Title: Significance of Microstructure of the Glass Fiber-Cement Paste Interfacial Zone in Long-Term Durability of GFRC Composites

Author(s): Mitsunori Kawamura and Shin-Ichi Igarashi

Publication: Symposium Paper

Volume: 126

Issue:

Appears on pages(s): 799-820

Keywords: durability; electron microscopes; glass fibers; interfacial zone; microstructures; mortars; reinforced concretes; tensile strength; Materials Research

DOI: 10.14359/2388

Date: 8/1/1991

Abstract:
The long-term durability of glass fiber reinforced (GFR) mortars and concretes manufactured by the premixing method was investigated. Microhardness measurements and the quantitative back-scattered electron image (BSE) analysis were made in the regions around glass fiber strands embedded in the cement paste. Changes of flexural strength and toughness in the GFR mortars with age were found to be related to the features of microstructure in the interfacial regions. The toughness of the GFR mortars decreased with age in response to the increase in microhardness at the immediate vicinity of strands and around 70 to 100 æm from the interface. The solidification in the regions around 70 to 100 æm from interface, as well as the formation of the hydration products in the spaces among the glass filaments, appear to relate to reduction in toughness in GFRC composites.