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The mode of action of polypropylene fibres in high performance concrete at high temperatures



Title: The mode of action of polypropylene fibres in high performance concrete at high temperatures
Author(s): K. Pistol, F. Weise, B. Meng and U. Schneider
Paper category : conference
Book title: 2nd International RILEM Workshop on Concrete Spalling due to Fire Exposure
Editor(s): E.A.B. Koenders and F. Dehn
ISBN: 978-2-35158-118-6
e-ISBN: 978-2-35158-119-3
Publisher: RILEM Publications SARL
Publication year: 2011
Pages: 289 - 296
Total Pages: 8
Nb references: 10
Language: English


Abstract: It has been shown in fire tests that polypropylene fibres reduce or avoid explosive spalling of high performance concrete. In the critical temperature range up to 300 °C the permeability of HPC increases by using polypropylene fibre. Due to this the water vapour, which is the main reason for explosive spalling, can escape. There exist different theories in the literature concerning the micro structural mechanisms, which cause an increase in the permeability.
Within the framework of an internal research project at BAM an innovative methodology was developed for experimental verifying of existing theories and to get new insights into this problem. The methodology used is unique and has been undertaken here for the first time.
This consists of the combination of acoustic emission and ultrasonic measurement during temperature loading and the non-destructive micro structural analysis of cooled down samples with the aid of micro X-ray computed tomography. For the validation of the nondestructive test methods scanning electron microscopic images of prepared samples were undertaken. The results show that due to the thermal decomposition of the polypropylene fibres micro canals emerge. These are connected due to a simultaneous micro cack formation.


Online publication: 2012-01-17
Publication type : full_text
Public price (Euros): 0.00