The effect of polymers on the properties of textile-reinforced composites;Is it an adhesion or friction effect ?

Moshe Puterman 2Harald Schorn 3Michael Raupach 1

1. Aachen University of Technology - Institute for Building Research (IBAC), Schinkelstr. 3, Aachen D 52056, Germany
2. National Building Research Institute, Technion Israel Institute of Technology (NBRI), Technion City, Hajfa 32000, Israel
3. University of Dresden, Germany

Abstract

Glass fiber textiles, as well as textiles of other types, can be used as reinforcement for concrete elements. The reinforcing mash consist of woven rovings, each containing large amounts of fine fibers. However, the coarse cementitious binder does not penetrate very efficiently the inner parts of the roving and only the external filaments of each roving are in good close contact with the cementitious matrix.

The result is that only a small portion of the embedded filaments are the load bearing phase, whereas many (if not most) of the filaments are not contributing to the development of the expected mechanical properties.

It was the aim of this work to "activate" the inner parts of the roving by impregnation of polymers, in the form of aqueous nano-emulsions, into the textile. The main aim of te polymer addition was to improve the contact between the roving and the matrix, as well as bonding between the filaments themselves. Two types of polymers were used for this purpose:

- Film-forming, rubbery polymers

- non-film-forming, glassy polymers

both were tested in the wet and cured state.

The results, as presented by the flexure behaviour of the composite and pull-out properties of a single roving, suggest that the impregnated polymers have a substantial effect on the mechanical properties of the composite, with the non-film-former having a better contribution on the load bearing capacity of the system.

The results raise the interesting question: what is the main effect of the added polymer phase among the filaments: is it mainly an adhesion effect or a friction effect ?

 

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Presentation: oral at E-MRS Fall Meeting 2005, Symposium G, by Moshe Puterman
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-06-07 07:06
Revised:   2009-06-07 00:44