Low calcium FA (class F) used in this research was supplied by
Lafarge Malayan Cement Bhd, Malaysia. The particle size distribution
test was performed by Mastersizers Malvern Instruments and
the result is shown in Fig. 1. The physical properties of both FA and
POFA are given in Table 1. The oxide composition of the materials
as determined by XRF using PANalytical Axios mAX instrument is
provided in Table 2. The Si to Al molar ratios for FA and POFA were
recorded as 4.07 and 34.03, respectively. FA and POFA morphology
was studied by means of FESEM (CARL ZEISS-AURIGA 60) and the
images of both source materials used in the preparation of geopolymer
mortar are shown in Fig. 2. Mining sand with a maximum
particle size of 1.19 mm was used as fine aggregate.