The average UCS strength for three
samples of treated soil for different curing times is
shown in Table 3 and Figure 2 indicating that the
UCS strength for all mixtures increased with curing
time. At 3 d, the control strength of SCM00 (only
OPC content) produced the greatest soil strength
and this decreased with an increase in the RHA
substitution content. At 28 d, some mixtures with
an RHA content (SCM10 to SCM30) had a higher
strength than SCM00, with SCM30 producing the
highest compressive strength whereas the SCM40
sample had the lowest. The proposed equations
for strength prediction with curing time had high
coefficients of determination and are presented in
Table 4.