Page 65 - AWSAR 2.0

Varun, always full of questions, asked, ‘Amma, what is our house made of ?’ I became excited to answer him as my civil engineering mode got activated and pointed out different
Dr Sripriya Rengaraju || 41
Me: Good question, dear. A lot of alternative materials are being tried out, but there are a lot of challenges in ascertaining whether they will work as expected. Even
structural elements with concrete and bricks. Then, his mind got tuned with mine, and he started asking questions like a viva-voce ‘Amma, what is concrete?’ I explained to him, Concrete is a mixture of cement, sand, gravel and water. Cement is the binding material, which, on the addition of water, reacts to form products that
bind sand and gravel. This
composite gets hardened,
giving us the required strength
and durability. ‘Amma, is this
cement?’ he asked, pointing to
the boiled rice as he used it to
stick his painting. I told him that
cement came from the industry
by burning some raw materials,
mostly natural resources in a
kiln. These natural resources
are fast depleting. Also, cement
production requires a lot of energy and pollutes the atmosphere. By this time, Varun got tired and slept. Seeing this, my husband started laughing. ‘Why are you trying to teach everything you do in your PhD to your son? You can teach me also,’ he said with a wink. Then, a serious conversation started.
Husband: If cement production is causing environmental pollution, then why are we not using some other material instead of cement?
before this, the lack of sustainability, in terms of supply and cost, is a point of concern.
Husband: There is an easy way out. In concrete, nowadays, people are putting everything right from the wastewater sludge to plastic. Think of some material that is naturally available and in abundance.
Me: Yes. Now you are getting into my research topic. 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.
Husband: Hey, we have been using this lime and clay for so long in our country.
What’s new?
Me: This cement uses low-grade limestone
and low-grade clay, the clay that is dumped due to its low kaolinite content and available in plenty in India. We don’t know how to get rid of it. As a bonus, these materials, when used in cement, help to attain early strength and also excellent resistance to the permeation of deleterious agents.
Husband: So, what is your research
A lot of new materials are coming into the market and have increased the pace
of construction. They hold promising potential for accomplishing housing for all. So, we all will get proper shelter very soon.