Efflorescence has been one of the biggest headaches for the concrete product producers. This is exceptionally crucial for the architecture or aesthetic concrete item producers. Efflorescence might be easily explained as white deposits on the concrete surface. Nonetheless, there is a exceptionally broad science behind this phenomenon. Based on the literature, this condition occurs mainly in poorly constructed concrete. Poorly constructed concrete indicates the one with insufficient curing, and also the 1 with considerable level of pores or cracks. Efflorescence is actually dried Calcium Carbonate (CaCO3), which formed from the reaction between Calcium Hydroxide (Ca(OH)2) from the hardened concrete and Carbon Dioxide (CO2) inside the air. Ca(OH)2 is really a by-product of hydration method. The presence of Ca(OH)2 is proportionate to the presence of C3A content in the cement. Therefore to decrease the Ca(OH)2 content in concrete, the C3A content must be reduced in the cement. One of many approaches to decrease the C3A content in cement is by replacing portion of the cement with pozzolans (specially the slag). The pozzolanic material will react with Ca(OH)two in the mix, thereby lowering or often eliminating the chances of Ca(OH)two leaching out of concrete. Secondly, by adding pozzolanic material, the C3A content is reduced, and consequently it creates considerably lesser Ca(OH)2. This is how the pozzolanic material helps to decrease efflorescence. There may be also another way of reducing (eliminating) efflorescence on concrete surface. If the calcium hydroxide might be converted into hydration item, then this can help to reduce the efflorescence issue. The most useful hydration item in concrete may be the calcium silicatecalcium silicate hydrate (C-S-H). Therefore, a silicate must be introduced inthe concrete in order to get the Ca(OH)two hydrated. The hydration between Ca(OH)2 and silicates will produce C-S-H. Theoretically it sounds possible, but how and when to introduce the silicates is completely one more problem to deal with.
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