CEAT Workshop on moisture & Temperature modeling in concrete pavements
July 9-10, 2007
The CEAT Workshop on "Moisture & Temperature Modeling for Concrete Pavements" was held on July 9-10, 2007 at the University of Illinois at the Beckman Institute. The workshop included formal presentations, but with an abundance of time for open discussion. The workshop was not meant to be a conference style event, but rather a small group of experts in discussion about the technical approaches and barrieres encountered in modeling these complex behaviors. The contributions of the participants in the workshop were essential to making this discussion valuable.
Following is the list of attendees, topics of discussion and short presentations:
ATTENDEES
- David Lange, CEAT Director (UIUC)
- Dan Zollinger (Texas A&M)
- Dan Ye (Texas A&M)
- Zach Grasley (Texas A&M)
- Shelley Stoffels (Penn STate)
- Edward Guo (SRA - consultants to NAPTF)
- Ben Mohr (Tennessee Tech University)
- Jason Weiss (Purdue University)
- Salah Altoubat (University of Sharjah)
- Jeff Roesler (UIUC)
- Wang Dong (UIUC)
- Matt D'Ambrosia (UIUC)
- Yi-Shi Liu (UIUC)
- Chang Joon Lee (UIUC)
- Logistics: Vicki Dixon, CEAT Assistant to the Director
SUNDAY JULY 8
Casual dinner in campus town for hose arriving early, meet in Hampton Inn Lobby
MONDAY JULY 9 - Location: Beckman Institute, 5th Floor Tower Room (5269 Beckman)
8:30 - Welcome and Overview -- Lange
9:00 - Measuring moisture and internal relative humidity
Sensors, interpretation of values, temperature effects
Presentations:
Grasley, Measuring moisture and internal RH
Zollinger, RH measurement in concrete
Mohr, Internal curing for HPC shrinkage mitigation
Roesler, Relative humidity measurements - ATREL field testing
Lange, Internal RH & tempature relationship
11:00 - Measuring strain
Embedded gages and sensors, interpreting stress and strain, measuring residual stress, viability of "stress" sensors
Presentations:
Stoffels, Thoughts based on work funded by IPRF and conducted at the NAPTF with the cooperation of the FAA
D'Ambrosia, Temperature compensation for early age concrete testing
Liu, Measuring drying shrinkage strain of paste
Guo, Verification of strain reliability measured at NAPTF
12:00 - Lunch
1:00 - Measuring cracks
Displacement sensors, acoustic emission sensors, fiber optics, visual observation
Presentations:
Roesler, Concrete crack width measurements
Weiss, Acoustic emission for crack assessments
Guo, Mechanism related findings in crack measurement at the NAPTF and its impact to design specifications
2:30 - Modeling moisture & temp gradients
Diffusion of moisture, thermal conductivity, daily/seasonal environmental cycles
Presentations:
Ye, Temperature and moisture modeling
Mohr, Internal curing model
4:00 - Material modeling
Constitutive models, converting excitations (strains) to stress, damage, microcracking,
time-dependence of properties, fracture mechanics vs strength criteria
Presentations:
Grasley, Constitutive modeling
Altoubat, Damage approach toward predicting cracking of restrained concrete
Zollinger, Material characterization
D'Ambrosia, Coupled rheological model for concrete creep and shrinkage
6:30 - Group Dinner in downtown Champaign
TUES JULY 10 – Location: Newmark CE Lab Quade Lounge
8:30 - Structural modeling
Implementations of material models into structural models, interfaces, homogeneous
vs composite, cracking
Presentations:
Roesler, Moisture curling stresses in concrete pavements
Ye, Modeling of concrete slab curling and warping
Lee, Moisture curling of NAPTF slab test
Guo, Effects of the variation of concrete modules (E) on the response and failure model; Validity of 3D and 2D models and pending questions; Interation between full scale test and mechanistic model may approach a cost effective research procedure
11:00 - Panel discussion
What gaps of technology are most urgent to resolve? Needs for standardization? What are best methods? What data do models of the furture need? What are furture challenges? What applications need our attention? Discuss potential collaborations.
12:00 - Adjourn