Combined NMR moisture, temperature and pressure measurements during heating

Abstract

Abstract.For model validation, quantitative measurements of the evolution of moisture, temperature, and pressure distributions in time are needed. For this purpose, we have developed an NMR setup to measure the moisture transport in heated building materials. The measured combined moisture content and temperature profiles give a unique insight in the moisture transport and dehydration kinetics inside concrete during fire. These measurements give the first quantitative proof for the build-up of a moisture peak due to the vapor pressure build-up. In this study we have also combined for the first time the measurement of the moisture and temperature profiles with the measurement of the pressure at one position, which show that the pressure build up is directly related to the moisture profiles.

Real-time measurements of temperature, pressure and moisture profiles in High-Performance Concrete exposed to high temperatures during neutron radiography imaging

“…For a better under-standing of spalling mechanisms, the results of pore pressure measure-ments should be directly compared with the moisture profiles inside the sample during thermal loading, which might in particular reveal the formation of moisture clogs. First attempts in this direction have been recently made by combining proton-spin relaxation NMR and pressure sensors [26].…”

Comparative life cycle assessment of composite structures incorporating uncertainty and global sensitivity analysis

“…The benchmark example is an excerpt from [32], where 1 m 3 of concrete production considers 400 kg of cement, 700 kg of sand, and 1200 kg of gravel. While for the other two scenarios, 1 m 3 of C40 concrete requires 350 kg of cement, 175 kg of water, 1194 kg of sand, and 614 kg of gravel [66]. A typical density of 7850 kg/m 3 is assigned to steel.…”