Title: Test Methods for Durability of Polymeric Fibers in Concrete and UV Light Exposure

Author(s): P. Balaguru and K. Slattum

Publication: Symposium Paper

Volume: 155

Issue:

Appears on pages(s): 115-136

Keywords: accelerated tests; cracking (fracturing); durability; electron microscopes; esters; fiber reinforced concretes; flexural tests; nylon fibers; polypropylene fibers; tensile strength; toughness; Materials Research

DOI: 10.14359/931

Date: 8/1/1995

Abstract:
Presents two test methods that can be used for evaluating durability of polymeric fibers subjected to alkaline environment present in concrete and UV light exposure. The test methods were used to evaluate three polymeric fibers: nylon, polypropylene, and polyester. Durability of the fibers in an alkaline environment was ascertained by measuring the flexural toughness of fiber reinforced concrete specimens that had been aged in lime saturated water maintained at 50 C. The UV light exposure test was conducted at a temperature of 65 C with intermittent water spray. The wet spray was used to simulate conditions in the field. Durability of the fibers was determined by measuring the retained tensile strength of the fibers after light exposure and by observing the surface characteristics of fibers under a microscope. The test results indicate that nylon and polypropylene fibers are durable in the alkaline environment present in concrete. The nylon fibers, which were light stabilized, were determined to be stable under UV light exposure. Polypropylene fibers deteriorated under UV light; the deterioration of the polypropylene single filament fibers was more rapid than for the fibrillated fibers. Hence, these fibers should not be used in applications in which the fiber contribution is needed at cracked-exposed sections.