Comparison of the results from the 7, and 28 days samples shows that the compressive
strength, tensile strength and also flexure increases with SCBA up to 1.0% replacement (N1) and
then it decreases, although the results of 2.0% replacement (N4) is still higher than those of the
plain cement concrete (C0). It was shown that the use of 2.0% SCBA decreases the compressive
strength to a value which is near to the control concrete. This may be due to the fact that the