Abstract
The aim of this experimental work was to study the porous structure of Ultra-High-Performance Fibre-Reinforced Concretes (UH) made with different fibre volume contents (0%, 1%, 2%) under several curing conditions (laboratory environment, 20 °C, 60 °C, 90 °C), comparing the results with those recorded for ordinary, high strength and very high strength concretes. Scanning electron microscopy, mercury intrusion porosimetry, thermogravimetry, water absorption and oxygen permeability tests were carried out. The results showed a low portlandite content in UH (in the order of 75% lower than in concrete C50) and a low degree of hydration, but they rise with curing temperature. These concretes have a very fine porous structure, with a high concentration of pores on the nanoscale level, below 0.05 µm. Their porosity accessible to water is consequently around 7-fold lower than in conventional (C30), 6-fold lower than in high-strength (C50) and 4-fold lower than in very high-strength (C90) concretes. Their oxygen permeability is at least one order of magnitude lower than in C90, two orders of magnitude lower than in C50 and three orders of magnitude lower than in C30. The percentage of added steel fibre does not affect the UH porous structure.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
