Doctoral Dissertations

Weina Meng

Abstract

"This study presented in this thesis aims to: (1) develop a mixture design methodology for cost-effective ultra-high-performance concrete (UHPC) incorporating high volume of supplementary cementitious materials and conventional concrete and masonry sands; (2) developed UHPC with adapted rheology incorporating lightweight sand, hybrid fibers, and nanomaterials with improved properties; (3) design prefabricated UHPC panels with fiber-reinforced polymers (FRP) for enhanced flexural properties of stay-in-place panels made with optimized UHPC; and (4) explore potential applications of such UHPC elements. The proposed design methodology produced UHPC mixtures with 28-days compressive strengths higher than 125 and 168 MPa under standard water curing and 1-d steam curing at 90 ⁰C. To further improve the properties, internal curing using pre-saturated lightweight sand, rheology control of the suspending mortar before steel fibers addition, and reinforcement of hybrid fibers and carbon nanomaterials, were employed. The outcome indicated: (a) the optimum replacement ratio of lightweight sand to river sand in the UHPC was 25% to increase mechanical properties and reduce shrinkage; (b) at steel fiber content of 2%, the optimal plastic viscosity of the suspending mortar was 53 ± 3 Pa·s to secure favorable fiber distribution and enhance flexural properties of the UHPC; (c) through use of hybrid steel fibers, the flexural strength, tensile strength, and autogenous shrinkage of UHPC can increase by up to 20%, 25%, and reduced by 40%, respectively; (d) adding nanomaterials at a volume fraction of 0.3% increased the tensile strength and energy absorption capacity of the UHPC by 55% and 185%, respectively. In the end, novel applications of the developed reinforced and non-reinforced UHPC-FRP systems were explored for various applications"--Abstract, page iii.

Advisor(s)

Khayat, Kamal
Myers, John

Committee Member(s)

Khayat, Kamal
Myers, John
Yan, Guirong Grace
Kumar, Aditya
Chandrashekhara, K.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering

Sponsor(s)

Missouri University of Science and Technology. RE-CAST Tier-1 University Transportation Center

Comments

Financial support from the RE-CAST University Transportation Center at Missouri University of S&T under grant No. DTRT13-G-UTC45.

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2017

Pagination

xx, 249 pages

Note about bibliography

Includes bibliographic references (pages 230-248).

Rights

© 2017 Weina Meng, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11178

Electronic OCLC #

1003043222

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