Advantages of steel-concrete composite column
The optimal location of the steel section
In CFT columns, due to the placement of the steel wall around the cross-section, where the bending and tensile stresses are more effective, it causes a significant increase in the stiffness and strength of the cross-section. In SRC columns, the location itself is a factor in the quick installation of the column.
High bending strength in beam-to-column connection in SRC composite columns
Due to the fact that the column and beam in this type of composite column are separated by reinforced concrete, the rotational stiffness increases due to the transfer of load between the beam and concrete in the connection spring. Also, the tolerable bending resistance of the connection has a greater capacity than the original steel connection (unreinforced).
Delay in local buckling
In composite sections, the steel column (compressed, non-compressed) becomes harder due to contact with hardened concrete, and its bending is delayed or does not occur. Therefore, until the contact between concrete and steel is reduced, such as cracking of concrete or separation of concrete and steel, the buckling will be delayed. Of course, in CFT columns, with the cracking of concrete due to preventing excessive expansion of concrete by the steel wall, the contact between concrete and steel will still be established. Therefore, the concrete core transfers lateral buckling modes to the outside, hence thinner steel sections are used to ensure that the yield strength is reached in the wall before buckling occurs.
High containment in concrete
Steel sections increase the confinement in the concrete core and then increase the strength and formability of the concrete. Due to the shape of the cross-section and the resulting annular stress or girdling stress, circular sections of CFT (CCFT) columns create more confinement than rectangular sections of CFT (RCFT) and SRC sections.
Saving construction costs
In CFT, the steel tube plays the role of a permanent mold for concrete, and this reduces human and material costs. The speed of construction with the CFT method is much higher, especially in medium to high-rise buildings. The cost of the members themselves is much less compared to the Fula structure, almost the cost of CFT is equal to the cost of reinforced concrete members. Also, compared to the steel bending frame, in the unbraced CFT frame, the amount of steel saving increases with the increase of floors. A relatively simple beam-to-column connection detail can be used. This issue reduces costs and eases design.
Using high-strength concrete, CFTs are stronger per square foot than conventional reinforced concrete columns. Where high resistance is desired, a smaller size of the column can be designed and the useful space of the building can be increased. A smaller and lighter skeleton is placed on the foundation. which will again reduce costs.
fireproof
In sections buried in concrete, concrete acts as a protection of steel section against fire. join Us @sazehcal
This post is written by radinbg