Which type of pipe requires special external protection in high-chloride soils?

The type of pipe that requires special external protection in high-chloride soils is reinforced concrete. Reinforced concrete piping is often used in water distribution systems due to its strength and durability. However, when it comes into contact with high-chloride environments, such as coastal areas or certain industrial sites, there's a risk of corrosion or deterioration of the concrete material, especially at the areas where it is reinforced with steel.

In these environments, chloride ions can penetrate the concrete and lead to corrosion of the embedded steel reinforcement bars over time. To mitigate this risk, reinforced concrete pipes typically need additional protective measures, such as coatings or special linings, to enhance their resistance to corrosive agents present in high-chloride soils.

Other types of pipe materials, such as ductile iron, steel, and high-density polyethylene, also have their considerations regarding corrosion and environmental factors, but reinforced concrete is particularly impacted by high-chloride conditions and therefore requires significant external protection to ensure longevity and reliability in such soils.