The results of 45 slant shear load carrying capacity of PCC substrate
and GPM or RM are shown in Fig. 3. The shear bond
strengths increased with the increased PC content and NaOH concentration.
The noticeable increase in shear bond strength was due
to the increase in the reaction products. This is in line with the previous
report [25]on the improved strength of fly ash based
geopolymers with increased calcium content which the additional
C–S–H and C–A–S–H gel co-existed with N–A–S–H gel of GPM. The
increase in reaction products at the interface transition zone
between PCC substrate and GPM enhanced the strength at contact