Title: Durability Characteristics of Cellulose Fiber Reinforced Cement Composites

Author(s): P. Soroushian and S. Marikunte

Publication: Symposium Paper

Volume: 142

Issue:

Appears on pages(s): 73-90

Keywords: cements; composite materials; durability; fibers; strength; flexural strength; mechanical properties; reinforced concretes; toughness; weathering; wetting and drying tests; Materials Research

DOI: 10.14359/1182

Date: 1/1/1994

Abstract:
Relatively low-cost and energy-efficient materials with desirable short-term mechanical properties can be constructed using cellulose fibers as cement reinforcement. There are, however, concerns regarding the long-term performance of cellulose fiber reinforced cement composites; some cellulose fibers tend to disintegrate in the alkaline environment of cement. The growth of cement hydration products within the hollow cellulose fibers may also lead to excessive fiber-to-matrix bonding and brittle failure after exposure to natural weathering. This paper presents the results of an experimental study concerned with the long-term performance of cellulose fiber reinforced cement composites. Cellulose fiber reinforced cement composites were investigated, using accelerated weathering conditions representing repeated wetting and drying of materials in outside exposure conditions. The cement composites considered in this investigation incorporated 2 percent mass fractions of kraft pulp. Comprehensive replicated flexural test data were generated for various test ages at different wetting-drying cycles and were analyzed statistically. The analysis of variance and multiple comparison techniques were employed to derive reliable conclusions regarding the effect of accelerated wetting-drying cycles on flexural strength and toughness characteristics of cellulose fiber reinforced cement composites. The results generated in this study showed, at 95 percent level of confidence, that accelerated aging under repeated wetting-drying cycles had negligible effects on flexural strength, but led to reduced toughness and embrittlement of cellulose fiber reinforced cement composites.