A PLASTIC COMPOSITE BEAM OR PILLAR AND A METHOD FOR MANUFACTURING A PLASTIC COMPOSITE BEAM OR PILLAR

Abstract: The invention relates to a plastic composite beam or pillar (20) comprising a reinforced-plastic body (31) and steel reinforcements (30). The invention also relates to a method for manufacturing a steel-reinforced plastic composite beam or pillar, in which method the steel reinforcements (30) are placed in the beam or pillar (20) in connection with the manufacturing of the beam or pillar (20) by utilizing the pultrusion technique.

Description: A plastic composite beam or pillar and a method for manufacturing a plastic composite beam or pillar The invention relates to a plastic composite beam or pillar. Furthermore, the invention relates to a method for manufacturing a steel- reinforced plastic composite beam or pillar. In prior art, beams and pillars to be manufacrured of plastic composites are known, in which beams or pillars e.g. glass fiber or carbon fiber is used as a reinforcement. However, such known beams have not been sufficiently rigid for all applications. The object of the invention is to provide an essentially more slender and more rigid plastic composite beam or pillar than the known beams. For achieving the objects mentioned above and to be presented subsequenly, the plastic composite beam or pillar according to the invention is mainly characterized in that the beam or pillar comprises a reinforced-plastic body and steel reinforcements. The method according to the invention is mainly charaterized in that the steel reinforcements are placed in a beam or pillar in connection with the manufacturing of the beam or pillar by utilizing the pultrusion techique. A further embodiment of the method according to the invention is mainly characterized in that in the method, holes are formed in the plastic composite beam or pillar, in which holes are placed steel reinforcements, and that resin is injected into the holes after a possible bending for fixing the steel inforcements. Owing to these additional reinforcements, the beam according to the invention is essentially more rigid than a conventional beam. The cross-sectional area of the beam according to the invention can in certain applications be dimensioned smaller than that of a conventional beam, whereby material is saved and also material costs are reduced, since the rigidity of the beam increases owing to the additional reinforcements. The inner section of the beam or pillar can be filled with a poly-urethane, a cellular polystyrene or concrete filling for preventing the buckling of the plane¬ like surfaces of the cross-section during bending stresses. The invention also provides more applications for plastic composite beams or pillars due to their additional rigidity, and the steel parts make the fixing of profiles with screw joints possible. The solution according to the invention can also replace e.g. corresponding reinforced-concrete, wood or aluminium struc¬ tures. The invention is next described in more detail with reference to the figures of the accompanying drawing, in which Fig. 1 shows schematically a curved beam, Fig. 2 shows schematically a straight beam or pillar, Fig. 3 shows schematically a cross-section A-A of Fig. 1 and a cross-section D- D of Fig. 2, Fig. 4 shows schematically a cross-section D-D of Fig. 2 according to a further embodiment, and Fig. 5 shows a cross-section according to a further embodiment of the inventive beam, e.g a section D-D of Fig. 2. Fig. 1 shows a curved beam 10, whose ends are supported via supports 12. The curvature of the beam 10 is achieved by bending the beam into the curvature according to an arrow R, whereafter steel reinforcements 30 are placed in holes and fixed by means of resin injection. After the resin has set, the reinforcements 30 maintain the beam in the curved form. The beam 10 can be forced into the curved form e.g. by means of a draw bar 11, which can be removed after the resin has set, or it can be left as a part of the structure. In Fig. 2 is shown a straight beam or pillar 20, whose ends are supported via supports 12. The additional reinforcements are marked with dotted lines indicated by a reference number 30. In the schematic cross-section shown in Fig. 3 of a beam or pillar 10, 20, the reinforced-plastic structure of the beam 10,20 is indicated by a reference number 31 and the filler of the beam 10,20 is indicated by a reference number 32, which filler can comprise e.g. polyurethane or cellular polystyrene or concrete. The additional reinforcements according to the invention are marked with a reference number 30, and they are made e.g. of corrugated bar. In the embodiment of Fig. 3, the steel reinforcements are placed in the plastic composite beam or pillar 10,20 by using the injection technique in such a way that the plastic cxomposite beam or pillar 10, 20 comprises finished holes 33, in which the steel reinforcements 30 are placed, and the steel reinforcements 30 are fixed in place by injecting a resin 34 into the hole 33. In the inventive example of Fig. 4, a plastic composite beam or pillar 20 comprises a reinforced-plastic body and as an inner material 32 polyurethane or cellular polystyrene. The plastic composite beam or pillar 20 according to the embodiment shown in Fig. 4 is manufactured by utilizing the pultrusion technique in such a way that the steel reinforcements 30 are added to the plastic composite beam or pillar 20 in connection with the pultrusion. Fig. 5 shows a plastic composite beam or pillar 20, in which the steel reinforcements are in the form of steel plates 40. The remaining structure of the plastic composite beam or pillar 20 corresponds to that shown in the other figures in such a way that the reinforced-plastic body is indicated by the reference number 31 and the inner section of the beam, made of polyurethane or cellular polystyrene, in indicated by the reference number 32. The invention has above been described only with reference to its certain preferred embodiments. However, the intention is in no way to limit the invention to these examples, but many changes and modifications are possible within the inventive idea defined in the following patent claims.

Claims: Claims 1. A plastic composite beam or pillar, characterized in that the beam or pillar (10,20) comprises a reinforced-plastic body (31) and steel reinforcements (30,40). 2. A plastic composite beam or pillar according to Claim 1, characterized in that the beam or pillar comprises an inner section (32) made of polyurethane or cellular polystyrene or concrete. 3. A plastic composite beam or pillar according to Claim 1 or 2, characterized in that the steel reinforcement is a bar (30), e.g. a corrugated bar. 4. A plastic composite beam or pillar according to Claim 1 or 2, characterized in that the steel reinforcement is a steel plate (40). 5. A plastic composite beam or pillar according to any of the Claims 1-4, characterized in that the beam or pillar (10,20) comprising steel reinforcements (30,40) is manufactured with the pultrusion technique. 6. A plastic composite beam or pillar according to any of the Claims 1-4, characterized in that in the beam or pillar (10,20) are formed holes (33), in which the steel reinforcements (30,40) are fixed by utilizing the injection technique. 7. A plastic composite beam or pillar according to any of the Claims 1-6, characterized in that the steel reinforcements (30,40) are placed inside a body (31) made of reinforced plastic. 8. A method for manufacturing a steel-reinforced plastic composite beam or pillar, characterized in that the steel reinforcements (30,40) are placed in the beam or pillar (10,20) in connection with the manufacturing of the beam or pillar (10,20) by utilizing the pultrusion technique. 9. A method for manufacturing a steel-reinforced plastic composite beam or composite beam or pillar, in which holes are placed steel reinforcements (30,40), and that resin is injected into the holes (33) after a possible bending for fixing the steel inforcements (30,40).

Inventors: AHOPELTO ERKKI, KAERNAE TOIVO, PULKKINEN JORMA, SAARELA OLLI, AHOPELTO, ERKKI, KAERNAE, TOIVO, PULKKINEN, JORMA, SAARELA, OLLI
Applicants: NESTE OY
Application year: 1990
Main classification: E04C3
IPC codes: E04C3