Computers and Concrete

Techno-Press (테크노프레스)
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Thermal stress and pore pressure development in microwave heated concrete

  • Akbarnezhad, A. (Department of Civil Engineering, National University of Singapore) ;
  • Ong, K.C.G. (Department of Civil Engineering, National University of Singapore)
  • Received : 2010.01.11
  • Accepted : 2010.08.11
  • Published : 2011.08.25
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Abstract

Most previous studies have generally overlooked the contribution of thermal stresses generated within the concrete mass when subjected to microwave heating and reported on pore-pressure as being the dominant cause of surface spalling. Also, the variation in electromagnetic properties of concrete and its effects on the microwave heating process have not been studied in detail. In this paper, finite element modeling is used to examine the simultaneous development of compressive thermal stresses and pore-pressure arising from the microwave heating of concrete. A modified Lambert's Law formulation is proposed to estimate the microwave power dissipation in the concrete mass. Moreover, the effects of frequency and concrete water content on the concrete heating rate and pattern are investigated. Results show high compressive stresses being generated especially in concrete with a high water content when heated by microwaves of higher frequencies. The results also reveal that the water content of concrete plays a crucial role in the microwave heating process.

Keywords

References

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