The National Commercial Bank (NCB) located in Jeddah, Saudi Arabia, is a leading financial institution and the biggest in the region. As of 2014, the Bank operates 342 branches throughout the Kingdom, dedicated exclusively to Islamic banking services for over 4 million clients.  The NCB headquarters which is located in a distinctive high-rise building is part of a plaza of 1.2 hectares located on the edge of the sea.

After conducting a visual inspection of the NCB building parking structures, Kabbani Construction Group (KCG) noted the presence of cracks and detached concrete pieces in several elements of the parking that was built in 1979.

SIMCO was hired by KCG to perform a condition assessment and service-life evaluation of the NCB’s parking structure. The objective of the investigation was to provide insight into the cause(s) of cracking, from a materials perspective, to evaluate the condition of the concrete and to evaluate the residual service life, based on the degradation mechanisms at work on the structure.

A laboratory testing program was performed on concrete cores extracted from the different structure elements in order to provide information on the mechanical properties and characteristics of the concrete as well as the possible degradation mechanisms at work on the different concrete elements. Data provided by the laboratory investigation were then used to perform service-life calculations with SIMCO’s STADIUM^® numerical modeling tool in order to evaluate time to corrosion initiation.

Analyses showed that, in the case of the NCB parking, corrosion initiation is mainly driven by carbonation. The combination of poor-quality concrete and sheltered/indoor exposure creates an environment resulting in high carbonation rates. The carbonation rates were calculated and corresponded with data found in the literature for comparable concretes and exposure conditions.

A complete condition assessment report was provided including results from analyses conducted to determine the causes of the deterioration observed. A cost-optimal repair and maintenance plan was recommended.

Client Objectives

• Determine the current condition of the different parking structure elements
• Identify the cause(s) of the deterioration observed
• Evaluate the residual service life of the different concrete elements
• Establish the most cost-effective repair and maintain options

SIMCO’s Solution

• Perform materials characterization and analyses to determine deterioration levels
• Perform numerical calculations using STADIUM® to evaluate time to corrosion initiation based on two distinct degradation mechanisms
• Provide recommendations for the most efficient repair and maintenance options

Results

• A better understanding of the current condition of the structure
• Identification of deterioration mechanisms at work on the different concrete elements
• An optimal repair and maintenance plan to ensure the structure reaches its designed service life