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600451-00053

SWUTC Ph.D. Candidate Assistantship Project Description

Modeling and Measuring Deformation of Freezing Concrete: Towards the Identification of D-Cracking Susceptible Aggregates and Construction of all Concrete LNG Tanks

University: Texas A&M University

Principal Investigator:
Syeda Rahman
Zachry Department of Civil Engineering

Faculty Supervisor:
Dr. Zachary Grasley
Zachry Department of Civil Engineering
(979) 845-8865

Funding Source: USDOT Funds

Total Project Cost: $37,592

Project Number: 600451-00053

Date Started: 10/1/15

Estimated Completion Date: 8/31/15

Project Summary

Project Abstract:
Little work has been done to investigate the role of mechanics and constitutive properties of concrete phases in the formation and growth of damage in concrete due to freezing of aggregates. Present model needs to be modified to account for the presence of dissolved salts and its subsequent effect on the liquid saturation to accurately predict concrete deformation cooled to cryogenic temperatures.

Project Objectives:
Primary objectives of this research include:

  1. Derive a thermoporomechanical model.
  2. Incorporate the effect of dissolved salts and viscoelasticity in the deformation and the successive internal stresses in freezing concrete
  3. Investigate the role of constitutive properties of concrete phases in the formation of damage via computer simulations implementing the derived model
  4. Use the developed model to evaluate structural design of LNG tanks
  5. Measure deformation of concrete subjected to freeze-thaw cycles
  6. Quantify damage caused by freeze-thaw cycles
  7. Design an experimental setup
  8. Provide a guideline on the concrete mixture design

Task Descriptions:

Task 1 – Literature Review:

Task 2 – Modeling concrete under freezing temperatures:  Theory of thermoporoelasticity

Task 3 – Improving the existing theory

Task 4 – Measure concrete deformation and quantify damage

Task 5 – Provide guidelines for engineering practice