Date of Graduation

8-2024

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Degree Level

Graduate

Department

Civil Engineering

Advisor/Mentor

Murray, Cameron

Committee Member

Hale, W. Micah

Second Committee Member

Fernstrom, Eric

Keywords

Air void matrix; Concrete pavement; Durability; Freeze-thaw; Optimized gradation; Super air meter

Abstract

Performance Engineered Mixture (PEM) design is a novel method of creating concrete pavement that is economical achieving desirable performance properties such as durability, strength, and workability. Performance-based design is critical for concrete pavements, so the fresh concrete can be placed without issue and the hardened concrete can withstand deterioration and environmental damage such as freezing and thawing. To achieve economical concrete, PEM utilizes tools such as the tarantula curve for aggregate grading, and the Super Air Meter (SAM) test, providing information regarding the air void matrix while the concrete is fresh. To achieve these properties with less cement will lead to decreased material costs, decreased concrete carbon footprint, and decreased durability issues associated with the cement paste. In this study, seven mixtures were developed. Two with aggregate gradations, followed by the same two mixtures with fly ash replacement of cement. A “truly” optimized aggregate mixture with fly ash replacement of cement. And finally, two mixtures with increased air contents. There was a mixture with solely #57 aggregate, a mixture with a blend of #57 and #7 aggregate, a “truly” optimized mixture whose combined gradation is nearly centered on the tarantula curve, and an additional #57 mixture and “truly” optimized mixture with an increased air content to correlate a good SAM number and spacing factor. Each mixture was evaluated by collecting a SAM number, ASTM C666 freeze/thaw test prisms, and a prism to conduct ASTM C457 spacing factor analysis. It was found that cement content in portland cement concrete pavement (PCCP) could be reduced to 440 pounds per cubic yard while maintaining strength, workability, and air content requirements. Aggregate composition in some mixtures had an undesirable effect on freeze/thaw resistance of the mixtures, with permeable or lightweight aggregates performing poorly. Spacing factor data was inconclusive, due to issues concerning the polishing procedure that were encountered during analysis.

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