Strain-Hardening cement based composites (SHCC) 5.03

Question 1

Low fiber content=

Answer 1

no optimal utilization of fibers

Question 2

high fiber content=

Answer 2

optimal utilization of fibers

Question 3

what does SIFCON means?

Answer 3

slurry infiltrated Fiber Reinforced Concrete

Question 4

strain hardening behavior: three phase model

Answer 4

Fibers:
-content
-aspect ratio
-tensile strength
Matrix:
-mechanical properties
-flaw distribution
Interphase:
-chemical bond
-friction properties

Question 5

strain hardening behavior: reality vs model

Answer 5

-Matrix: is treated as a homogeneous material, but internal flow dictate the crack initiation
-Fibers: uniformly distributed, fiber distribution affects the final failure (rough approximation)

Question 6

name three levels of failure (at a observation level)

Answer 6

-Macro (cm)
-Meso (mm)
-Micro (micro-m)

Question 7

criteria for multiple cracking: SHCC VS FRC

Answer 7

FRC:
-crack opening keeps increasing
-fibers near the center are pulled out
-load carrying capacity decreases
SHCC:
-crack opening is kept constant
-fibers keep bridging the matrix
-load carrying capacity can increase

Question 8

SHCC properties

Answer 8

-ductile behavior due to multiple cracking
-very high strain capacity
-cracks widths below 0.1mm u to ultimate strain