Abstract

The use of edge-oxidized graphene oxide (EOGO), produced by a mechanochemical process that allow to deliver a product suitable for large-scale production at affordable cost, as an additive in cement composites was investigated. Comprehensive experimental tests were conducted to investigate the effect of EOGO on the properties of cement composites. The experimental tests were designed for three subtasks: (1) investigation of the performance of EOGO and its mixing method on the strength, pore structure and microstructure of EOGO-cement composites, (2) evaluation of the rheological and fluidity behavior of EOGO-cement paste and mortar, and (3) investigation of the mechanism of the enhanced workability of EOGO-concrete. EOGO content ranged from 0.01% to 1% and two mix design methods were employed for cement paste and mortar to explore an optimum and feasible mix design of EOGO. Compressive and flexural strength tests were conducted to investigate the mechanical performance of EOGO-cement composites. Total porosity and water sorptivity were performed to investigate the pore structure of EOGO-cement paste and mortar. Furthermore, petrographic analyses were conducted to characterize the microstructure of EOGO-cement composites. Imaged based-mini-slump and flow table tests were performed to measure the fluidity of EOGO-cement paste and mortar. The rheological properties of EOGO-cement paste were measured through viscometer test. The mechanism of the enhanced workability of EOGO-concrete was investigated by performing slump and water absorption of aggregate in cement paste tests. The key findings are (1) the addition of EOGO into cement composites improves the compressive and flexural strength, (2) 0.05% of EOGO is the optimum content to improve the strength and pore structure of EOGO-cement composites, (3) the addition of EOGO reduces the fluidity and increases the viscosity of EOGO-cement composites, (4) the addition of EOGO improves the workability of concrete, and (5) dry-mix design is feasible and more practical for large-scale production.

Notes

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Graduation Date

2019

Semester

Spring

Advisor

Nam, Boo Hyun

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Civil, Environmental, and Construction Engineering

Degree Program

Civil Engineering

Format

application/pdf

Identifier

CFE0007425

URL

http://purl.fcla.edu/fcla/etd/CFE0007425

Language

English

Release Date

May 2020

Length of Campus-only Access

1 year

Access Status

Doctoral Dissertation (Campus-only Access)

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