The behavior of high-strength reinforced Concrete columns under axial and cyclic lateral Loads

الملخص EN

A two-phase experimental program is being carried out to study the effect of including steel fibers on the behavior of high-strength reinforced concrete (HSC) columns subjected to constant axial load combined with cyclic lateral loading in order to simulate the case of seismic action.

This paper presents the results of the first phase in the program, which consists of seven square HSC columns.

The main parameters of the first phase were : longitudinal reinforcement ratio, percentage of steel fiber and stirrups ratio.

Each specimen represents a column extending on both sides from the beam-column connection to the location of the point of inflection.

Particular attention is paid to the effect of each variable on the strength enhancement, stiffness degradation, energy dissipation capacity and ductility of the tested columns.

Valuable conclusions were obtained from the research results.

A percentage of 2 % longitudinal steel is chosen to be suitable for HSC columns in seismic regions.

Using 1 % steel fiber is recommended in HSC columns in seismic zones.

The Egyptian concrete code of practice limits for the columns stirrups is suitable in seismic zones.

The second phase of the experimental program is carried out to study the effect of axial load level, compressive strength, and aspect ratio on the behavior of the high strength concrete columns under axial and cyclic lateral loads.