Water absorption of acid attacked specimens at 28, 56 and
84 days did not follow the trend of the control mix. When we
observe Figs. 6 and 7, the top layer of the concrete specimens with
0% crumb rubber was completely removed (100%) by the action of
sulphuric acid. In the case of the mix with 20% crumb rubber, less
than 100% top surface were attacked by acid. The rubber particles
and the cementitious layer surrounding the rubber particles were
unaffected by acid and have projected outwards by providing extra pockets to arrest the water. So the water absorption of rubberized
concrete was higher than the control mix concrete.