Fig. 7 shows the strength development in cement
treated soil-RAP mixture with various RAP contents
but with the same cement content. As the asphalt
content increases, the strength is lowered. The
presence of asphalt binder reduces the bonding
between RAP aggregate and soil. The asphalt binder
is detrimental to cement treated soils. The typical
strength development with curing time for cement
treated soil-RAP mixtures under 20%, 40% and 50%
of RAP content is shown in Figs. 8-10. The strength
development with curing time (days) in a natural
logarithmic scale can be expressed as a linear
variation. The strength ratio plots after normalization
are also shown in these figures. The normalized
relation is presented in Eq. (2).