Assessment of the effects of chemical constituents of siliciclastic sedimentary sands on their mechanical behaviour

Detailed study has been conducted on the assessment of the effects of chemical constituents (silica and impurities) of siliciclastic sedimentary sands on their mechanical behaviour through geochemical analysis using scanning electron microscope equipped with electron dispersive spectrometer, one-dimensional compression characteristics using oedometer test data, particle breakage and particle shape analyses using grading and petrographic microscope. The samples are poorly graded in grading and predominantly quartz in mineralogy and silica in chemical composition. Alumina is the most significant impurity because it influences the compressibility and the particle breakage of the samples. This is followed by the calcium oxide, sulphur oxide, phosphorous oxide, iron oxide and magnesium oxide in that order. The impurities have the most influence on the particle breakage followed by the compressibility and then the particle shape. The silica content has the most significant influence on the particle breakage and it has weak effects on the compressibility and particle shape, which could be linked to closeness of the value obtained. It is interesting to observe the rotational effects of impurities and silica on the particle shape characteristics of siliciclastic sedimentary sands. Since the influences of impurities on the mechanical characteristics of the specimens have been found, the practitioners and users of this important material must consider the removal of impurities in these materials before putting them into use for different applications.