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When atmospheric carbon dioxide (CO 2), or carbonate ions (HCO − 3, CO 2− 3 dissolved in water) diffuse into concrete from its external surface, they react with calcium hydroxide (portlandite, Ca(OH) 2) and the pH of the concrete pore water progressively decreases from 13.5 – 12.5 to 8.5 (pH of water in equilibrium with calcite).
Excessive moisture vapor emissions in concrete slabs can mean significant, expensive damage to a flooring installation. Hundreds of millions of dollars are spent annually just in the United States to correct moisture-related problems in flooring. [1] These problems include failure of the flooring adhesive; damage to the floor covering itself ...
Sulfate attack typically happens to ground floor slabs in contact with soils containing a source of sulfates. [2] Sulfates dissolved by ground moisture migrate into the concrete of the slab where they react with different mineral phases of the hardened cement paste. The attack arises from soils containing SO 2−
The effect of seasonal variations in evaporation rate on the height of moisture rise have been comprehensively described. [ 50 ] A review of data and publications commissioned by the Property Care Association and carried out by the University of Portsmouth [ 27 ] concluded that "Rising damp is an age-old and ubiquitous problem."
The water will slowly seep into the ground and make its way into soil. It’s recommended to use the soaker hose method at least three times a week for around 15 to 20 minutes each time.
Damp proofing in construction is a type of moisture control applied to building walls and floors to prevent moisture from passing into the interior spaces. Dampness problems are among the most frequent problems encountered in residences. DPC visible between concrete foundation and brickwork.
The speed of carbonation depends primarily on the porosity of the concrete and its moisture content. Carbonation in concrete pores happens only at a relative humidity (RH) of 40-90%—when RH is higher than 90%, carbon dioxide cannot enter the concrete pores, and when RH is lower than 40%, CO 2 cannot be dissolved in water. [28]
The alkali–silica reaction (ASR), also commonly known as concrete cancer, [3] is a deleterious internal swelling reaction that occurs over time in concrete between the highly alkaline cement paste and the reactive amorphous (i.e., non-crystalline) silica found in many common aggregates, given sufficient moisture.