Utilization of fine recycled concrete aggregate and alternative testing for controlled low-strength materials

Henschen, Jacob Daniel

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https://hdl.handle.net/2142/102770 Copy

Description

Title

Utilization of fine recycled concrete aggregate and alternative testing for controlled low-strength materials

Author(s)

Henschen, Jacob Daniel

Issue Date

2018-08-14

Director of Research (if dissertation) or Advisor (if thesis)

Lange, David A.

Doctoral Committee Chair(s)

Lange, David A.

Committee Member(s)

• Popovics, John S.
• Roesler, Jeffery R.
• Mondal, Paramita
• Anderson, Ross

Department of Study

Civil and Environmental Engineering

Discipline

Civil and Environmental Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Recycled concrete aggregate
• Fine recycled concrete aggregate
• Controlled Low-Strength Materials
• Dynamic cone penetrometer testing
• Accelerated curing

Abstract

With ever-increasing emphasis on sustainability, recycling concrete as aggregate has continued to be an important topic. While the use of the coarse fraction of recycled concrete has become commonplace, the fine fraction is largely regarded as a waste material with few outlets for its use. In this thesis, the use of recycled fine concrete aggregate is investigated for use as a source of internal curing in new concrete and as the aggregate in controlled low-strength materials. Characterization of the recycled fine concrete aggregate did not indicate the presence of appreciable quantities of reactive materials, but the recycled aggregates do possess high absorption capacities, which indicates a potential for internal curing. The ability to provide internal curing is tested using autogenous shrinkage measurements. The mixture design method previously develop for controlled low-strength materials is further validated using alternative material combinations. In addition, dynamic cone penetrometer testing and accelerated curing methods are applied to the controlled low-strength material in order to better characterize the strength of the material. The internal curing tests indicated a potential for recycled aggregates to be used for internal curing. The results from the mixture design validation support the previous conclusions that slump flow is highly reliant on the paste volume. The subsidence and strength are both tied to the cement content and the water to cementitious ratio. The findings of the dynamic cone penetrometer tests suggest that it is a viable in situ test for controlled low-strength material. The in situ testing are then correlated with the unconfined compressive strength. Using elevated temperatures to cure controlled low-strength materials did result in significant strength increases over room temperature curing. The higher early strengths from the accelerated curing provides valuable information on the maximum strength that can be achieved from a mixture. The strength gain as a function of time and temperature is modeled for controlled low-strength materials using virgin fine aggregates.

Graduation Semester

2018-12

Type of Resource

text

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http://hdl.handle.net/2142/102770

Copyright and License Information

Copyright 2018 Jacob Henschen

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