Interphase modification of alkali-resistant glass fibres and carbon fibres for textile reinforced concrete II: Water adsorption and composite interphases

The interaction between sizings and coatings is varied systematically resulting in different fibre surface modifications and interphase properties in cement matrix composites. The mechanical performance and the water adsorption of sized and coated alkali-resistant glass fibres (ARG) and the working capacity of the composites achieved are elucidated as a function of fibre diameter, sizing and coating content as well as their chemical formulations under special consideration of nanoclay concentrated within the interphase. Depending on the chemistry of the sizing and polymeric coating, respectively, the force–crack width curves together with hydration phase morphology derived from ESEM images of the concrete specimens are used to reveal composite interphases. Furthermore, the results achieved with nanodispersed polymeric coatings on glass fibres are transferred to carbon fibres and their concrete composites.