WebOct 15, 2006 · Understanding the mechanisms leading to chemical attack on concrete is crucial in order to prevent damage of concrete structures. To date, most studies on sulfate attack and thaumasite formation are based on empirical approaches, as the identification of associated reaction mechanisms and paths is known to be highly complex. WebInternal and external sulfate attacks of concrete. The formation of ettringite in the hardened cement paste is an internal expansive chemical reaction that can lead to severe degradation of concrete. ... this precaution is insufficient to completely eliminate the risk of formation of thaumasite (TSA) because this latter can still develop ...
AFt phases - Wikipedia
WebThere are two different formation mechanisms of TSA. One is the direct formation, and the thaumasite is formed through the reaction among C-S-H, calcite, unbound sulfate ions, and moisture [ 12 – 14 ]. For the indirect formation, the thaumasite is formed through the reaction among ettringite which forms first, C-S-H, carbonate, and water [ 15 ]. WebAlthough, thaumasite can develop alone at low temperature in the absence of ettringite (AFt), thus even in sulfate-resisting cement (SR0 cement without C 3 A), the presence of ettringite (AFt) acts as a scaffold (template, chaperone) for thaumasite crystallization and therefore favors its formation by hetero-epitaxy. mariner poem about caesar\u0027s mighty realm
Mechanism of Thaumasite Formation in Concrete
WebAbstract: Significant efforts have been made in revealing the mechanism of thaumasite formation in concrete, which continues to be fraught with ambiguities and dissension. … WebEste proceso, conocido como formación retardada de etringita (DEF: delayed ettringite formation), presenta baja incidencia de casos reales en obra [16]. Para evitar el ataque interno por sulfatos, la Instrucción EHE-08 y la Instrucción RC-16 fijan los siguientes límites a los componentes del hormigón (Tabla 2). WebSpecialties: FIELD OF INTERESTS - durability of concrete in general - chemical deterioration mechanisms of concrete/mortar/paste - sulfate attack on concrete (internal-DEF, external) Igor Cigrovski is currently working on a research dealing whit the Concrete Corrosion. More precisely dealing whit the Sulfate Attack on Concrete.He leaved his PhD position at the … mariner point park boat launch