Synergistic effect of combined fibers for spalling protection of concrete in fire

• Published in: Cement and concrete research Vol. 40; no. 10; pp. 1547 - 1554
• Main Authors: Heo, Young-Sun, Sanjayan, Jay G., Han, Cheon-Goo, Han, Min-Cheol
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2010; Elsevier
• Subjects: Applied sciences; Building technical equipments; Buildings; Buildings. Public works; Cements; Concrete (E); Concretes; Concretes. Mortars. Grouts; Exact sciences and technology; Fiber reinforcement (E); Fibers; Fibre reinforced concrete (including asbestos cement); Fire; Fire behavior of materials and structures; Fire protection; Fires; Materials; Mechanical properties (C); Nylons; Polypropylenes; Spalling; Synergistic effect; Workability (A); Concrete (E); Mechanical properties (C); Workability (A); Fiber reinforcement (E); Fire; Construction materials; Concrete mix design; Concrete workability; Mechanical properties; High temperature; Experimental study; Synergism; Deterioration; Fires; Fiber reinforced concrete; Reinforcement; Protection
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2010.06.011

This study demonstrates the synergistic effect of some particular combination of fibers that can provide significantly better spalling protection of concrete in a fire than single fiber by themselves at the same fiber content level. Various combinations of polypropylene, polyvinyl alcohol, cellulose and nylon fibers were investigated. Fire tests were conducted in accordance with ISO-834. The combination of nylon (9 mm length) and polypropylene (19 mm length) fibers found to provide the most optimum results. By combining these two fibers, the same level of spalling protection was achieved by three times less fiber content than the single type of 0.10% polypropylene fiber commonly prescribed. A “fiber effectiveness parameter” is proposed which is a function of total number of fibers per unit volume and length of fiber. This parameter is useful in providing quantitative explanations of various fiber additions and their spalling results in fire.