Neutron Absorption Properties of Geopolymeric Composite used Taftan Mountain Volcanic Ash

Subject Areas : journal of New Materials

Babak Hashemi ¹ , Roghayeh Amini ²

1 - Associate Prof.
2 - Materials Dept., Shiraz University

Received: 2019-04-10 Accepted : 2019-09-02 Published : 2019-10-23

Keywords: Boron Carbide, Boron Oxide, Geopolymer, Volcanic Ash, Neutron Absorber,

Abstract :

Neutron absorbers materials must have the ability to slow down the fast neutrons and absorb the thermal neutrons. In recent years, geopolymers have used as a replacement for cements and used to store nuclear waste. In this study, neutron absorption properties of geopolymer samples were investigated. In this regard, Taftan Mountain volcanic ash was used for synthesis of the samples. Sodium hydroxide and sodium silicate were used as alkaline activators. The samples were cured at 65°C for 24 hours and then kept at ambient temperature for seven days in order to geopolymerisation reactions were completely done. The fast neutrons were retarded by light elements such as hydrogen or carbon and boron absorb thermal neutrons In order to improve the absorption properties of the samples boron oxide and boron carbide (by 5-10 wt%) were added to them. The x-ray diffraction (XRD) and Fourier transformation spectroscopy (FTIR) were performed to investigate the phase and chemical bond, properties of the samples respectively. The compression strength and absorption properties of the samples were studied by compression and absorption tests. The XRD results confirmed the existence of geopolymer phases and the FTIR results showed the existence of a geopolymer network. The sample without any additive had maximum compressive strength 37.5 MPa. The absorption test results showed that the samples containing boron carbide had higher neutron absorption than the samples containing boron oxide due to existence of carbon in them.

References:

1.  Arthur Chilton, J. Kenneth Shultis, and Richard E. Faw. "Principles of radiation shielding." (1984).


2.  M. N. Nasrabadi and G. Baghban. "Neutron shielding design for 241Am–Be neutron source considering different sites to achieve maximum thermal and fast neutron flux using MCNPX code." Annals of Nuclear Energy Vol. 59, pp 47-52, 2013.


3. T. Nicholas "Measurement and detection of radiation" CRC press, 2010.


4. P. Duxs, J. L Provis, G. C. Lukey, A. Palomo and, J. S van Deventer "Geopolymer technology: the current state of the art"Journal of materials science, Vol. 42 no.9, pp 2917-2933, 2007.


5.  H. Djwantoro and B. Vijaya Rangan. "Development and properties of low-calcium fly ash-based geopolymer concrete." 2005.


6. J. Davidovits, "Geopolymer cement. A review" Geopolymer Institute, Technical papers, Vol.21, pp 1-11, 2013.


7. F. Pacheco-Torgal, "Introduction to handbook of alkali-activated cements, mortars and concretes" In Handbook of alkali-activated cements, mortars and concretes, pp.1-16, 2015.


8. P. Chindaprasirt and U. Rattanasak "Utilization of blended fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash in geopolymer" Waste Management, Vol. 30, no. 4 pp 667-672, 2010.


9. N. Ranjbar, M. Mehrali, A. Behnia, U. J. Alengaram, and M. Z. Jumaat, "Compressive strength and microstructural analysis of fly ash/palm oil fuel ash based geopolymer mortar" Materials & Design Vol. 59, pp 532-539, 2014.


10. Tchadjié, and D. Njopwouo "A comparative study of two methods to produce geopolymer composites from volcanic scoria and the role of structural water contained in the volcanic scoria on its reactivity" Ceramics International Vol.41, no. 10, pp 12568-12577, 2015.


11.  M. Mahdy, P. R. S. Speare, and A. H. Abdel-Reheem "Shielding properties of heavyweight, high strength concrete" In 2nd Material Specialty Conference of the Canadian Society for Civil Engineering, pp. 5-8, 2002.


12. D. Khale and R. Chaudhary,"Mechanism of geopolymerization and factors influencing its development: a review" Journal of materials science, Vol. 42, no. 3,  pp 729-746, 2007.