Journal Published Online: 28 March 2013
Volume 41, Issue 3

Effect of Steel Fibers and Thermal Cycles on Fracture Properties of Ultra-High-Performance Concrete



The advent of ultra-high-performance concrete (UHPC), a new generation of cementitious material having excellent material properties, has generated a great deal of interest in the field. In this study, the fracture properties of UHPC mixtures reinforced with steel fiber (fiber content varying from 0 to 6.2 % by weight) and subjected to thermal cycles were investigated to examine the effect of heat–cool cycles. The standard prism of 100 × 100 × 400 mm3 with a central notch was used in a three-point bend test to determine fracture properties that include critical stress-intensity factor (Kic), critical crack tip opening displacement (CTODc), energy release rate, and total fracture energy. All specimens were water-cured for 28 days. Two exposure conditions were used: a 6-month thermal cycling and a 6-month laboratory exposure for further self-curing. The thermal cycling comprised heating in an oven at 60°C for 2 days and then cooling them at room temperature for the next 2 days over a period of 6 months. Test results show that UHPC reinforced with 6.2 % steel fiber exhibited excellent fracture properties with significant ductility. Both thermal cycling and prolonged self-curing of water-cured UHPC specimens enhance fracture properties because of more complete hydration of cement in UHPC. This improvement in properties signals an additional advantage of water-cured UHPC for its application in hot climatic conditions.

Author Information

Hakeem, Ibrahim
King Fahd Univ. of Petroleum and Minerals, Dhahran, SA
Azad, Abul
King Fahd Univ. of Petroleum and Minerals, Dhahran, SA
Ahmad, Shamsad
King Fahd Univ. of Petroleum and Minerals, Dhahran, SA
Pages: 7
Price: $25.00
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Stock #: JTE20120182
ISSN: 0090-3973
DOI: 10.1520/JTE20120182