AGING OF WASTE PET FIBRES USED AS MICRO-REINFORCEMENT IN CEMENTITIOUS MATRICES

10th International Multidisciplinary Scientific GeoConference - SGEM2010, www.sgem.org, SGEM2010 Conference Proceedings/ ISBN 10: 954-91818-1-2, June 20-26, 2010, Vol. 2, 865-870 pp

ABSTRACT

The increasing amount of poly(ethylene terephthalate) (PET) waste is a worldwide
problem which has induced requirements for its recycling and reusing. PET fibres have
been used as a dispersed micro-reinforcement in a cementitious matrix. The microreinforcement
in the fibre reinforced concrete absorbs tensile strain and prevents
formation of microcracks originating from concrete shrinkage. The present work has
been aimed at studying the effects of aging PET fibres by alkali hydrolysis and
temperature cycles on the compressive and flexural strength of the PET-cement
composite. Using differential scanning calorimetry, infrared spectroscopy and water
vapour sorption, chemical changes of PET fibres after their degradation have been
characterized together with their effect on mechanical properties of the fibres and the
resulting PET-cement composite. It has been found that the flexural strength of the
composite has been increased by alkali hydrolysis of PET fibres in sodium hydroxide.

Keywords: cement composite, PET fibre, aging, mechanical testing