Masters Theses

Keywords and Phrases

Concrete; Fly-Ash; High Volume Fly-Ash; Infrastructure; Sustainability

Abstract

"This study was performed to examine the effects of cement replaced by high volumes of Class C fly-ash on durability characteristics of concrete up to 120 days. Specifically, this study investigates possibility of amending American Society for Testing and Materials (ASTM) to allow High Volume Fly-ash (HVFA) concrete to cure until later ages prior to testing instead of 28 days. Five mix designs were compared with varying fly-ash percentages from 0 to 70% (by total cementitious mass). No other additives were present in any of the five mix designs. Water-to-cementitious ratio (w/cm) and total cementitious material remained constant as 0.40 and 750 pounds per cubic yard respectively.

Both plastic concrete and hardened concrete properties were examined. The replacement of cement by fly-ash resulted in the concrete exhibiting adequate 28 day strength, stiffer moduli, lower chloride permeability, improved resistance to freezing and thawing, and improved abrasion resistance at 50% fly-ash replacement when compared to a baseline mix. At 70% fly-ash replacement, the concrete never reached equivalent properties to the other mixes. As the age and compressive strength of all mixes increased, so did the abrasion resistance and durability factor. Accelerated curing at 100⁰F (37.8⁰C), 130⁰F (54.4⁰C), and 160⁰F (71.1⁰C) proved to be detrimental to the concrete at all fly-ash levels, with higher temperatures causing increased damage. An increase in compressive strength was seen in the first few days prior to a decrease in compressive strength"--Abstract, page iii.

Advisor(s)

Myers, John

Committee Member(s)

ElGawady, Mohamed
Sneed, Lesley

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Civil Engineering

Sponsor(s)

Missouri. Department of Transportation

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2015

Pagination

xvi, 161 pages

Note about bibliography

Includes bibliographical references (pages 155-160).

Rights

© 2015 Kaylea Ann Smith, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Concrete -- Additives
Reinforced concrete -- Testing
Fly ash -- Testing

Thesis Number

T 10801

Electronic OCLC #

936209446

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