What is spiral reinforcement?

The reinforcement which is used in the spiral column is also known as helical reinforcement or spiral reinforcement. The Spiral reinforcement helps to support in the transverse direction. In the case of spiral column, the lateral expansion of the concrete is restrained by the spiral.

What is the role of reinforcement in RCC?

The purpose of providing reinforcement in R.C.C. is: To take up all the tensile stresses developed in the structure. To increase the strength of concrete sections. To prevent the propagation of cracks developed due to temperature and shrinkage stresses.

Why does a spiral improve the behavior of a column?

“Concrete columns reinforced with spiral reinforcement can withstand more loads than the tied columns . This phenomenon happens because when load eccentricities are small, spirally reinforced columns show greater toughness, greater ductility than the columns with ties.

What is the purpose of reinforcement in column?

The main role of transverse reinforcement in reinforced concrete columns is not to transfer the shear stress as it is mainly in the beams, but it is prevention buckling of longitudinal bars and transfer of tensile stresses, that arise in the orthogonal direction to the direction of compressive force action in the …

What is spiral column?

Spiral columns are cylindrical with a continuous helical bar wrapped around the column. This spiral provides support in the transverse direction. Tied columns have closed lateral ties spaced approximately uniformly across the column.

What is the formula for a spiral?

In modern notation the equation of the spiral is r = aeθ cot b, in which r is the radius of each turn of the spiral, a and b are constants that depend on the particular spiral, θ is the angle of rotation as the curve spirals, and e is the base of the natural logarithm.

What do you mean by reinforcement in RCC member?

Reinforced concrete (RC), also called reinforced cement concrete (RCC), is a composite material in which concrete’s relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility.

What is helical reinforcement?

Small-diameter reinforcement wrapped around the main or longitudinal reinforcement of columns, restraining the lateral expansion of the concrete under compression, and thus strengthening the column.

What is the function of transverse & longitudinal reinforcement in a column?

Transverse Reinforcement: To confine the concrete. To hold the longitudinal reinforcement in position. To prevent or delay sudden collapse and impart necessary ductility to the members.