Since water molecules are more attracted to other water molecules as opposed to air particles, water surfaces behave like expandable films.
Water surfaces behave in an unusual way because of cohesion. Water also exhibits a property of surface tension:. For example, a drop of water can stick to a glass surface as the result of adhesion. Adhesion Force: This force is responsible for the attraction between water and solid surfaces. Cohesion causes water molecules to stick to one another and form water droplets. Cohesion Force: Because of cohesion forces, water molecules are attracted to one another. Secondly, the amount of water in the soil depends upon how much water a soil may hold.īefore we discuss the capacity of soils to hold water, we must understand the concept of capillarity. First, soil water is intimately related to the climate, or the long term precipitation patterns, of an area. The amount of water in the soil is dependent upon two factors: Soil water, sometimes referred to as the soil solution, contains dissolved organic and inorganic substances and transports dissolved nutrients, such as nitrogen, phosphorus, potassium, and calcium, to the plant roots for absorption. Soil water is the medium from which all plant nutrients are assimilated by plants. Since soils vary in their degree of weathering, it is expected that soils have been affected by different amounts of water. Areas with high rainfall typically have highly weathered soils. Water is a necessary for the weathering of soil. The presence of water is essential for the all life on Earth, including the lives of plants and organisms in the soil. Soil water is important for three special reasons: 
Therefore, it is important to maintain proper levels of soil moisture. In addition to sustaining all life on Earth, soil water provides a pool of dissolved nutrients that are readily available for plant uptake. Soil water is particularly important in nutrient management. In nutrient management, a proper balance between soil water and soil air is critical since both water and air are required by most processes that release nutrients into the soil. It is named SULFATE ATTACK as follows: When the bricks containing in between the cement layer remain constantly in touch with water, the sulfates react with the tricalcium aluminate (C3A) in the cement to form tricalcium sulfoaluminate hydrate.Home > Soil Basics > Soil Composition > Soil Water There is still another way where by sodium sulfate will cause damage. These temperature and humidity conditions variations may cause fatigue phenomenon in the bricks and may, bring failure of the structure. It gets dehydrated if the vapor pressure of the hydrated salt is higher than atmosphere pressure whereby sodium sulphate can again absorb moisture in liquid or gaseous state and becomes Na2SO4
10H2O does not dehydrate (reverse process) when the relative humidity is near 100%. 7H2O) if temperature below 24.4✬ and then again be transformed into Na2SO4. Further, the anhydrous sulphate may also crystallize into unstable phase (Na2SO4 Between –1.42✬ and 32.4✬, it crystallizes decahydrate as monoclinic prisms at more than 32.4✬, it crystallizes in an anhydrous phase. For example, the crystallization of sodium sulphate from water solution in different shape is influenced by the change of temperature and quantity of water. Excess lime gets hydrated, swells and may decrease the mechanical strength of the bricks.The earth surface where the brick structure is constructed and water (rain or otherwise) generally contain two most common chemicals: the SO4-2 and Cl- (generally of Na+). Problems such as rising damp, moisture penetration and efflorescence on external walls, stains, fungi or algae growth, concrete corrosion, and loss of thermal insulation are due to water penetration.
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