Effect of moderate temperatures on compressive strength of ultra-high-performance concrete: A microstructural analysis

Journal Article · Mon Feb 15 04:00:00 EST 2021 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2020.106303· OSTI ID:23206166

Suescum-Morales, David ^[1]; Ríos, José D.; De La Concha, Antonio Martínez-; Cifuentes, Héctor ^[2]

---

1. Construction Engineering Area, School of Engineering Sciences of Belmez, Universidad de Córdoba, Córdoba (Spain)
2. Department of Continuum Mechanics and Structural Analysis, School of Engineering, University of Seville (Spain)

Highlights: • All coarse aggregates and steel fibres were surrounded by the binder. • X-ray diffraction is useful for explaining the increase in compressive strength with increasing temperature. • Rosenhahnite and/or quartz Dauphiné-twinned phases improved the compressive strength. • Polypropylene fibres prevented spalling and preserved the compressive strength. • Concrete with steel and polypropylene fibres did not exhibit spalling at 300 °C. Concrete with two types of steel fibres and a polypropylene fibre prevented spalling and preserved the compressive strength at 300 °C, which makes these concretes suitable for long-term applications up to 300 °C, such as for steam collectors or thermal energy storage systems. The compressive strength behaviour of three types of ultra-high-performance fibre-reinforced concrete manufactured with the same matrix was investigated. For this purpose, a complete characterisation of all the raw materials and the three types of fibres used was performed. The morphology of all concrete mixtures at room temperature was analysed using scanning electron microscopy–energy-dispersive X-ray spectroscopy. From the results, it was ascertained that the steel fibres and coarse siliceous aggregates were not in contact (being separated by ≥3.41 μm) and were surrounded by the binder (of ≥1 μm in thickness) for all the mixtures studied. Rosenhahnite and/or quartz Dauphiné-twinned phases improved the compressive strength (as determined by X-ray diffraction).

• OSTI ID: 23206166
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 140; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPRESSION STRENGTH
ENERGY STORAGE SYSTEMS
FIBERS
MICROSTRUCTURE
MIXTURES
POLYPROPYLENE
QUARTZ
RAW MATERIALS
REINFORCED CONCRETE
SCANNING ELECTRON MICROSCOPY
STEELS
TEMPERATURE RANGE 0273-0400 K
THICKNESS
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY