New Methodology for Evaluating Incompatibility of Concrete Mixes in Laboratory: A Feasibility Study

The current specifications encourage the use of supplementary cementitious materials (SCMs) and as much as possible recycled materials in portland cement concrete. The use of SCMs, especially along with low water-to-cementitious material ratio, low total cementitious material content and cements with a low C3A content and low alkali, can produce some incompatibility in the paste due to the fact that they are not optimized for sulfate content when used with SCMs, or that have anhydrite or hemi-hydrate as the main sulfate source. This situation can create a concrete mixture that is sensitive to changes in ambient temperature, admixture dosage, cement and SCM properties, creating problems in the curing process, developing some early cracking, and compromising the performance of the structure. The following five factors are considered as the most significant factors contributing to the stability of the mixes: (1) type of cement, (2) type of chemical admixture, (3) dosage of chemical admixture, (4) type of SCMs, and (5) testing temperature. A study is proposed to develop an easy to use, relatively inexpensive laboratory test and equipment to determine potential concrete mixture incompatibilities among the aggregates and the above five parameters. The proposed equipment is a miniaturized free-free resonant column (FFRC, ASTM C215) device that has been used by many agencies with success. We have prototyped a fully-automated computer-controlled FFRC device that at user-defined time intervals collects data without the need for a technician. The computer used for this device, can also be readily used to gather temperature measurements from thermocouples. Therefore, the proposed test setup can collect the shear and compression wave velocities as well as the thermal maturity of the material up to an age of 72 hours. It will also utilize a thermal and/or digital imaging processes to estimate the patterns of heat dissipation and shrinkage of the concrete during curing. The proposed device will be assembled and tested for accuracy and precession and will be tested with a number of mixed with different levels of SCM and cement content, among other factors, to establish the feasibility of the system.

Project

  • Status: Active
  • Funding: $232597
  • Contract Numbers:

    DTRT13-G-UTC28

    CAIT-UTC-NC37

  • Sponsor Organizations:

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590
  • Managing Organizations:

    Center for Advanced Infrastructure and Transportation

    Rutgers University
    100 Brett Road
    Piscataway, NJ  United States  08854-8058
  • Project Managers:

    Szary, Patrick

    Rogers, Richard

  • Performing Organizations:

    University of Texas, El Paso

    Center for Transportation Research
    El Paso, TX  United States  78712-1075
  • Principal Investigators:

    Nazarian, Soheil

  • Start Date: 20160601
  • Expected Completion Date: 20180531
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01599967
  • Record Type: Research project
  • Source Agency: Center for Advanced Infrastructure and Transportation
  • Contract Numbers: DTRT13-G-UTC28, CAIT-UTC-NC37
  • Files: UTC, RiP
  • Created Date: May 24 2016 9:14AM