Test Study of Fracture Mechanical Properties of Reactive Powder Concrete with Additives

Yin, Zhi Gang

doi:10.4028/www.scientific.net/amr.904.3

Cited by 2 publications

(1 citation statement)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, previous studies (Yin, 2014;Deng and Feng, 2016;Peng et al, 2016) on the effects of fibers on UHPC, macroscopically, have considered that the role of fibers is to increase the tensile strength and toughness of the matrix. The mechanism behind the effects of fibers has not been studied separately, and the effects of the fiber distribution and geometric characteristics on the mechanical properties of UHPC have not been elucidated.…”

Section: Introductionmentioning

confidence: 99%

Ultra-High-Performance Concrete Crack Propagation Based on Fiber Random Distribution Model

Liang

Liu

et al. 2022

Front. Mater.

View full text Add to dashboard Cite

The tensile strength, crack behavior, and strain-hardening properties of ultra-high-performance concrete (UHPC) are mainly affected by the steel fibers distributed in the matrix. In this study, a mesoscopic model of UHPC was established using a numerical simulation method to study the effects of steel fibers on the crack propagation and tensile properties of UHPC. First, the exponential cohesive model was used to simulate the pull-out of a fiber embedded in a UHPC matrix. Then, the distribution and variation of the interfacial shear stress during the fiber pull-out process were obtained, and the UHPC fiber-pull-out load–displacement curve was obtained. Using the Monte Carlo method, a meso-scale finite element model of UHPC was established by modeling randomly distributed steel fibers in the UHPC matrix. After verification, the model was used to study the effects of fiber characteristics, interface strength, and matrix strength on the crack propagation path and tensile properties of UHPC. The results showed that the exponential cohesive constitutive model with a softening coefficient of –1 can effectively characterize the mechanical behavior of the interface between the steel fibers and matrix in UHPC. Affected by the random distribution of fibers, the main propagation mode of cracks in UHPC was that the cracks bypassed the fiber-dense area and extended to the fiber-sparse area, and the crack propagation path was mainly affected by the fiber distribution. The distribution of fibers significantly affected the tensile strength and peak strain of UHPC. When the fiber inclination angle was in the range of 15°–30°, the comprehensive tensile properties of UHPC were the best. With increasing fiber volume fraction and fiber length, UHPC gradually began to exhibit multi-cracking and strain hardening (when the fiber volume fraction was more than 2.5% or fiber length was more than 15.5 mm). The interface strength and matrix strength had little effect on the crack propagation path, but had significant effects on the tensile strength and toughness of the UHPC. The higher the strength of the UHPC matrix, the more fully the anti-cracking effect of the steel fiber that can be achieved.

show abstract

Section: Introductionmentioning

confidence: 99%