Author ORCID Identifier

0000-0002-4798-2051

Document Type

Report

Publication Date

12-2022

Abstract

This study investigated the possibility of developing novel UHP-EGC materials for the repair and new construction of transportation infrastructure in Region 6 by utilizing locally available resources. To this end, the geopolymers (GPs) in this study were synthesized by activating metakaolin (MK) with potassium silicate and sodium silicate solutions. The solutions were manufactured in the laboratory by dissolving silica fume and potassium hydroxide (KOH) or sodium hydroxide (NaOH) in deionized water. MK-based GP binders, mortars, and fiber-reinforced composites were manufactured and evaluated to determine their density, compressive strength, tensile properties, and slant shear bond strength to Portland cement concrete (PCC). Based on the experimental findings, it was concluded that both MG7500 and FA4404 admixtures improved the workability but reduced the compressive strength of the GP. The inclusion of both microsilica sand and UHMWPE fibers (i.e., plasma-treated and pristine UHMWPE fibers) led to an improvement in compressive strength. Plasma-treated UHMWPE fibers exhibited a higher compressive strength compared to pristine UHMWPE fibers. The uniaxial tensile test results revealed that the composites with pristine and plasma-treated UHMWPE fibers at 1.5 vol.% exhibited robust pseudo-strain hardening (PSH) behavior. Furthermore, the best-performing composite (i.e., composite with plasma-treated fibers) exhibited a tensile strength and strain capacity of 6.65 MPa and 6.26%, respectively. The slant shear test revealed that all the materials passed the minimum requirement (i.e., 28-day shear bond strength greater than 13 MPa) to be used as a repair material. While the compressive strength of the developed GP composites using different techniques reached up to 73 MPa, future research should be directed toward the evaluation of hybrid systems (such as MK and slag) to achieve a compressive strength greater than 120 MPa.

Comments

Tran-SET Project: 21CLSU18

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