Old Aswan Dam's masonry is a Portland cement mortar encapsulating large granite blocks with relatively weak bonds between blocks and the surrounding mortar. The masonry mortar in the original dam and the first heightening is composed of moderately hard light gray cement paste and coarse, evenly graded river sand containing granite, quartz, feldspar and Metaquartzite with minor amounts of mica. The quality and type of the masonry are nearly identical for these construction stages.
The mortar in the masonry of the second heightening is brownish, lean and dense with a moderate number of small to medium size pores that are not dispersed uniformly. Its masonry sand was finer and contained a large number of clay particles that were apparently beneficial to the consolidation of the masonry. However, the clay also increased water demand, which weakened the mechanical properties of the masonry. Chemical analyses showed that the water-cement ratio for this stage was 1.06, compared with 0.64 in the first heightening and 0.80 in the original dam. The sand-cement ratio remained about the same for all three construction stages, varying between 4.3 and 4.6.
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