Abstract
Water movement in porous cement-based materials is of great importance when studying their deterioration processes and durability. Many traditional methods based on mass changes, electricity or nuclear magnetic resonances are available for studying water transport in cement-based materials. In this research, an advanced technique i.e. thermal neutron radiography was utilized to achieve visualization and quantification of time dependent water movement including water penetration and moisture vapor in porous cement-based materials through theoretical analysis and experimental study. Because thermal neutrons experience a strong attenuation by hydrogen, neutron radiography exhibits high sensitivity to small amounts of water. A neutron transmission analysis for quantitative evaluation of raw radiographic measurements was developed and optimized based on point scattered functions (PScF). The determinations of the real time and space dependent water penetration into uncracked and cracked mortar samples, as well as the drying process have been presented in this paper. It is illustrated that thermal neutron radiography can be a useful research tool for visualization and quantification of water movement in porous building materials. The obtained results will help us to better understand deteriorating processes of cement-based materials and to find ways to improve their durability.
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References
Phillipson M C, Baker P H, Davies M, et al. Moisture measurement in building materials: an overview of current methods and new approaches. Build Serv Eng Res Technol, 2007, 28(4): 303–316
Roels S, Carmeliet J, Hens H, et al. A comparison of different techniques to quantify moisture content profiles in porous building materials. J Therm Envelope Build Sci, 2004, 27(4): 261–276
Gummerson R J, Hall C, Hoff W D, et al. Unsaturated water flow within porous materials observed by NMR imaging. Nature, 1979, 281(5726): 56–57
Heijden G H, Bijnen R M W, Pel L, et al. Moisture transport in heated concrete as studied by NMR and its consequences for fire spalling. Cem Concr Res, 2007, 27(6): 894–901
Prazak J, Lunp P. Capillary suction of autoclaved aerated concrete. In: Wittmann F H, eds. Advances in Autoclaved Aerated Concrete. Balkema, Rotterdam: Elsevier Scientific Publishing Company, 1992. 119–123
Quenard D, Sallee H. A gamma-ray spectrometer for measurement of the water diffusivity of cementitious materials. Mater Res Soc Symp Proc, 1989, 137: 165–169
Pleinert H, Sadouki H, Wittmann F H. Determination of moisture distributions in porous building materials by neutron transmission analysis. Mater Struct, 1998, 31(4): 218–224
Hassanein R, Lehmann E, Vontobel P. Methods of scattering corrections for quantitative neutron radiography. Nucl Instrum Meth A, 2005, 542(1–3): 353–360
Hassanein R, Meyer H O, Caiminati A, et al. Investigation of water imbibition in porous stone by thermal neutron radiography. J Phys D: Appl Phys, 2006, 39(19): 4284–4291
Masschaele B, Dierick M, Cnudde V, et al. High-speed thermal neutron tomography for the visualization of water repellents, consolidants and water uptake in sand and lime stones. Radiat Phys Chem, 2004, 71(3–4): 807–808
Ridgway C J, Gane P A C, Ei-Abd A E G, et al. Water absorption into construction materials: comparison of neutron radiography data with network absorption models. Transp Porous Media, 2006, 63(3): 503–525
Pugliesi R, Andrade M L G. Study of cracking in concrete by neutron radiography. Appl Radiat Isot, 1997, 48(3): 339–344
Zhang Peng, Wittmann F H, Zhao T J, et al. Observation of water penetration into water repellent and cracked cement-based materials by means of neutron radiography. Int J Restor Build Monum, 2009, 15(2): 91–100
De Beer F C, Strydoma W J, Grieselb E J. The drying process of concrete: a neutron radiography study. Appl Radiat Isot, 2004, 61(4): 617–623
Wu Y L, Hu H S, Zhang B P, et al. Penumbral imaging and numerical evaluation of large area source neutron imaging system. Sci China Ser E-Tech Sci, 2009, 52(9): 2567–2575
ASTM E 748-02. Standard Practices for Thermal Neutron Radiography of Materials. 2002
The neutron transmission radiography (NEUTRA) station at PSI. http://neutra.web.psi.ch/facility/index.html, 2009
Lehmann E, Kuhne G, Vontobel P, et al. The NEUTRA and NCR radiography stations at SINQ as user facilities for science and industry. In: Chirco P, eds. Proceedings of 7th World Conference of Neutron Radiography. Rome, Italy: Italian National Agency for New Technologies, 2002. 593–602
Rivers M. An IDL based tomography reconstruction package. http://cars.uchicago.edu/software/idl/tomography.html, 2008
Zhang P, Wittmann F H, Villmann B, et al. Moisture diffusion in and capillary suction of integral water repellent cement based materials. In: Clercq H D, Charola A E, eds. Proceedings of 5th International Conference on Water Repellent Treatment of Building Materials. Brussels, Belgium: Aedificatio Publishers, 2008. 273–286
Guo P, Wittmann F H, Zhao T. On the efficiency of surface impregnation of cracked concrete. Int J Restor Build Monum, 2008, 14(6): 425–434
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Zhang, P., Wittmann, F.H., Zhao, T. et al. Visualization and quantification of water movement in porous cement-based materials by real time thermal neutron radiography: Theoretical analysis and experimental study. Sci. China Technol. Sci. 53, 1198–1207 (2010). https://doi.org/10.1007/s11431-010-0115-3
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DOI: https://doi.org/10.1007/s11431-010-0115-3