Benefits of TiO2 photocatalyst on mechanical properties and nitrogen oxide removal of ultra-high-performance concrete. (24th May 2021)

• Record Type: Journal Article
• Authors: Choi, Hong-Joon; Park, Jung-Jun; Yoo, Doo-Yeol
• Is Part Of: Construction & building materials. Volume 285(2021)
• Publication Date: 2021-05-24
• Subjects: Ultra-high-performance concrete -- Titanium dioxide -- Mechanical property -- Nitrogen oxide -- Photocatalyst; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2021.122921
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Maximum bond strength of 15 MPa is achieved for the straight steel fiber in UHPC with 50% TiO2 powder. Tensile performance of UHPFRC is enhanced by adding the TiO2 powder up to 75%. Energy absorption capacity increases as much as 78% by replacing 75% filler to the TiO2 powder. NO removal capability of UHPC increases with the TiO2 replacement ratio. About 7.7 times higher NO removal capacity in UHPC is achievable using the TiO2 powder. Abstract: This study aims to develop a novel type of ultra-high-performance fiber-reinforced concrete (UHPFRC) with excellent mechanical properties and nitrogen oxide (NOx ) removal capability. To achieve this, an inert filler, silica flour, was replaced with titanium dioxide (TiO2 ), which is known as a photocatalyst. The test results indicated that the average bond strength of a straight steel fiber embedded in ultra-high-performance concrete (UHPC) increased by replacing the silica flour with TiO2 powder up to 75% in general. Approximately 53% and 63% higher bond strengths and pullout energies, respectively, were thus achieved at 50% replacement rate. The tensile properties of UHPFRC were improved by TiO2, and its tensile strength slightly increased, while the strain capacity and g-value substantially increased. The energy absorbing capacity increased by as much as 78% due to the addition of TiO2 powder. Furthermore, the plain sample exhibited almost zero NOx removal efficiency, but increased with the replacement ratio of TiO2 powder up to 75%. The best NOx removal capability in the UHPC sample containing 75% TiO2 powder was thus 7.7 times higher than that of the plain sample.