Hard and Soft: Toughening Concrete by Impregnation with Functional Elastomers

Abstract:

Toughening is a concept frequently used in brittle materials in order to prevent premature failure. For concrete, toughening is almost exclusively achieved by pre-stressing, i.e. by creating residual stresses that force cracks to close. However, this can only be accomplished with certain element geometries and is particularly unsuitable for thin specimens.An alternative method of toughening is to deflect the crack or to absorb the crack tip by means of a suitable material, in particular viscoelastic polymers. In the present study, the concrete samples are transformed into hybrid inorganic/organic composites, in which the organic phase exerts the crack-stopping properties. To do so, the pore system is filled with a mixture of methyl methacrylate and 2-hydroxyethyl methacrylate, which is then polymerised to form a functional copolymer. Witha 1:1 ratio of the two monomers, a 4.5-fold increase in flexural strength and 2.3-fold increase in bending modulus was observed compared to the reference concrete. It is assumed that the additional increase compared to concrete impregnated with polymers not containing 2-hydroxyethyl methacrylate is the direct consequence of the interfacial interaction provided by the presence of pendant hydroxyethyl groups in the polymer.

• Periodical: Advanced Materials Research (Volume 1129)
• Pages: 438-444
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1129.438
• Online since: November 2015
• Authors: Oliver Weichold, Moshe Puterman
• Keywords: Mechanical Behaviour, Polymer Composite, Polymer-Impregnated Concrete, Radical Polymerisation

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