Development of an Extremely Durable Concrete (EDC)– A Novel Approach Coupling Chemistry and Autogenous Crack Width Control

Victor Li, University of Michigan

Team Members: Kimberly Kurtis Georgia Institute of TechnologyPaulo Monteiro University of California Berkeley

Enhancing concrete infrastructure service life by 5 foldTotal Project Cost: $1.9 MLength 24 mo.

Project Vision

Enhancing durability by chemistry and crack control

Result: No repeated repairs, lowers energy consumption and O&M cost of infrastructure

Current infrastructure: Cracking is a key structural degradation mechanism; unreliable control

Future infrastructure: Crack control and self-heals

The Team

PILi

Co-PIKurtis

Co-PIMonteiro

University of MichiganGeorgia

TechUC

Berkeley

Project Management with ARPA-E

AdvisorScrivener

Sub-groups Main focusMichigan Group Project coordination, composite development and extreme durability

investigation and verification

Georgia Tech Group Cement chemistry and particle packing

Berkeley Group Micro- and nano- characterization

EPFL

We will deliver a suite of EDC products within 2 years

Goal: To achieve an EDC with life expectancy five times that of current concrete

Duration: 2 years (10/2019 – 09/2021)

Final Deliverables:

– Compressive strength: three levels > 20 MPa, 30 MPa and 40 MPa

– Tensile ductility > 3%

– Crack width < 50 μm

The goal will be achieved by coupling chemistry and crack control

Durable Binder: Limestone Calcined Clay Cement (LC3)

Crack Width Control and High Ductility: Microfiber bridging (Engineered Cementitious

Composites, ECC)

ECC controls crack width in an autogenous manner

Typical ECC

Crack width < 100 μmTensile ductility > 3-5%

We are formulating preliminary EDC in Year 1

Q1 Q4

Material Development

Q6 Q8

Durability Demonstration

Material Optimization

We are currently at Q4 for preliminary EDC with tensile ductility > 2%

PE PVA Nylon PP Aramid PBO PET Steel Basalt Carbon Glass --

0

1

2

3

4

5

6

7

8

9

Com

posit

e Ten

sile S

train

Capa

city,

%

Fiber Type

Typical strain capacity of PVA-ECC

PP fiber was chosen due to low cost and high composite ductility

SteelPVA

PPPET

PEPBO

NylonGlass

CarbonBasalt

AramidAcrylic

0 20 40 60 80 100 120 140 160 180 200

PVA fiber cost range

Fiber cost per unit volume, 1000 US$/m3

Mono and/or hybrid fiber systems are examined for EDC

EDC achieves tensile ductility >8% at 28 days using PP fibers

PP Fiber + Non-Optimized LC3 Binder

Tensile Strength = 2.9 ± 0.3 MPaTensile Strain Capacity = 8.4% ± 1.2%

Fiber diameter = 12 µm

Average crack width = 56 µm when loaded to 2%

Fiber pulled out at fractured surface

EDC will be optimized on pore/flaw network and crack localization

UC Berkeley Group is employing micro-CT to understand the role of pore/flaw network in EDC crack localization and composite ductility

PP Fibers

500µm

Pore/Flaw

Crack

Challenges and Strategies

Challenges:1. Control crack width down to < 50 μm while keeping tensile ductility > 3%2. Ensure desirable EDC workability and polymeric fiber dispersion

Strategies:1. Adopt ECC micromechanical framework to guide EDC design2. Tailor LC3 particle design and formulations to optimize EDC rheology

Potential Partnerships

We welcome collaborations in• Standardizing EDC for field applications

• Developing large-scale testbeds to demonstrate extreme durability at scale

We offer capabilities of• Innovating strategies for controlling crack width for durable binders

• Optimizing micromechanical design for fiber-reinforced cementitious composites

Summary

Concept: Durable Chemistry + Autogenous Crack Width Control

Team: University of Michigan (Leading Institute)Georgia Tech & UC Berkeley

Goals: Low-energy concrete with 5X durabilityBuilt-in self-healing capability to lower O&M cost and energy consumption

Development of an Extremely Durable Concrete (EDC)�– A Novel Approach Coupling Chemistry and Autogenous Crack Width Control���Victor Li, University of Michigan��Team Members: �Kimberly KurtisGeorgia Institute of Technology�Paulo MonteiroUniversity of California BerkeleyEnhancing durability by chemistry and crack control The TeamWe will deliver a suite of EDC products within 2 yearsThe goal will be achieved by coupling chemistry and crack control ECC controls crack width in an autogenous mannerWe are formulating preliminary EDC in Year 1PP fiber was chosen due to low cost and high composite ductilityEDC achieves tensile ductility >8% at 28 days using PP fibersEDC will be optimized on pore/flaw network and crack localizationChallenges and StrategiesPotential PartnershipsSummarySlide Number 14