Page 66 - AWSAR 2.0

42 || AWSAR Awarded Popular Science Stories - 2019
about?
Me: We know that the concrete made
with this new cement has good ‘desirable’ properties. What we want to know is how it will behave when it is used for normal buildings, say a house? How is its corrosion performance?
Husband: You are going to research about corrosion? Do you have any idea how long it will take to corrode? It will take years!! And I remain a student’s spouse such long!!!?? Are you kidding me?
Me: No. Don’t get into that mode. Listen. There are different short-term and long-term test methods in the literature. I am going to try out some of them to assess the corrosion performance. I have already tried out one of the short-term test methods by applying a potential. I found that because of greater resistance developed in this new concrete due to the denser matrix, the embedded steel has different surface properties and does not experience as much corrosion
as that of conventional
concrete. This is a new finding,
and I am going to write a paper
for publication.
Husband: Thank God. Then, that means your Ph.D. is going to be over soon. I am happy now. When you told you are going to research in corrosion, I felt a little hesitant.
Me: Haha! This is not the
end of the story. I have done
testing of the new cement with
a long-term test method by subjecting it to the natural wet-dry cycle also. Since this cement is highly resistive, the measured response and data interpretation based on the conventional methods are misleading.
Husband: Then, how are you going to overcome this?
Me: I am developing a new test method for testing such highly resistive cement when
it is subjected to chlorides in its environment. Different types of cement need a different amount of chlorides for the initiation of corrosion in the embedded steel. This amount of chloride is called the chloride threshold of that particular steel–cement combination. It is generally believed that if the chloride threshold is smaller, then the combination does not ensure the longer service life of structures. But, all the alternative materials have a lower chloride threshold than the conventional cement.
Husband: Are you saying these alternative binders are bad?
Me: No. What I am saying is that these alternative binders have higher resistance towards the penetration of chlorides. They offer excellent resistance against corrosion and provide longer service life even though they have lower chloride threshold.
that?Husband: How are you going to prove
Me: That is the main reason why I did not stop at that point and continued to give an overall picture. I developed nomograms/design charts to make the judgement of such new materials for their potential in reducing the environmental impact and ensuring longevity. These charts enable us to predict the service life for the chosen materials at the site. For example, if we have three choices, we can compare the
cost and service life and make wise choices in terms of material selection. This nomogram is going to come in the design standards soon to check the durability. My professor is talking about its application and the ease of use with various standard bodies.
Husband: Oh, great. Now, I am hungry. If you start talking about your research, you will forget what’s going on around you. Shall we have dinner, please?’
There are already greater minds that thought about it and developed a new type of cement called limestone calcined clay cement (LC3). They made about 50% replacement of the typical cement, which we use with clay and limestone.