EFFECT OF MOISTURE ON TUFF STONE DEGRADATION

Author(s): Barbara Lubelli, Timo G. Nijland
Paper category: Proceedings
Book title: Proceedings of the International RILEM Conference
Materials, Systems and Structures in Civil Engineering 2016
Segment on
Moisture in Materials and Structures
Editor(s): Kurt Kielsgaard Hansen, Carsten Rode and Lars-Olof Nilsson
Print-ISBN: 978-2-35158-230-5
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