Accelerated ageing characteristics of glass-fibre reinforced cement made with new cementitious matrices

Glass-fibre reinforced cement composites have been made using new types of cement matrices and subjected to hot water immersion ageing regimes. The ma trices were characterised by pore solution expression and analysis, XRD and DTA/TGA. Composite specimens were subjected to direct tensile tests. The n ew matrices displayed substantially reduced pore solution alkalinity and ca lcium hydroxide precipitation when compared with ordinary Portland cement ( OPC), thus providing a less aggressive environment for the fibres. Mechanic al tests showed that the rate of degradation of composites made from the ne w matrices, when aged at 65 degrees C in water, was an order of magnitude l ower than that for OPC matrix composites. The validity of this type of acce lerated test is discussed. (C) 1999 Elsevier Science Ltd. All rights reserv ed.