Thermal and mechanical evaluation of ultra-high performance fiber-reinforced concrete and conventional concrete subjected to high temperatures. (November 2020)

• Record Type: Journal Article
• Authors: Ashkezari, Ghasem Dehghani; Razmara, Mehrdad
• Is Part Of: Journal of building engineering. Volume 32(2021)
• Publication Date: 2020-11
• Subjects: Ultra-high performance fiber-reinforced concrete -- Thermal expansion coefficient -- Residual compressive strength -- Weight loss -- High temperatures -- Splitting tensile strength; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2020.101621
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: One of the most notable breakthroughs in concrete technology was the development of ultra-high performance fiber-reinforced concrete. In this study, for evaluating conventional concrete (CC) and ultra-high performance fiber-reinforced concrete (UHPFRC) exposed to high temperatures, the coefficient of thermal expansion, weight loss, and residual compressive strength were investigated. Moreover, two different curing methods (non-heated and heated) and two different percentages of steel micro-fiber inclusion for samples were implemented. Afterward, the mechanical properties of CC and UHPFRC, including compressive, splitting tensile and flexural strength, and also modulus of elasticity were evaluated. The results indicated that the thermal expansion coefficient of UHPFRC was more than CC. In non-heated samples, the weight loss of the specimens with two percent fiber inclusion by volume fraction was more significant than the specimens with one percent fiber inclusion, and also for heated samples, the weight loss of UHPFRC samples was almost twice as much as CC sample. Also, the residual compressive strength in non-heated samples escalated and then declined by increasing temperature between 20-200 °C and 200–400 °C, respectively. The residual compressive strength of all the heated samples raised and then decreased by increasing temperature from ambient temperature to 300 °C and from 300 °C to 700 °C, respectively. Highlights: Coefficient of thermal expansion, weight loss and residual compressive strength of UHPFRCs and CC were investigated. Two different curing methods (non-heated and heated) and two different percentages of steel fiber content were implemented. Thermal behavior of ultra-high performance fiber-reinforced concrete and conventional concrete were compared. Mechanical properties were determined including compressive, flexural, splitting tensile strength and modulus of elasticity.