Sustainable Solutions For RCC Foundation Durability: Case Studies in Aggressive Subsoil and Groundwater Conditions-Paper

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The paper presents two case studies on protecting reinforced-concrete (RCC) foundations from highly aggressive soil and groundwater. Chlorides can disrupt the protective layer around reinforcement, while sulfates and acidic conditions can damage concrete, causing cracking, spalling, and corrosion. The authors emphasize a site-specific, layered durability strategy combining low-permeability concrete with additional barriers or corrosion protection.<br /><br />At a refinery expansion on former fertilizer and gypsum-disposal land, groundwater had a pH of about 3–4, with high chloride and sulfate concentrations. Because the acidity made a steel pile liner unsuitable, the design used M40 concrete with composite cement, a water-cement ratio no greater than 0.40, supplementary cementitious materials, corrosion-inhibiting admixtures, corrosion-resistant reinforcement, and increased concrete cover. Piles received sacrificial-anode cathodic protection; pile caps and shallow foundations were protected with polyethylene membranes and epoxy coating.<br /><br />At a former salt-mining site in western Rajasthan, groundwater chloride concentrations reached 108,000 mg/L. The design used M35 self-compacting concrete with Portland slag cement, Alccofine, admixtures, a water-cement ratio of 0.38, and increased cover. Piles were protected with sacrificial steel liners, while foundations received a multilayer waterproofing system incorporating HDPE and SBS membranes, with protective dimple board.<br /><br />Concrete testing indicated very low chloride penetrability, water penetration depths of 4–8 mm, and acid-soluble chloride levels within the specified limit. The case studies show that combining dense, low-permeability concrete with protective systems—and adapting those systems to local chemistry and construction constraints—can improve foundation durability in extreme environments.

Keywords

reinforced-concrete foundations

chloride attack

sulfate attack

acidic groundwater

durability strategy

low-permeability concrete

cathodic protection

waterproofing membranes

corrosion-resistant reinforcement

case studies