A Study of the internal defects of Terrazzo and Engraved construction materials using direct film neutron radiography technique

Neutron radiography technique has been utilized in the work for studying internal defects of various types of construction materials through optical density measurements of the samples. two kinds of locally developed construction materials have been used as samples in the experiment. they are terrazzo and engraved construction materials. tangential neutron radiography facility of 3 mw triga mark-research reactor is used here to find out the internal defects of the samples. from the observation of neutron radiographic images of the samples and variation of optical density at different positions,it revealed that the associated composites of terrazzo construction material are uniformly distributed. no voids or any inclusions in the materials have been observed in the radiograph. the neutron radiographic image of engraved construction material shows that the optical density values at different reference positions are different. the density at the central position of the image is different from its neighboring reference positions. moreover,some voids are observed in the neutron radiograph of the material. this confirms that in this material the associated composites are not uniformly mixed and distributed during its fabrication. so,the fabrication of this construction material is relatively faulty. this faulty material may have several bad impacts while it is used as a construction material. it can absorb rainwater and thus may be damaged. due to its structural disorder,its strength is deteriorated and may be damaged easily from even a very minor environmental turmoil. © pakistan academy of sciences.