However, itsignificant differences can be easily recognized significant differences between specimens on the formation and development of cracks, as well as itstheir failure modes. The observations of the structural response of specimen S1 when subjected to the combination of seismic load and low axial load indicated that the column collapse was mainly due to high shear stresses and the increasing of the seismic load, accompanied by a clear change from the flexural to the shear performance of the column. Firstly, when input acceleration was low (EQ2); it was, only observed horizontal cracks were observed on the external face of the weak flange due to the overturning moment, meanwhile. Meanwhile, there was no observed concrete cracking on the strong flange (refer to Figure 2a). Higher input acceleration accompanied the appearance of inclined cracks on the strong flange and these cracks were developed dramatically to spread into the internal face of the column (as shown in Figure 1bc1 b, c, d), and eventually resulted in the collapse of the column. In contrast, for specimen S2, with the moderate axial load, horizontal cracks due to the flexural action accounted for the majority of observed cracks during the test and there were only two inclined cracks observed at the failure state. It was strongly believed that there was no change in the working state of the column as the specimen S1 and it was collapsed fully due to high flexural stresses.