Extruded Composites
Compression Molding
Comparison of Fracture Test for Extrusion and
Compression molded Composites
Innovative FRC Materials-SIFCON
Reactive Powder Concrete
Innovative FRC Materials- Porosity vs. Strength
Conclusions |