The development of Sifcon for use in structural applications

• Main Author: Marrs, David Leonard
• Published: University of the West of Scotland 1998
• Subjects: 620.118; Slurry infiltrated fibre concrete
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245380

SIFCON was first reported in 1984 and showed excellent potential as a structural material. Applications, however, have been slow to emerge. The aim of this investigation was to simplify the production of SIFCON and to identify practical applications. A direct infiltration test was developedt o assessth e effect of materials and admixtures on the infiltration properties of cement based slurries. A slurry was designed which could infiltrate fibre beds containing up to 16 percent by volume of fibres without the aid of vibration. To achieve this, novel use was made of viscosity modifying admixtures in conjunction with superplasticisers. The mechanical properties of the SIFCON produced using the new slurry were investigated in terms of compression and flexure. It was found that, while the outstanding parameters, in terms of strength and ductility, associated with SIFCON were apparent, the resulting material was strongly anisotropic. The compressive modulus of elasticity was found to be significantly lower than would be expected for conventional concrete of similar strength. Pull-out tests showed that the bond performance was ductile for ribbed reinforcing bars embedded in SIFCON, however, the dependenceo n fibre orientation was highlighted. SIFCON sections were successfully incorporated into reinforced concrete beams and the production of these beams demonstrated the benefits of the self compacting technique. The results of third point loading tests highlighted problems relating to the modulus of rupture of SIFCON, and the difficulties faced when introducing it into reinforced concrete structures. It was also found that the use of SIFCON in horizontally cast beams was inefficient in the compression zone. It is expected that the advances made in the development of the production process will lead to increased acceptance of SIFCON and that new applications will emerge.