Béton de résine polyester application au domaine du génie civil: Fid-Bau Portal

Béton de résine polyester application au domaine du génie civil

Prin, D. / Cubaud, J. C.

Résumé Cette étude contribue à la mise au point d'un matériau nouveau: le béton de résine polyester, et à son utilisation, dans la réalisation d'une structure en voile mince autoportante. Quelques données bibliographiques sur les liants et les bétons de résines synthétiques conduisent au choix des résines polyesters en raison de leurs performances et de leur prix. La mise au point du matériau béton de résine polyester est entreprise: en premier lieu sa composition, sa technologie de fabrication, puis ses propriétés physico-chimiques, enfin ses propriétés mécaniques sous diverses sollicitations et en fonction de divers facteurs (étuvage, catalyse, agents anti-retrait, éprouvettes témions, température, temps). Ce matèriau est utilisé pour la réalisation d'une structure en voile mince de 12 m de portée. Aprè la construction d'un moule et la mise au point de la fabrication des pièces, des coques sont expérimentées en vraie grandeur: sous moment constant, sous charge répartie et sous un, gradient de température. Une comparaison du comportement expérimental et de schémas théoriques de calcul des structures est effectuée.

Summary The investigation reported here contributes to the development of a new material: a polyester polymer-concrete, and to its utilisation in the manufacturing of a thin structure. The literature on binders and on synthetic polymer-concrete shows that these products, may replace some of the hydraulic concretes, which frequently need electric or chemical protection. The epoxy and polyester binders are the ones with the most interesting properties, but because of the high cost of the epoxy binders, only polyester resins were used in the research. To develop the polyester polymer-concrete its granular composition was considered. This permits to obtain with the lowest percentage of synthetic binder a concrete offering the best mechanical characteristics for manufacturing as well as for use. Anti-shrinkage agents are added to the binder to reduce the shrinkage during the hardening of concrete. The mechanical propeties are analysed when the material is subjected to different boundary conditions, in terms of drying, catalysis, anti-shrinkage agents, characteristics of test-tubes, temperature, time. The material when subjected to rapidly applied load is elastic. Its creep is not very pronounced even under static loading. Since the material is expensive the polymerconcrete is used only for small volumes. This fact made it advisable to conduct the testing on thin shells of double curvature (12 m span, 2m wide and 50 mm thick). The mould was made of a glass-fiber reinforced polyester. Three shells were cast and tested: one under constant moment, the second one subjected to a distributed load (applied by means of polyethylene pipes filled with water and set on the whole surface) and the third one subjected to several, variations of temperature. A comparison is made between the testing behaviour and theoretical results obtained using finite elements and theory of shells. The elements are all identical and are limited by two families of lines of normal and geodesic curvature. The material is considered to be elastic and isotropic.