Experimental Analysis on performance of Engineered Cementitious Composite with Reactive Nano, Micro MgO, Micro Tio 2 at Normal and H 2 So 4 acid conditions

Abstract

Abstract Engineered Cementitious Composite (ECC) is one of the high-performance-based structural components. The materials used in the preparation of this composite are responsible for its characteristics. To improve structural safety against acid rains, the impact of one of the significant acids (H2So4) on mechanical, durability, and microstructural characteristics of Nano MgO based ECC with the different fine aggregates namely, Silica sand, Indian Zone II River sand and Manufactured sand is analyzed. For this, three mixes (Mix-A with silica sand, Mix-B with river sand, Mix-C with 50% River sand+ 50% Manufactured sand) were considered and cast specimens. In the composition, a suitable content of Micro MgO and Micro Tio2 are available. These specimens are kept for 28days under water curing before placing in an acidic solution and normal (atmospheric at 25 to 400C) conditions. The performance of acid (5% concentration) exposed specimens is compared with the normal atmospheric conditions after 28days. Three layers are formed on the surface of each specimen at acid exposure and 2layers are formed under normal conditions. A small layer of Caco3 + Tio2 formed on top of the specimens, this was responsible for photocatalytic action to reduce Co2 into fuels. Below this layer, the brucite layer formed on the specimens that reduced further exposure to acid. Apart from this, the Gypsum layer formed in the acid-exposed specimens. All these layers are formed by the chemical reaction of Nano MgO, Micro MgO and Tio2 with other materials. These reactions were also responsible for the almost same strength and densification under both conditions. But Mix-C showed better performance than other mixes due to the presence of high content portlandite and micro MgO that are responsible for an increase in the thickness of layers.