Concrete (PCC) Mixture Designs for O

1
Concrete (PCC) Mixture Designs for OHare
Modernization Program
Principal Investigators Prof. Jeff Roesler Prof.
David Lange
PROJECT GOAL Investigate cost-effective concrete
properties and pavement design features required
to achieve long-term rigid pavement performance
at Chicago OHare International.
2
Acknowledgements

• Principal Investigators
• Prof. Jeff Roesler
• Prof. David Lange
• Research Students
• Dong Wang
• Yi-Shi Liu
• Victor Cervantes
• Cristian Gaedicke

3
Former OMP Research Students

• Sal Villalobos CTL, Inc. (Chicago area)
• Civil engineer
• Robert Rodden American Concrete Pavement
  Association (Chicago area)
• Technical director
• Zach Grasley Texas AM
• Materials professor

4
Project Objectives

• Develop concrete material constituents and
  proportions for airfield concrete mixes
• Strength
• volume stability
• fracture properties
• Develop / improve models to predict concrete
  material behavior
• Crack width and shrinkage
• Evaluate material properties and structural
  design interactions
• joint type joint spacing (curling and load
  transfer)
• Saw-cut timing

5
FY2006 Accomplishments
www.cee.uiuc.edu/research/ceat

• Tech Notes (TN) -
• TN21 An Overview of Ultra-Thin Whitetopping
  Technology
• TN23 Effect of Large Maximum Size Coarse
  Aggregate on Strength, Fracture and Shrinkage
  Properties of Concrete
• TN24 Concrete Saw-Cut Timing Model
• TN29 Moisture and Temperature Curling Stresses
  in Airfield Concrete Pavements
• TN30 Fracture Behavior of Functionally Graded
  Concrete Materials (FGCM) for Rigid Pavements
• TN31 Fracture and Drying Shrinkage Properties of
  Concrete Containing Recycled Concrete Aggregate
• TNXX Overview of GGBFS for Concrete Pavements
  (95)

6
Presentation Overview

• 2006 Review
• Large-sized coarse aggregate mixtures
• FGCM
• Recycled Concrete Aggregate Concrete
• Moisture/Temperature Curling
• Saw-cut timing model
• Field Demo Project
• Crack width-Curling prediction
• 2007 Work Plan

7
PCC Mix Design Phase II

• Summary
• Larger aggregates reduce strength by 20, but
• 28-day GF similar ? similar cracking resistance
• Larger aggregates reduce concrete brittleness
• 1-day fracture energy ? with larger MSA
• ? greater joint stiffness / performance
• No significant shrinkage difference
• TN23 April 2006

Roesler, J., Gaedicke, C., Lange, Villalobos,
S., Rodden, R., and Grasley, Z. (2006),
Mechanical Properties of Concrete Pavement
Mixtures with Larger Size Coarse Aggregate,
accepted for publication in ASCE 2006 Airfield
and Highway Pavement Conference, Atlanta, GA.
8
FGCM Pavement Systems
Figure 1. Multifunctional and functionally graded
concrete material (FGCM) under temperature (T),
relative humidity (RH) and mechanical loading
(P), where fi fiber type and volume content for
layer i. Here hilayer thickness, Eielastic
modulus, ?iPoissons ratio, ?icoefficient of
thermal expansion Didiffusivity coefficient,
kithermal conductivity, and ?ilayer density
9
Experiment

• Composite beams
• Single edge notch fracture
• PCC and FRC combinations
• Full-depth or bi-layered
• Material Strength
• Compressive
• Split-Tensile

10
Numerical vs. Experimental
Numerical Results
Experimental Results
11
Recycled Concrete Aggregate (RCA)

• Determine the fracture properties of concrete
• virgin and recycled coarse aggregate
• w/ and w/o structural fibers
• Effects of concrete drying shrinkage with
  recycled coarse aggregate

12
Mixture Proportions
13
Results Virgin, RCA, 50-50

• Similar peak loads
• Virgin GF is similar to the 50-50 GF
• Virgin GF is 1.6 times larger than RCA GF

14
Virgin, RCA, 50-50 with FRC

• Similar peak loads
• Similar softening curves
• Similar GF

15
RCA Shrinkage
16
Saw-Cut Timing and Depth

• Process

• Concrete Mix
• Aggregate size
• Cementitious content

Crack Propagates
FRACTURE PROPERTIES
Wedge Split Test
FEM Model
Saw Cut Depth Model
17
Summary of Notch Depth Requirements
18
Concrete Slab Behavior

