Pore water state in heated concrete
- Spalling of concrete structures is a serious issue for their safety. A better understanding of the pore water distribution and state during a fire is a prerequisite for numerical approaches to such problems.
Temperature-driven water transport in concrete consists of multiple phenomena, such as convection, diffusion, adsorption and dehydration. Distinguishing the different influences experimentally is difficult because typically they cannot be disentangled.
A common experimental setup approximates a one-dimensional flow, and places temperature and pressure gauges along the propagation direction. For direct information about the water content inside a sample, methods such as NMR or neuron radiography are necessary.
A multiphase model for the flow in porous media is presented, with dehydration and changes in the pore size distribution taken into consideration. NMR measurements for temperature-driven flow have been performed. The numerical and experimental results are comparedSpalling of concrete structures is a serious issue for their safety. A better understanding of the pore water distribution and state during a fire is a prerequisite for numerical approaches to such problems.
Temperature-driven water transport in concrete consists of multiple phenomena, such as convection, diffusion, adsorption and dehydration. Distinguishing the different influences experimentally is difficult because typically they cannot be disentangled.
A common experimental setup approximates a one-dimensional flow, and places temperature and pressure gauges along the propagation direction. For direct information about the water content inside a sample, methods such as NMR or neuron radiography are necessary.
A multiphase model for the flow in porous media is presented, with dehydration and changes in the pore size distribution taken into consideration. NMR measurements for temperature-driven flow have been performed. The numerical and experimental results are compared for water transport at temperatures below the critical point. Since both the finite-element model and the experiment allow the distinction between adsorbed, capillary and bulk water, a more fine-grained view of the pore water state is obtained.…