49. Durability of glass fibres

Title: 49. Durability of glass fibres
Author(s): K. Kopecskó
Paper category : conference
Book title: 6th International RILEM Symposium on Fibre Reinforced Concretes
Editor(s): M. di Prisco, R. Felicetti and G.A. Plizzari
Print-ISBN: 2-912143-51-9
e-ISBN: 2912143748
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 583 - 592
Total Pages: 10
Nb references: 9
Language: English

Abstract: Main concern of glass fibre reinforced concrete (GFRC) is the durability of glass fibres in the alkaline environment. In present study the alkali resistant fibres themselves were kept in extreme alkaline environmental condition. Purpose of our accelerated aging test was to study the possible deterioration processes and the reasons of the bond capacity increase in addition to the decrease of strength and ductility followed by the embrittlement of fibres. Fibres were immersed either in saturated calcium-hydroxide solution or cement extract solution for 8 days at 70ºC, and in saturated calcium-hydroxide solution for 56 days at 70ºC, respectively. The latter exposure condition was so strong that it could not necessarily happen during the whole service life embedded in concrete. We observed that one type of the coatings debonded, then holes started to appear on the surface of fibres as parts of the deterioration process. The other type of coating did not debond, however, holes appeared in the coating. Crystals originating from the Ca(OH)2 agent penetrate into the fibre strand. Deterioration process may lead to forming CSH phases. These may contribute to the observed increase of bond capacity.

Online publication: 2004-08-30
Publication type : full_text
Public price (Euros): 0.00