Microanalysis

The objective was to visually examine the structural and chemical composition of the soil-cement matrix of a prototype compressed and stabilized earth block (CSEB) material. To this end, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis were used.

The secondary electron detector of the system (model VEGA3, TESCAN) was used to analyze plate-type samples (i.e., models) with an approximate surface of 10 mm x 10 mm. The samples were mounted on aluminum stubs using sticky carbon tabs and then coated twice using a gold target (Desk II Sputter Coater, Denton Vacuum). Each sample's surface was analyzed throughout at least four different areas. The analysis process yielded 120 micrographs (magnification ranging from 50X to 25,000X) and 42 EDS analyses.

The microanalysis results indicated that the CSEB material has a consistent chemical composition through the matrix, and the Ca mapping provided visual evidence of the relatively uniform distribution of cement hydrates due to the stabilization.