Premium
Chemical and Microstructural Changes at Alkali‐Resistant Glass Fiber–Cement Interfaces
Author(s) -
Ylmaz Veyse T.,
Lachowski Eric E.,
Glasser Fred P.
Publication year - 1991
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1991.tb04301.x
Subject(s) - materials science , composite material , microstructure , fiber , glass fiber , portland cement , ultimate tensile strength , cement , composite number , crystallinity , synthetic fiber
Portland cement matrices have been reinforced by 5 wt% of “CemFIL 1′’alkali‐resistant glass fiber and isothermally wet cured for up to 1 yr at 20° and 55°C. Degradation of mechanical properties occurs as a consequence of chemical attack on the fibers. Various stages of the degradative process are followed by electron microscopy and analysis. The original composite microstructure is described in terms of a solid fiber reinforcing system. However, the fibers gradually become hollow, leaving a concentric shell of cement‐fiber reaction product which still gives a useful measure of reinforcement. These changes, together with fiber shortening arising from local impingement of Ca(OH) 2 crystals, give rise to what is termed a hollow cylinder reinforcement system. The hollow shell structures consist of gel and semicrystalline material; glass is absent or nearly so. The role of zirconia in stabilizing the hollow cylinder structures is described. It is considered that the microstructure developed at ∼20°C, while not as effective a reinforcement as solid fibers, still provides useful tensile reinforcement relative to plain paste matrices.