| Abstrakt: |
In this paper, computer tomography is employed to characterise porosity, which plays a critical role in determining the mechanical response of cementitious materials under thermal load. Hydrated OPC-53 specimens are analysed at meso- and microscales, while subjected to temperatures of 27, 100, 400, 500 and 800°C, using high-resolution computer tomography (HRCT) and microtomography. Using two- and three-dimensional image-processing techniques, the system of pores and pore network is analysed. As the temperatures increased from 27°C to 800°C, an 800% increase in the number of pores at mesoscale and a 1400% increase in the number of pores at microscale were observed from HRCT and microtomography data, respectively. The number of micropores surrounding the mesopores increases with temperature, thereby forming a pore network, which coalesces into a failure plane, causing deterioration in compressive strength. [ABSTRACT FROM AUTHOR] |
