Macro-defect free cements: A new approach

The in situ reticulation of the water-soluble polymer used to obtain macrodefect free cements is proposed as a way to minimize the shortening of the mechanical properties at high relative humidity. The polymer is used in solution, instead of in bulk. Data obtained with poly(vinyl alcohol) (PVA) and sodium silicate shows that PVA is insolubilized in the presence of this reticulation agent. In the presence of cement, the effect is enhanced. Micro hardness values obtained for bulk-PVA/cement and in situ reticulated speci mens show that the reticulated specimens are not affected by humidity. Low w/c relations (0.2) and low polymer content (1%) are attainable. (C) 1998 Elsevier Science Ltd.28687788