Time:10:00,October 28, 2019
Venue: 441 conference room, School of materials science and engineering, Jiading Campus
Topic：The role of moisture in fire spalling of concrete
Leo Pel is an Associate Professor in the group transport in Permeable Media at the Department of Applied Physics, Eindhoven University of Technology (TU/e). He obtained his MSc in Applied Physics and received his PhD from the Department of Architecture, Building and Planningat TU/e for his thesis ‘Moisture transport in porous building materials’ in 1994. Following this, he worked as a Postdoctoral Researcher on development of a measurement method to determine moisture transport processes in porous materials. In 2006, he was a Visiting Researcher at the J. Paul Getty Museum and in 2008 he was a Visiting Fellow at Princeton University at the group of George Scherer. He is involved in various national and international projects focusing on understanding the durability of porous materials. In addition, he has taken part in various EU programs focusing on the conservation of our cultural heritage.
The question how concrete responds to a fire is one of the main questions in fire safety. During a fire, a building material can suddenly be heated up to temperatures well above 1000℃. At temperatures above 100℃ water inside the pores will start to boil. Simultaneously, in concrete, but also for example in gypsum, chemically bound water will be released by dehydration of the porous matrix. If the concrete has a low permeability, the vapour pressure inside will increase which can give rise to a sudden (explosive) failure of a material. Numerous heat and mass transfer models have been used to predict the moisture transport and its consequences on the strength and permeability of the concrete. However, these models are only of use if they can be validated. By using NMR we can get direct insight into the processes taking place and hence give as a tool to develop a simple model to determine the pressure build up. These measurements gave the first quantitative proof for the build-up of a moisture peak due to the vapour pressure build-up, which will be explained.