• Curling stresses
• temperature
• moisture
• Joint Opening
• Load transfer
• Dowel vs. no dowel

19
Moisture Curling

• Effects of materials and slab geometry on
  moisture and temperature curling

after Grasley (2006) Rodden (2006)
20
Field vs Lab
Lab
Field
21
Field Validation

• Field data three concrete slabs were cast on
  06/22/06 at ATREL
• Slab size 15x12x10, BAM
• Temp., RH measured _at_ surface, 1,3,5,7
  and 9 at 15-min. interval
• Two LVDTs installed in each joint to measure
  joint opening

22
Joint Opening Measurement
23
Three month joint opening
24
Joint opening (?)
25
Predicted joint opening
26
FY 2007 Work Plan

• Objectives
• Predict early-age behavior of concrete pavement
  based on interaction of design, construction
  techniques, material constituents and
  proportions, and climatic conditions.

27
FY 2007 Tasks

• Concrete Mixture Evaluation
• Combined aggregate gradation
• GGBFS
• Temperature / Moisture Prediction
• Construction factors
• Mixture variables
• Climatic variables
• Design factors

28
Principles of Design Optimized Concrete

• Minimize Voids to reduce cement paste volume
• Higher sand fraction and well graded CA (2 sizes)
  needed
• Polycarboxylate superplasticizer to achieve
  workability

29
Particle Packing

• Continuous grading reduces void volume
• Mathematical models can predict max density from
  particle sizes

30
Properties of DOC

• Similar or higher strength compared to OPC
• Reduced shrinkage
• Reduced bleeding and segregation
• Better workability (with vibration) and
  finishability (no waiting)

31
Cost savings with DOC
32
Ground Granulated Blast Furnace SlagGGBFS
33
Introduction

• By product of the steel industry
• Produced in blast furnaces
• Highly cementitious
• Hydrates similarly to Portland cement

34
Pros and Cons
Cons
Pros

• Improves workability
• Lower water demand
• Higher paste volume
• Higher strength potential
• Using 120 grade
• Longer setting time
• Decreased permeability
• Performs well in freeze thaw tests
• Reduces the effects of ASR

• Reduced heat of hydration
• More susceptible to drying shrinkage
• Slower strength gain

35
GGBFS

• Fracture and Strength properties
• Shrinkage properties
• Dan Ryan Expressway mixture

36
Heat Transfer Problem Early Age Concrete Pavement

• Predict temperature profile in concrete pavement
  at the early age
• Sensitivity studies
• - Asphalt Concrete initial temperature
• - Mix/construction temperature (nighttime)
• - Mixture constituents (cement content / type,
  thermal properties, etc.)
• -climatic effects
• Construction questions
• - Curing methods and nighttime construction
• - Saw-cut timing curling stresses

37
Surface Energy Balance
Solar radiation
Reflected radiation
Convection
Wind
Conduction
PCC slab
BAM
ASB
Subgrade
Conduction
38
Heat Transfer Model Theoretical Background

• N-layer Pavt system

• Governing PDE

Layer 1
Layer 2
Layer
Layer
39
Heat of Hydration

• Heat of hydration of cementitious material is
  modeled as 1
• 1 Emborg, M., thermal stresses in concrete
  structures at early ages, doctoral thesis, Lulea
  Univ. of Technology, Sweden, 1989

40
Boundary Condition

41
Numerical Methods

• Spatial discretization
• Finite difference schemes

PCC

• Time integrator
• 2nd-order semi-implicit backward
• differentiation formula

Base
Subgrade
42
Sample Results

• Temperature profile prediction (no term,
  based on uniform initial temperature profile T
  40 ?F, and linear air temperature assumption)

43
Field Data Requirements

• Weather data
• Air Temperature, wind speed, solar radiation
• Concrete final set time
• Concrete mixture proportions
• Cementitious composition
• Field instrumentation
• Initial concrete mixture temperature
• Curing conditions
• Temperature / moisture profile

44
Temp / Moisture Profile Outcome

• Concrete Pavement Behavior Predictions
• Saw-cut timing and depth
• Early-age curling stresses (slab model)
• Joint opening prediction

45
QUESTIONS

• www.cee.uiuc.edu\research\ceat
• Thanks!