Fourteen samples of marble were collected from different factories in Egypt. The samples were crushed, dried in controlled furnace for around twenty four hours, and then stored for five weeks in plastic Marinelli beakers. Concentrations and the U-and Th-bearing minerals were studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS).The gamma radiation of the samples was measured, employing high resolution γ-ray spectroscopy with an accumulating time for about 80000 sec. each. From the measured γ-ray spectra, activity concentrations were determined for marble samples 226 Ra (37. 6 ± 1.7 -100.54 ± 3.2 Bq/kg), All obtained results referred to the fact that all the concentrations were within the allowed limits to domestic use. Comparing the results in this work with those published by International Atomic Energy Agency and local and universal researches, it was found that these concentrations were within the allowed limits for agricultural and domestic uses.

This study investigated the effect of styrene-butadienerubber (SBR) latex/cement ratio as well as γ-irradiation dose on physicomechanical properties of cement mortar. Specimens were prepared with a different SBR/cement mass ratio of 2.5, 5, 10, 15, and 20. Two curing methods were used: wet cure and dry cure. The best specimens were irradiated to doses of 10, 30, and 50 kGy. The compressive strength, total porosity, and bulk density were studied. The result indicated that the compressive strength, total porosity, and the bulk densities of the composites decrease with increase in the polymer cement ratios. In addition, it was observed that the compressive strength of irradiated polymer-modified cement mortar composites was improved with the increase in the γ-irradiation dose, and the compressive strength of mix-cured samples was higher than those wet-cured samples at any irradiation dose. X-ray diffraction, thermogravimetric analysis, acid attack, and microstructure of SBR-modified cement mortar were characterized. J.

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