Yasser E. Ibrahim

Seismic fragility curves for mid-rise reinforced concrete frames in Kingdom of Saudi Arabia

This article is concerned with the development of seismic fragility curves for typical mid-rise plane reinforced concrete moment-resisting frames in Kingdom of Saudi Arabia (KSA), which is considered as low-seismicity area. Two structural models; four- and eight-storey moment-resisting frames were considered. Three cities with different seismic intensities, Abha, Jazan and Al-Sharaf, were selected to cover various values of mapped spectral accelerations in KSA. The 0.2-s spectral accelerations range from 0.21 to 0.66 g, while the 1.0-s spectral accelerations range from 0.061 to 0.23 g. The structural models were designed under dead, live and seismic loads of these cities according to the Saudi Building Code. Incremental dynamic analysis was performed under 12 ground motions using SeismoStruct. Five performance levels, namely, operational, immediate occupancy, damage control, life safety and collapse prevention were considered and monitored in the analysis. Fragility curves were developed for the structural models of the three cities considering the five selected performance levels.

Seismic Performance Evaluation of Residential Structures in Egypt

In this research, analytical fragility curves for three existing structures are presented. Structures are 2-story, 6-story and 10-story residential reinforced concrete structures designed under dead ,live and seismic loads of zone 3 according to Egyptian code (2008). The design acceleration is 0.15g. The fragility curves are developed based on nonlinear incremental dynamic analysis of three dimensional structural models using SeismoStruct under twelve historic ground motions. Four performance levels are considered; fully operational, operational, life safe and near collapse.

Destructive and Nondestructive Testing on Silica Fume Concrete

Factors such as poor design, bad workmanship and a harsh environment can combine to cause deterioration within a concrete structure leading to visually unacceptable surface cracking or spalling of concrete cover [. In aggressive environments, corrosion of steel reinforcing bars is responsible for major deteriorations in concrete structures. Reduction in bar diameter leads to a lower resistance, which can result in brittle failure of the bar. Initiation and progression of reinforcing steel corrosion can lead to progressive weakening of the structure due to damage accumulation over a period of time, or in sudden catastrophic failures, such as the Berlin Congress Hall, a parking garage in Minnesota [. Antonaci et al. [ conducted an experimental study on different concrete cylinders damaged in compression followed by means of linear and nonlinear ultrasonic methods. Arndt et al. [ tested a concrete slab representing typical bridge decks in order to evaluate the ability of NDT methods to detect different phases of corrosion progression in concrete. Reinforced concrete beam-shaped samples were tested by Aveldano and Ortega [ in order to characterize concrete cracking due to reinforcing corrosion under different environments. Shah and Ribakov [ performed nonlinear ultrasonic testing of cubic concrete specimens with different frequency transducers. Al-Amoudi et al. [ investgated the relatioship between compressive strength of ordinary concrete and blended cement concrete with durability propeties of concrete samples and conculded that the addition of blended cement will improve the performance of concrete in ressiting corrosion of reinforcement. The main objective of this study is to investigate the effectiveness of using nondestructive testing to assess the performance of different types of concrete such as OPC and SFC. Also, to correlate different types of nondestructive testing and to investigate the possibility of capturing the occurrence of corrosion in reinforcing bars in concrete.