Essay On Sabkha

1. Sabkha

Definition

Sabkha is an Arabic expression for a flat and very saline area of sand or silt lying just above the water table usually between a desert and an ocean or salt lake. It is characterized by a crusty surface containing recent coastal sediments with a high salt content (including salt, gypsum, halite, anhydrite and calcium carbonate) as well as windblown sediments and often-tidal deposits. Sabkha’s come into general use in sedimentology following classic research in the United Arab Emirates of the Arabian Gulf in the 1960s and later. Sabkha soils form primarily through the evaporation of seawater that seeps upward from a shallow water table and through the drying of windblown sea spray. [1]

Sabkha soils are known to have a very low bearing capacities and low SPT values. They are widely distributed in the Arabian Peninsula. The existence of sabkha is

The high concentrations of chloride and sulfate salts in sabkha brine are known to be highly corrosive to both concrete and steel reinforcement. Moreover, the conjoint prevalence of these salts poses several unresolved questions regarding their concomitant, and sometimes cumulative, interaction with reinforced concrete foundations. The problem is significantly intensified by the co-existence of intermittent, but regularly occurring, moisture with this high salt content that is liable to produce the worst conditions and the most severe deterioration. Further, the crystallization of these salts in the concrete pores often leads to its slow disintegration due to pressures caused by the crystallization power of salts. This form of crystallization-induced disintegration in the concrete foundation usually occurs above the water table, where crystallization is enhanced by evaporation. The various forms of brine attack present severe conditions for ordinary "Portland cement" and warrants strict precautionary