International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019
p-ISSN: 2395-0072
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Study of Effect of Chemicals (Acid) Attack on Strength and Durability of Hardened Concrete Shripad Umale1, Prof G.V Joshi2 1PG
Student, G H Raisoni College of Engineering and Management, Wagholi, Pune, India. Professor, Department of Civil Engineering, G H Raisoni College of Engineering and Management, Wagholi, Pune, India. ----------------------------------------------------------------------***--------------------------------------------------------------------2Asst.
Abstract - In recent century, the use of concrete has
out of Portland cement, supplementary cementitious material, water, aggregates, and depending on its application and the requirements of a specific project, different types of chemical and mineral additives may be used in its production.
increased tremendously in all types of construction varying from industrial, residential, water storage, infrastructure and so on.. This material is generally highly durable and can be made to possess superior mechanical properties, such as high compressive and flexural strengths. When it comes to resistance to different types of chemicals, the durability of concrete is quite influenced by its manufacturing process (curing methods, finishing, etc.) and the materials that are used. It is well known that concrete deteriorates when exposed to chemical attack under acidic environments. Concrete structures may be subjected to acidic environments under variety of conditions such as acid spills, acid rains, drainage sewers, chemical factories, hot springs, industrial effluents, etc. In above cases, the acid that affects concrete may be different. Also, the duration of attack may range from few seconds to years.
When it comes to resistance to different types of chemicals, the durability of concrete is quite influenced by its manufacturing process (curing methods, finishing, etc.) and the materials that are used. It is well known that concrete deteriorates when exposed to chemical attack under acidic environments (Fig.1). Concrete structures may be subjected to acidic environments under variety of conditions such as acid spills, acid rains, drainage sewers, chemical factories, hot springs, industrial effluents, etc. In above cases, the acid that affects concrete may be different. Also, the duration of attack may range from few seconds to years.
In the present study, an attempt is made to study the effect on acid exposure on strength of concrete through experimentation. Concrete cubes of single mix will be prepared and exposed to different concentration of Hydrochloric, Sulfuric and Nitric acid for 30 and 60 days. A total of 87 cubes of size 150mm x 150mm x 150mm are cast with M20 grade of concrete as per mix design mentioned above. Following which the cubes are immersed (cured) in water for 28 days. Next, the cubes are immersed in and sprayed with 5% and 10% concentrated acids like Hydrochloric acid, Sulphuric acid and Nitric acid for 30 days and 60 days. The cured cubes are then tested under compressive testing machine to determine their compressive strength. Fig -1: Deterioration of Concrete Structure
Key Words: Hydrochloric acid, Nitric acid, Sulphuric acid, Compressive strength.
The spectrum of aggressive acidic media is wide. Acidic attack usually originates from industrial processes, but it can even be due to urban activity. Even natural exposure conditions may cause acid attacks. Free acids in natural waters are rare. Exceptions are carbonic waters and sulfurous and sulfuric acids in peat waters. Soils may contain huminous acids. Several organic and inorganic acids may occur in shallow regions of sea-water as a consequence of bacteriological activity. Significant quantities of free acids in plants and factories may be found. In these cases, the concentration of acid, which comes in contact with concrete structures, may reach to high values.
1. INTRODUCTION In recent century, the use of concrete has increased tremendously in all types of construction varying from industrial, residential, water storage, and infrastructure and so on. It is interesting to note that the word ‘concrete’ comes from the Latin word ‘concretus’ which means compact or condensed. This material is generally highly durable and can be made to possess superior mechanical properties, such as high compressive and flexural strengths. It is typically made
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