a large number of bridges and buildings that are currently used, are made of slabs with opening. some of these buildings and bridges have been severely damaged because of natural disasters such as earthquake, storm and other effects such as materials fatigue and alkaline and corrosive agents. therefore, retrofitting and strengthening of these structures is essential and affordable. in this rese...

The voided slab system has been known as an effective technique to replace a heavy reinforced concrete without the decrease in flexural strength. However, according previous studies, capacities such strength, stiffness and ductility of slabs were practically lower than that solid depending on void shapes details. Therefore, this study, analytical experimental study conducted derive optimal shap...

The deteriorating national infrastructures demand improved non-destructive evaluation (NDE) methods for detection of defects which reduce the integrity of the structures. Vibration resonance tests offer an efficient NDE method to identify and characterize shallow (near surface) delamination defects in reinforced concrete slabs In this study, we compare the capability to visualize near surface d...