Improvements in and relating to reinforced concrete structures and structural members

摘要

770,298. Floors; roofs; beams. STRUCTURAL CONCRETE COMPONENTS, Ltd., and SAINTY, C. L. Nov. 1, 1954 [March 2, 1954], No. 6057/54. Class 20(4) A structure, or a structural member such as a beam, for resisting bending loads, has the part 1 containing tension reinforcement 3 and lying below the neutral axis formed from light weight concrete adapted to carry a substantial proportion of the tension and such that the ratio between its modulus of rupture and its modulus of elasticity is substantially greater, e.g. from four to six times, than that of dense concrete, and the part 2 lying on the other side of the neutral axis formed from a denser concrete. As shown applied to a beam which may be laid side by side with similar beams to form a floor or roof, the concrete in part 1 comprises expanded clay aggregate and expanded vermiculite with which may be added mineral fibrous material or a binding emulsion to increase the tensile strength and the reinforcements 3 are as described in Specification 720,615. The part 2 is of normal concrete mixed with light reinforcement rods 4 to protect the beam during handling. In a modification the part 2 is of lightweight concrete of a denser type than that in part 1. The beams forming a floor or roof may be covered with a finishing screed which may be bonded to the beam as described in Specification 743,391 and in a further form this screed may form the part 2 of the structure the part 1 being formed by beams solely of lightweight concrete.