Composite elements
A composite column is every vertical element composed by a number of rectangular members, one of which is considered to be a shear wall i.e. has a length to thickness ratio ≥ 4.
The simplest composite column is the one-member shear wall, like S1.
From a static point of view, S1 is composed by the shear wall T1 which has a section equal to 200/25.
From a reinforcement point of view, S1 is composed of the hidden (boundary) columns a0-1 and a1-0 with 25/45 section and the shear wall’s main body T1 with a section of 200/25 (including the length of the two boundary columns).
The S1 reinforcement consists of the clearly defined reinforcement of the three members that comprise the composite element, the two orthogonal columns and the shear wall’s main body.
In this specific example as well as in the others that follow, the horizontal rebars have been anchored by bending. It is obvious that any ther type of anchorage from those men- tioned in the previous chapter could have been chosen.
The ‘Γ’ section element G2-3 is a composite element comprised of two members.
From a static point of view, the G2-3 is composed of the column C2 which has a 25/70 section and the shear wall Sh3 with length and thickness equal to 150cm and 25cm respectively.
From a reinforcement point of view, the G2-3 consists of two boundary (hidden) columns: the 45/70/25/25 ‘Γ’ section column, the rectangular column a3-0 with a cross section of 25/45 and the shear wall’s main body Sh3 with a section equal to 150/25.
The reinforcement of G2-3 is composed of the clearly defined reinforcement of the three mem- bers that comprise the composite element, the two columns and the shear wall’s main body.
The ‘Γ’ section element G1-2 is a composite element that consists of two members.
From a static point of view, the G1-2 is composed of the shear wall Sh1 which has a 25/120 section and the shear wall Sh2 with length and thickness equal to 150cm and 25cm respec- tively.
From a reinforcement point of view, the G1-2 consists of three boundary (hidden) columns: the 45/45/25/25 ‘Γ’ section column a1-2, the rectangular column a1-0 with a cross section of 25/45, the 45/25 rectangular column a2-0 and the shear walls’ main bodies Sh1 and Sh2 with sections equal to 25/120 and 150/25 respectively.
The reinforcement of G1-2 consists of the clearly defined reinforcement of the five members that comprise the composite element, the three columns and the two shear wall main bodies.
Note:
The columns a 2-4 and a 2-5 could have been constructed as a single ‘Z’ section column.
