Les bétons légers de résine, matériaux complémentaires des bétons légers hydrauliques

Résumé

Les lois d'enrobage par les résines sont totalement différentes pour un sable non poreux et pour un sable poreux. La maniabilitédu sable non poreux passe par un maximum pour une teneur en farine voisine de 24%, alors que celle des mortiers de sable léger augmente régulièrement avec son taux de farine. L'évolution des résistances à la compression simple des mortiers en fonction de leur teneour en farine est identique à celle de leur maniabilité.

La substitution du ciment par la résine permet, d'une part d'augmenter notablement les résistances mécaniques des bétons légers, d'autre part de diminuer la dispersion des mesures.

Summary

The performance of light weight concrete can be considerably improved by strengthening the aggregate. It is therefore interesting to carry out research on binders to fill the pores of aggregate, at the same time strengthening them. The authors have investigated the consequences of adding resin, comparing the workability of normal concrete and lightweight concrete.

This work reveals that the laws of coating with resin are quite different according to whether the sand is porous or non porous.

The workability of the former rises to a maximum for a 24% flour content (fine particles under 100μ) whereas the workability of mortars containing light-weight sand increases regularly with the flour content.

The increase in simple compressive strength of mortars according to their content in fine particles under 100 μ, is identical to the development in workability.

The improvement in the mechanical strengths of lightweight concrete depends on the degree of penetration of the resin into the sand pores. With very fluid matrixes it is possible to double the simple compressive strengths of various concretes.

Replacing the cement by resin doubles the ρ tensile strength/ρ compressive strength and also considerably reduces dispersion in measurement results.

It is thereby possible to define a nominal tensile strength which should make reinforced concrete design more simple.