Results and Discussions
Table 2 shows the chemical composition of the soil sample, RHA and the
ordinary Portland cement by percentage weight composition. According to
Ola [16], if silica (SiO2) to
sesquioxide (Fe2O3 +
Al2O3) ratio of a given soil sample is
less than 1.33, the soil sample can be said to laterites, if it is
between 1.33 and 2.0, it can be said to be lateritic soil, and if it is
above 2.0, it is non-lateritic soil. The silica to sesquioxide ratio of
the soil sample is 1.28. It therefore means that the soil sample is
laterite soil.
Furthermore, RHA passes for pozzolanic materials. According to ASTM C618[25], a material can pass for a pozzolan if the
sum by addition of weight percentages of Fe2O3, Al2 O3 and
SiO2 equal at least 70%. Table 2, under RHA, the sum of
SiO2, Al2O3 and
Fe2O3, equals 86.88. This additive (RHA)
is a pozzolan. Also, Table 2 shows the elemental oxides in the ordinary
Portland cement used for this study. The constituents clearly shows that
the cement meets the stipulated standards as spelt out in the Nigerian
Standards NIS 367 [26] and NIS 368-2[27].
Table 2: Chemical Composition of Soil sample, RHA and Cement