PHYSICAL, MECHANICAL, AND RADIATION ATTENUATION CHARACTERISTICS OF HEAVY WEIGHT CONCRETE EXPOSED TO ELEVATED TEMPERATURES

Abstract

The present work is concerned with the efficiency of proposed heavy weight concrete as a shielding material in the fields of shallow ground disposal applicable for low and intermediate level radioactive wastes, and locations where x-rays or radiotherapy are provided.

The heat generated from the attenuation of gamma-ray affects the efficiency of the shield. In addition, accidents involving fires are probable during the concrete structure life. Therefore, the assessment of the effect of elevated temperatures on physical, mechanical and radiation attenuation characteristics of heavy weight concrete is also one of the present research work objectives.

To achieve these objectives, three types oflocal natural aggregates (iron ores) namely, magnetite, limonite, and hematite have been tested to determine their mineralogical, physical and mechanical characteristics, and hence their • suitability for use as coarse aggregate in heavy weight concrete. The advanced techniques of X-Ray Fluorescence, Neutron Activation, and natural radioactivity have been. used to determine the chemical composition of all concrete materials (including elements transforming into radioactive by. irradiation). Based on the performed tests, two types of heavy weight concrete . were manufactured using magnetite and limonite as coarse aggregates.

Cube specimens were prepared for measunng density and compressive strength at ages 14, 28, 56 and 730 days. Cylind�cal specimens were prepared

for the determination of the splitting tensile strength, . modulus of elasticity, permeability (by Autoclam) arid radiation attenuation efficiency. •