Roll No: 14MST1019

Name: Ramya A

CORROSION AND PREVENTION METHOLOGIES The importance form of corrosion is the rusting of steel. The major bridges and buildings which are subjected to corrosion results in the life cycle cost are very higher in the well developed countries such as USA, Canada. The recent studies was made in the year of 2012, we came to know that for repair and rehabilitation work of direct cost nearly equal to Rs.2lakhs crores per year.

The mechanism of corrosion has four types of processing. They are collection of iron ore raw materials, blast furnace, molten state and rolling to desired shape.

During the process of molten state adding lot of heat energy and mechanical energy to the material.

If it is exposed to weathering conditions results in the rust formation of steel and again it come back to original position as an iron ore. To measure the corrosion on concrete done by simply spraying phenolphthalein. The region is colour less denotes the state of carbonate affected and pink colour indicates that not yet affected from corrosion. Two types of corrosion take place on the concrete. One is carbonation induced this permit to increase the level of kind of uniform corrosion and chloride induced is nothing but formation of pit shaped corrosion.

Chloride content can attack the steel rebar and once the passive layer is broke down. Its difficult to stop reaction as long the sufficient oxygen. Main objective not to reach the chloride content into steel because of that only providing optimum cover. Steel get expands 6 times then pressure exerted to concrete results in the crack. According field engineer concern expansion of steel is good. It shows the warning of steel has corroded. Corrosion shall be checked in the probabilistic manner. Core-crete enhances the strength as well stirrups. Cover-crete enhances durability of concrete. Curing is another important factor for cover-crete to achieve good strength.

Its tedious to measure chlorides at surface of concrete. For minimum thickness it will take few decades.

Use any by product waste such as silica fume (below 5%), slag and fly ash to increase the strength. Slag is better than fly ash to control the chloride content. The workflow criteria from prescription to performance basis.