*3.5.1 EDAX analysis*

The elemental composition of D20, D40, D60, D80 and D100 specimens are shown in **Figures 13**–**17** which show the presence of Ca, Si, Al confirming the formation of geopolymeric gel as well the process of geopolymerisation. The presence of calcium in geopolymer concrete indicates that the setting time fastens during process. The rapid hardening process through solidification of gel frame work is found to be contributed by C-A-S-H gel. This would facilititate ambient curing conditions.

Elemental Weights obtained from EDAX analysis are given in **Table 2**. It shall be observed that oxides are present in larger extent in all mixes. Binding property could be weekened by the presence of oxides. The decrease in strength initially (after D20) and subsequent increase in strength (from D80) may be due to the

**Figure 13.** *Elemental composition of G10A.*

**Figure 14.** *Elemental composition of G20A.*

### *Geopolymer Concrete under Ambient Curing DOI: http://dx.doi.org/10.5772/intechopen.97541*
