Effect of moisture on tuff stone degradation

Author(s): Author(s): Author(s): Barbara Lubelli, Timo G. Nijland
Paper category: Proceedings
Book title: Proceedings on International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference segment on Moisture in Materials and Structures
Editor(s): Kurt Kielsgaard Hansen, Carsten Rode and Lars-Olof Nilsson
ISBN: 978-2-35158-178-0
e-ISBN: 978-2-35158-179-7
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 100 - 109
Total Pages: 10
Language : English

Abstract: Tuff stone elements with a large length/width ratio often suffer damage in the form of cracks parallel to the surface and spalling of the outer layer. The response of tuff to moisture might be a reason for this behaviour. This research aimed at verifying if differential dilation between parts with different moisture content (as outer and inner part of partially encased mullion) can lead to damage.
The effect of moisture on the degradation of Ettringen and Weibern tuff from the Eifel, Germany, has been investigated. A purpose-made weathering test was carried out to simulate the wetting-drying process. Despite no cracks developed during the test, existing cracks widened up and the flexural tensile strength of both materials decreased. The moisture transport properties their porosity and pore size of the stones were determined. Ettringen tuff has a considerable amount of very fine porosity, resulting in slow moisture transport and significant hygroscopic adsorption. Both tuff stones have an extreme hydric dilation. Environmental X-ray diffraction analyses showed that Ettringen tuff undergoes (reversible) mineralogic changes when subjected to RH cycles, whereas this does not occur for Weibern. The results support the hypothesis that moisture gradients in tuff elements may enhance decay in this stone.

Online publication : 2016
Publication type : full_text
Public price (Euros) : 0.00