Durability of Concrete Structures in Persian Gulf

Corrosion of Embedded Metals: Corrosion of reinforcing steel and other embedded metals is the leading  cause of deterioration in concrete. When steel corrodes, the resulting rust occupies a greater volume than the steel. This expansion creates tensile stresses in the concrete, which can eventually cause cracking, delamination, and spalling.

Carbonation: Carbonation occurs when carbon dioxide from the air penetrates the concrete and reacts with hydroxides, such as calcium hydroxide, to form carbonates. In the reaction with calcium hydroxide, calcium carbonate is formed:
This reaction reduces the pH of the pore solution to as low as 8.5, at which level the passive film on the steel is not stable.

Lightweight aggregate concrete can be produced using a variety of light-weight aggregates. Lightweight aggregates originate from either:
- Natural materials like volcanic pumice
- The thermal treatment of natural raw materials like clay, slate or - shale i.e. Leca
- Manufacture from industrial by-products such as fly ash, i.e. Lytag
- Processing of industrial by-products like FBA or slag

Lightweight aggregate concretes can however be used for structural applications, with strengths equivalent to normal weight concrete.
The benefits of using lightweight aggregate concrete include: 
- Reduction in dead loads making savings in foundations and reinforcement.
- Improved thermal properties.
- Improved fire resistance.
- Savings in transporting and handling precast units on site.
- Reduction in formwork and propping

Fiber reinforced concrete (FRC) is concrete containing fibrous material which increases its structural integrity. It contains short discrete fibers that are uniformly distributed and randomly oriented. Fibers include steel fibers, glass fibers, synthetic fibers and natural fibers. Within these different fibers that character of fiber reinforced concrete changes with varying concretes, fiber materials, geometries, distribution, orientation and densities.

• Accelerators speed up the hydration (hardening) of the concrete.
• Retarders slow the hydration of concrete, and are used in large or difficult pours where partial setting before the pour is complete is undesirable.
• Air entrainments add and distribute tiny air bubbles in the concrete, which will reduce damage during freeze-thaw cycles thereby increasing the concrete's durability.
• Plasticizers (water-reducing admixtures) increase the workability of plastic or "fresh" concrete, allowing it be placed more easily, with less consolidating effort.
• Superplasticizers (high-range water-reducing admixtures) are a class of plasticizers which have fewer deleterious effects when used to significantly increase workability
• Pigments can be used to change the color of concrete, for aesthetics.
• Corrosion inhibitors are used to minimize the corrosion of steel and steel bars in concrete.
• Bonding agents are used to create a bond between old and new concrete.
• Pumping aids improve pumpability, thicken the paste, and reduce dewatering – the tendency for the water to separate out of the paste.

• Fly ash: A by product of coal fired electric generating plants.
• Ground granulated blast furnace slag (GGBFS or GGBS): A by product of steel production.
• Silica fume: A by-product of the production of silicon and ferrosilicon alloys.
• Metakaolin: Metakaolin produces concrete with strength and durability similar to concrete made with silica fume

Glass Fiber Reinforced Concrete (GFRC) is a type of fiber reinforced concrete. Glass fiber concretes are mainly used in exterior building facade panels and as architectural precast concrete.