A THESIS SUBMITTED TO ARBA MINCH UNIVERSITY, INSTITUTE OF TECHNOLOGY, SCHOOL OF GRADUATE STUDIES, FACULTY OF CIVIL ENGINEERING IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTERS SCIENCE IN STRUCTURAL ENGINEERING.

Abstract

It is uncommon to see longitudinal openings in RC columns to conceal pipes. This thesis, a three dimensional Mesoscale Numerical study, investigates on size (height) effect of RC columns with longitudinally positioned concealed pipes at the center of the cross-section subjected to axial compression loading. RC columns full-scale experimental results reported from the literature are used for validation using ANSYS Mechanical APDL nonlinear finite element analysis. Further parametric studies are performed on RC columns with holes positioned longitudinally at the center of their cross-sections by considering different parameters such as the shape of the hole, the size of the hole, the shape of the column, and a height difference of the column. Finite Element analysis (FEA) results showed that changing the shape of a hole from circular to square has a significant effect on the load-bearing capacity of the RC column. Square RC column with a square hole significantly reduced the load-bearing capacity of the column by 47.92%, and rectangular RC column with square hole increased load bearing capacity by 11.83%. Increasing the size of the hole by 50% reduced the load-bearing capacity of the column by 35.54%, 11.25% for square and rectangular RC column respectively. The RC column with a hole having a height difference of 75% reduced the load-bearing capacity of the column by 64.4%, 71% for square and rectangular RC column respectively. Changing the shape of a hole from circular to square, increasing the height of the column by 75%, Von Mises stress reduced by 0.08%, 55.07% respectively. RC column at the height difference, changing the shape of hole from circular to square, the longitudinal strain decreased by 85.4%, 16.7% respectively. In a comparison of the shape of reinforced column with hole, the load-bearing capacity of rectangular reinforced column reduced by 41.2% than square reinforced column