Investigation of Mechanical Properties and Shrinkage of Ultra-High Performance Concrete: Influence of Steel Fiber Content and Shape


Use of steel fibers in ultra-high performance concrete (UHPC) plays a significant role in enhancing strength and toughness and restraining shrinkage. This paper investigates the effect of steel fiber content and shape on mechanical strength, toughness, and autogenous and drying shrinkage of UHPC. Three steel fiber shapes, including straight, corrugated, and hooked fibers, with volume fraction ranging from 0 to 3% were employed. Compressive, flexural, and fiber-matrix bond strengths were evaluated. A statistical quadratic model and the Composite Theory were employed to predict the flexural strength of UHPC. Test results indicated that the increase in fiber volume can enhance the compressive and flexural strengths of UHPC and reduce shrinkage. The optimum fiber content for strength and shrinkage was found at 2%, beyond which the strength was slightly increased and the shrinkage was slightly decreased. For a given fiber content, the use of hooked fibers was most efficient in improving fiber-matrix bond and flexural strengths and reducing shrinkage. The flexural strengths of UHPC made with various fiber contents and shapes can be predicted using the proposed quadratic model and the Composite Theory. The latter considers the primary parameters affecting performance, including bond strength, matrix properties, and fiber characteristics. Finally, several models were used to simulate autogenous shrinkage behavior of UHPC and optimal models were found.


Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Center for Research in Energy and Environment (CREE)


The authors gratefully acknowledge the financial support from the Ministry of Science and Technology under Project No. 2018YFC0705400 and National Science Foundation of China under Project No. U1305243 , as well as the Energy Consortium Research Center of Missouri S&T under grant No. SMR-1406-09.

Keywords and Phrases

Ceramic-matrix composites (CMCs); Fiber-matrix bond; Fibers; Mechanical properties

International Standard Serial Number (ISSN)

1359-8368; 1879-1069

Document Type

Article - Journal

Document Version


File Type





© 2019 Elsevier Ltd, All rights reserved.

Publication Date

01 Oct 2019