Xue and Shinozuka (2013) have mentioned that the bonding
between the cement paste and the crumb rubber can be improved
by the addition of silica fumes in concrete, which is proven by the
increase in compressive strength of the rubberized silica fume
concrete. Nayef et al. (2010) explained that the use of 5% silica
fumes in rubberized concrete helps to minimize the loss in
compressive strength at elevated temperatures. At elevated temperature
of above 400 C, the compressive strength was similar to
that of control concrete.