The Effect of Polypropylene and Steel Fibers on the Properties of Concrete at Normal and Elevated Temperatures—A Review

• Published in: Iranian journal of science and technology. Transactions of civil engineering 2022-06, Vol.46 (3), p.1805-1823
• Main Authors: Bhat, Muhammad Dilawar, Rehman, Mujeeb Ul, Shafi, Iflah, Parveen, Aasiya, Fayaz, Amir, Malik, Bashir Ahmad, Bashir, Fouzia
• Format: Article
• Language: English
• Subjects: Civil Engineering; Compressive strength; Concrete properties; Dosage; Engineering; Fibers; Heat resistance; High temperature; Impact resistance; Mechanical properties; Permeability; Polypropylene; Reinforced concrete; Reinforcing steels; Review Paper; Spalling; Steel; Steel fiber reinforced concretes; Steel fibers; Synthetic fibers; Tensile strength
• ISSN: 2228-6160; 2364-1843
• DOI: 10.1007/s40996-021-00751-3

Fibers are especially used to boost different characteristics of concrete and to make concrete efficient, wherever it lacks performance. This study was carried after addition of synthetic fibers namely Polypropylene fibers and Steel fibers and their respective effects on some important characteristics of concrete like mechanical properties, crack analysis, permeability, and spalling at ambient and raised temperatures. It was found that polypropylene enhances the mechanical properties and impact resistance of concrete. An optimum quantity of fiber enhances these properties, but if fiber dosage exceeds the optimum dosage, there is a certain decrement in properties. Although the optimum percentage obtained was different for different properties, but in general, all properties got enhanced if the addition of polypropylene was less than 2%. Polypropylene also increased the spalling resistance of concrete up to 600 °C, but beyond 600 °C, it reduces the effect of spalling and could not prevent it entirely. The inclusion of steel fibers to concrete showed a significant positive influence on the mechanical properties at high temperatures and increased the temperature at which spalling occurs up to a dosage of 1 – 1.5%, beyond 1.5%, compressive strength decreases. Between 20 and 700 °C, steel fiber reinforced concrete showed 40% more split tensile strength than normal concrete.