Applications of UHPC Pakistan Academy of Engineering December 28, - PowerPoint PPT Presentation

Applications of UHPC Pakistan Academy of Engineering December 28, 2019 Tariq M. Bashir, PE

UHPC Ultra-high Performance Concrete (UHPC) ▪ Steel fibers to enhance cracking resistance and ductility ▪ High compressive and tensile strengths ▪ Exceptional durability ▪ Self-consolidating ▪ Absence of coarse aggregate (mortar) ▪ High binder content ▪ Low w/cm ▪ High particle packing density ACI 249 defined UHPC as: “ Concrete, ultra-high performance – concrete that has a minimum specified compressive strength of 150 MPa (22,000 psi) with specified durability, tensile ductility and toughness requirements; fibers are generally included to achieve specified requirements.” 2

Design of cost-effective UHPC Steel fibers • Strategies ➢ Use high-volume by-products (e.g. fly ash & slag) to partially Water replace cement Sand ➢ Use cost-effective sand to replace fine ground silica sand Admixtures ➢ Reduce steel fiber content Binder ➢ Reduce binders (silica fume) (cement, fly ash, content slag, silica fume) Components of UHPC Meng W, Valipour M, and Khayat KH. Optimization and Performance of Cost-Effective Ultra-High Performance Concrete, Materials and Structures 2016 , 50(1), 29.

Advantages of UHPC • Resilience ➢ High mechanical strengths ✓ Compressive strength (28 days): ≥ 120 MPa ✓ Tensile strength (28 days): ≥ 7 MPa ➢ Strain-hardening behavior UHPC UHPC Compressive stress Tensile stress FRC HPC CC CC 0 0 Compressive strain Tensile strain UHPC: ultra-high performance concrete FRC: fiber-reinforced concrete HPC: high-performance concrete CC: conventional concrete

Useful Properties 1. Strength 2. Strong Bonding 3. Moldability 4. Impermeability

Development Length Tests #4 BARS (BLACK & EPOXY) – 3” EMBEDMENT #5 BARS (BLACK & EPOXY) – 4” EMBEDMENT #6 BARS (BLACK & EPOXY) – 5” EMBEDMENT

Advantages of UHPC • Super workability (self-consolidating) ➢ Low construction energy (no mechanical vibration for consolidation) ➢ High construction quality 280 mm

Applications of UHPC in civil infrastructure Sherbrooke foot bridge, Canada, 1998 Bridge girder connection, New York, 2010 Precast bridge deck, Iowa, 2012 Bridge overlay, Switzerland, 2015

France Canada Longer spans, shallower depths, lighter weight Kora Japan 10

• Simple Lap-Splice Cxn. • Smaller Grout Volumes • Shortened Bar Lengths • Emulates Monolithic Component

6 in. 96 in. Precast Deck Panels 8 in. UHPC Closure Pour and Slabs Precast Deck Panel 61 in. 6 in. Deck Bulb Tee Girders Closure Pour (UHPC) 41 in. Deck Bulb Tee Prestressed Girder

Joint Testing by FHWA for Strength Durability and Performance •  8” THICK PANEL - #4 EPOXY COATED HAIRPIN BARS  8” THICK PANEL - #5 GALV. STRAIGHT BARS (6” LAP)  8” THICK PANEL - #5 BLACK STRAIGHT BARS (6” LAP)  8” THICK PANEL - #5 BLACK HEADED BAR (3 ½” LAP)  6” THICK PANEL - #5 BLACK STRAIGHT BARS (6” LAP)  6” THICK PANEL - #5 BLACK HEADED BARS (3 ½” LAP)

Test Conclusions 1. Joint system emulates or surpasses C I P monolithic decks hence can be designed similar to CIP decks 2. No interface de-bonding during testing was observed 3. No de-bonding of reinforcing bars during testing

Link Slab Deck Haunch Girder Link Slab Section

Why use Link Slabs? • Elimination of deck joints ▪ Leakage - accelerated deterioration of girder ends, bearings, substructures ▪ Frequent maintenance ▪ User comfort

Why use Link Slabs? • Simple span behavior retained ▪ Girders function as originally designed • Economical means to eliminate joints

How do they work? • Ends of deck are connected or linked together • Pinned connection in slab • Girder’s point of rotation moved from bearing to link slab • Translation due to girder’s rotation moved from joint to bearing

Deck Joint

Link Slab

UHPC Link Slab

Finished Link Slab

Precast Pier Elements

Bridge Deck Overlay

Repair and protection of foundations and supports (AFGC, France) Enhanced durability and accelerated construction

Architectural Applications

Rotman School of Management (expansion) Toronto, Canada Designer: KPMB Architects Built: 2012 Dimensions: panels 0.5 m to 1.0 m wide x 3.5 m to 5.3 m high x 2.5cm thick Fabricator: Armtech

Rotman School of Management (expansion)

Dumbo Lofts 28 UHPC panels Each panel is 18 ft x 11 ft Ribs 10 in Back pan ¾ in thick Ribs taper from 4 in to 1 ¼ in thick Fabricator: Gate Precast

Tower La Marseillaise Marseille, France 135 M Tall Flat Panels, Shade Louvers, Lattices

Tower La Marseillaise

Nike Flagship Store Miami, Fl Designer: Nike Built: 2016 Dimensions: panels 4’ x 4’ Fabricator: DEX Industries

Nike Flagship Store

TGV Station Montpellier Montpellier, France Designer: Marc Mimram Built: 2017 Dimensions: roof 18m x 2m x 5cm Fabricator: Mêditerranêe Prêfabrication

TGV Station Montpellier

MUCEM Marseille, France Designer: Rudy Riciotti Built: 2012 / 2013 Lattice Panel Dimensions: 6m (19.6 ft) x 3m (9.8 ft) 7cm (2.7 in) thickness roof panels and 10 cm (3.9 in) thickness wall panels Fabricator: Bonna Sabla

MUCEM Columns: 3 stories, Post Tensioned Pedestrian Bridge: 360 foot free span. Post tensioned world record for slenderness

Drop Stair London, England Designer: Zaha Hadid Built: 2012 Fabricator: Il Cantiere

Questions