Ultra High Performance Fiber Reinforced Concretefor structural applications

D. Redaelli – Supervisor Prof. Dr A. Muttoni

• Acquire a better knowledge on the interaction between UHPFCR and ordinary reinforcement in the tensile zones of structural elements.

• Model the structural response of different type of reinforced UHPFRC elements.• Define suitable applications for UHPFRC with and without ordinary reinforcement.

Objectives of the Research

« Reactive powder matrix » :High compressive strength and

High compactness+

2% in volume of short steelfibres for ductility

Ordinary Concrete UHPFRC

Compressive strength 30-80 200 MPa Young modulus 30 60 GPa Tensile strenght (matrix) 3 10 MPa Tensile strength (fibers) - 12 MPa

With a strain hardening behaviorin pure tension

1.00

m

• New test set up for reinforced members in tension

- 1.6 m long 160 x 160 mm specimens- High force potential : 180 tons

• Crack pattern development and strain localization mechanism followed up to failure

• Influence of the type and amount of steel reinforcement on the structural behavior

Hot-rolled / Cold-worked steel1. Behavior at peak load2. Strain at failure

0

200

400

600

800

0 5 10 15 20Strain [%]

Stre

ss [M

Pa]

Hot-rolled steel

Cold-worked steel

0

300

600

900

1200

0 8 16 24Elongation [mm] (measure length 1.00 m)

App

lied

forc

e [k

N]

Keywords

Test seriesand results

UHPFRC

Ultra high performance concrete, fibres, strain hardening in tension, tensile members, ordinary reinforcement, ultimate limit state.

IS-BETON

Poster n° 49