Projects / Programmes source: ARIS

The influence of fillers on mechanical properties of fibre-cement composites

Research activity

Code Science Field Subfield
2.04.01  Engineering sciences and technologies  Materials science and technology  Inorganic nonmetallic materials 

Code Science Field
T150  Technological sciences  Material technology 
T153  Technological sciences  Ceramic materials and powders 
T152  Technological sciences  Composite materials 
fibre-cement composites, pozzolans, strength, toughness
Evaluation (rules)
source: COBISS
Researchers (7)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  11142  PhD Milan Ambrožič  Materials science and technology  Researcher  2007 - 2009  258 
2.  17165  PhD Aleš Dakskobler  Materials science and technology  Researcher  2007 - 2009  156 
3.  03477  PhD Tomaž Kosmač  Materials science and technology  Researcher  2007 - 2009  505 
4.  17100  PhD Kristoffer Krnel  Materials science and technology  Head  2007 - 2009  188 
5.  09861  Jerneja Strupi-Šuput  Civil engineering  Technical associate  2009  134 
6.  11992  PhD Franc Švegl  Chemistry  Researcher  2007 - 2009  225 
7.  13550  PhD Krunoslav Vidović  Materials science and technology  Researcher  2007 - 2009  25 
Organisations (2)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0106  Jožef Stefan Institute  Ljubljana  5051606000  87,279 
2.  1502  Slovenian National Building and Civil Engineering Institute  Ljubljana  5866324000  10,103 
The fibre-cement composite (FCC) is a composite material that consists of hydrated Portland cement as a matrix, free water, air, small amounts of additives (fillers, pigments, etc.), and different kinds of natural or synthetic reinforcing fibres. In the company Esal d.o.o. Anhovo corrugated roofing sheets made of FCC with polyvinyl-alcohol (PVA) fibres are produced by the Hatzschek wet winding procedure. One of the fillers used in the serial production is silica fume. The addition of silica fume has two aspects: 1) it improves the rheological properties of wet sheets and enables their forming into a corrugated shape, 2) it increases the bending strength of the composites because of its influences on the chemical reactions during the cement hydration, while it decreases the fracture toughness of the sheets. Because of the problems with the recent silica fume supply an appropriate alternative material needs to be found, which would retain the good rheological properties of the wet sheets and also the final bending strength of the sheets, but would at the same time improve their fracture toughness. Therefore, the primary task of the proposed applicative investigation is to explore the influence of the filler type and concentrate on 1) on the rheological properties of fresh composites that are relevant for the shaping of the products, 2) on the bending strength and fracture toughness of hard FCC materials/products. Since some of the measured mechanical quantities and the quantities derived and calculated from the latter obey the Weibull statistics, the free parameters of this statistics can be determined, which is a new approach in the characterization of such materials/products.
Significance for science
The results of the research project already gave us new findings about the influence of various fillers, such as silica fume, metakaolin, fly ash and polimeric aditives, on the process of the fibre-cement-composite preparation (rheology of wet materials), on their microstructure and the resulting mechanical properties. Of special importance is the investigation of the interface between the cement matrix and the fibres in the composite and their connection to the fracture toughness of the composites since according to the literature this area has still not been comprehensively explored. In regard to the vast investigations of the mechanical properties of cement composites and other construction materials this research contributed some important statements, especially about the Weibull statistical distribution of the measured values of various mechanical quantities, such as the bending strength of roofing sheets.
Significance for the country
Civil engineering is one of the most important economic branches, therefore any simplification and price reduction in the production of civil engineering materials could have a significant economic effect. Due to improved properties of the products the increase of the competitive position can be expected, leading to production enlargement and opening of new employment positions. The improved fibre-cement composites will also be applicable elsewhere in the civil engineering leading to the products with higher additional tax values. The investigation has also an ecological relevance since it seeks for the ways of recycling wastes from Slovenian plants which otherwise burden the environment (fly ash and furnace slag).
Most important scientific results Annual report 2008, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2008, final report, complete report on dLib.si
Views history