Experimental Compressive Behavior and Numerical Modeling of Unconfined and Confined Ultra-High Performance Concrete
type: CreativeWork
description: Ultra-high performance concrete (UHPC) is commonly defined as a cementitious material, reinforced by fiber, which has compressive and sustained post-cracking tensile strength of more than 21.7 ksi (150 MPa) and 0.72 ksi (5 MPa), respectively. The outstanding mechanical behavior of UHPC is owed to its particular mixture. UHPC is a combination of Portland cement, silica fume, fine sand, ground quartz, high-range water reducer (superplasticizer), less than 0.25 water-to-cement ratio, and fibers (mostly steel fibers).Fibers play a crucial role in enhancement of the strength and ductility of UHPC in both tension and compression. Addition of fibers make the material to fail in a fairly ductile manner in compression (compared with material with no fiber) as well as providing ductility and energy absorption in tension. In the recent decades, UHPC has been used in some small-scale applications while it has the potential to be used in larger scales to build sustainable and seismic resistant structures. Currently, there is no comprehensive design guidelines or standards that can be used yet in the analysis and design of UHPC structures under various loading conditions. Thus, the overall goal of this doctoral study is to contribute towards future design guides by providing a better understanding of the compressive behavior of UHPC; at the material level through experimental testing of unconfined and confined cylinders, and at the structural level through numerical modeling.This study consists of three main parts. First, a series of uniaxial compression tests was conducted on more than 130 unconfined and confined UHPC cylinders with varied ratios of steel fibers and transverse reinforcements to evaluate linear and nonlinear behavior of UHPC in the pre- and post-peak regions. The individual and contributory confining effects of steel fibers and transverse reinforcement was quantitatively investigated and reported in terms of the full stress-strain curves, modulus of elasticity, s…
abstract: Ultra-high performance concrete (UHPC) is commonly defined as a cementitious material, reinforced by fiber, which has compressive and sustained post-cracking tensile strength of more than 21.7 ksi (150 MPa) and 0.72 ksi (5 MPa), respectively. The outstanding mechanical behavior of UHPC is owed to its particular mixture. UHPC is a combination of Portland cement, silica fume, fine sand, ground quartz, high-range water reducer (superplasticizer), less than 0.25 water-to-cement ratio, and fibers (mostly steel fibers).Fibers play a crucial role in enhancement of the strength and ductility of UHPC in both tension and compression. Addition of fibers make the material to fail in a fairly ductile manner in compression (compared with material with no fiber) as well as providing ductility and energy absorption in tension. In the recent decades, UHPC has been used in some small-scale applications while it has the potential to be used in larger scales to build sustainable and seismic resistant structures. Currently, there is no comprehensive design guidelines or standards that can be used yet in the analysis and design of UHPC structures under various loading conditions. Thus, the overall goal of this doctoral study is to contribute towards future design guides by providing a better understanding of the compressive behavior of UHPC; at the material level through experimental testing of unconfined and confined cylinders, and at the structural level through numerical modeling.This study consists of three main parts. First, a series of uniaxial compression tests was conducted on more than 130 unconfined and confined UHPC cylinders with varied ratios of steel fibers and transverse reinforcements to evaluate linear and nonlinear behavior of UHPC in the pre- and post-peak regions. The individual and contributory confining effects of steel fibers and transverse reinforcement was quantitatively investigated and reported in terms of the full stress-strain curves, modulus of elasticity, s…
author: Naeimi, Negar
keywords: Compression, Confinement, Finite Element Modeling, Seismic, Ultra High Performance Concrete
date published: 2020
date modified: 2026-07-27T21:47:58Z
provider: University of Nevada - Reno
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Nevada - Reno

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11714/7621