Prompt gamma analysis of fly ash, silica fume and Superpozz blended cement concrete specimen

• Published in: Applied radiation and isotopes 2009-09, Vol.67 (9), p.1707-1710
• Main Authors: Naqvi, A.A., Garwan, M.A., Maslehuddin, M., Nagadi, M.M., Al-Amoudi, O.S.B., Khateeb-ur-Rehman, Raashid, M.
• Format: Article
• Language: English
• Subjects: 2.8 MeV neutrons based PGNAA setup; Elemental analysis; Fly ash; Monte Carlo simulations; PGNAA technique; Superpozz cement concrete samples
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2009.03.094

Preventive measures against corrosion of reinforcing steel require making the concrete dense by adding pozzolanic materials, such as fly ash, silica fume, Superpozz, blast furnace slag, etc. to Portland cement. In order to obtain the desired strength and durability of concrete, it is desirable to monitor the concentration of the pozzolan in the blended cement concrete. Addition of pozzolan to blended cement changes the overall concentration of calcium and silicon in the blended cement concrete. The resulting variation in calcium and silicon gamma-ray yield ratio from blended cement concrete has found to have an inverse correlation with concentration of fly ash, silica fume, Superpozz, blast furnace slag in the blended cement concrete. For experimental verification of the correlation, intensities of calcium and silicon prompt gamma-ray due to capture of thermal neutrons in blended cement concrete samples containing 5–80% (by weight of cement) silica fume, fly ash and Superpozz were measured. The gamma-ray intensity ratio was measured from 6.42MeV gamma-rays from calcium and 4.94MeV gamma-ray from silicon. The experimentally measured values of calcium to silicon gamma-ray yield ratio in the fly ash, silica fume and Superpozz cement concrete specimens agree very well with the results of the Monte Carlo simulations.