CHEMICAL-STABILITY OF INVISCID MELT-SPUN (IMS) FIBERS OF CALCIA-ALUMINA IN AQUEOUS-MEDIA

Vitreous fibers of CaO/Al2O3 (46.5/53.5 wt.%) prepared by inviscid mel t spinning (IMS) are shown to be susceptible to attack and eventual di ssolution by water. The attack proceeds with the formation of a hydrat e coating, which thickens with time at the expense of the underlying o xide fiber. With exposure to saturated lime water a limited initial at tack takes place, which then comes to a halt. A coating is formed that is thin, continuous and fine grained. The coating, composed chiefly o f Ca(OH)2 and a much smaller proportion of aluminum, appears to offer protection in the more corrosive aqueous environments. The strong basi c nature and favorable mechanical properties of these fibers make them especially of interest in the concrete industry, where the similarly strong basic nature of the Portland cement matrix suggests a degree of compatibility.