Affiliation:
1. Instituto Superior Técnico
2. Universidade de Coimbra
Abstract
This paper reports the results of a series of experiments carried out to investigate the effectiveness of newly hybrid polyethylene/polypropylene (PP/PE) fibres inclusion in the mechanical performance of cement matrices, with regard to fibres properties and content. The results indicate that, compared with plain cement matrix, the PP/PE fibre-reinforced cement matrices (FRC) revealed improvements on their mechanical performance. Increases of 37 ± 1% on compressive (40.2 MPa) and flexural strengths (8.1 MPa) were obtained for 24 mm fibre length composites containing a rather low fibre’s content (1 wt.%). These mechanical improvements were achieved after optimisation of the mortar workability by the addition of a superplasticizer. FRC mechanical behaviours also evidenced that despite the compressive strengths increasing with fibre length, a flexural strength effect is only noticeable for a 24 mm length fibre-reinforced composite and for fibres volume higher than 2.9 %. Morphological observations showed a strong interaction between fibres and cement matrix, evidenced a crack arrest role (bridge effect) on fibre/cement interfacial zone and revealed a typical multiple fracture cracking mechanism.
Publisher
Trans Tech Publications, Ltd.
Subject
Mechanical Engineering,Mechanics of Materials,Condensed Matter Physics,General Materials Science
Reference9 articles.
1. E. Garter, Industrially Interesting Approaches to Low-CO2, Cements, Cement and Concrete Research, 34 (2004) 1489-1498.
2. A. M. Brandt, Cement-based composites: Materials, Mechanical Properties and Performance, second ed., Taylor & Francis, New York, (2009).
3. B. Felekoglu, K. Tosun, B. Baradan, Effects of fibre type and matrix structure on the mechanical performance of self-compacting micro-concrete composites, Cement and Concrete Research 39 (2009) 1023-1032.
4. A. Bentur, S. Mindess, Fibre Reinforced Cementitious Composites, second ed., Taylor & Francis, New York, (2007).
5. European Standard EN 196-1, Methods of testing cement - Part 1: Determination of strength, European Committee for Stardization, Brussels, (2005).