First Ever AAC Conference of India
This was when all the owners/producers, suppliers, vendors came under one roof for the very first time on a national level.
From Himalayas in the north to Kanyakumari in south, from the Bay of Bengal in the east to the western ghats in the west, most of the AAC owners were present in the conference. No one was from North, or south, east or from west, but everyone was from the AAC Industry of India.
Also, apart from India, there were people present from all over the world, particularly from the seven countries like Sweden, Egypt, Hongkong, Nepal, Netherlands, Germany, and Turkey.
With this heightened spirit of unity with a mix of professionalism and collaborative mindset, the conference began. I was a speaker and I had to give a speech on our AAC India Institute from stage. For me it was the very first time on stage infront of so many bigshots and highly professional people. No doubt I had been on stage beforehand as well, but not in front of such highly professional people. Also, being the youngest man in the room (Just 24) contributed to my nervousness.
As people were finishing their speeches and my turn to go on stage was approaching, my heart beats were steadily heaving. As my turn came and the anchor announced my name, I approached the stage with a clouded mind. Before me, my father had given his speech, which had obviously been as impactful as it always has.
So, he was climbing down and I was climbing up the stairs. When he passed me, I immediately turned and touched his feet and obtained an in-direct blessing. When I finally was on stage, I saw the crowd of professionals and time seemed to slow down. There was no small producer, or big producer of AAC. There was no vendor, or supplier in AAC. There was only the AAC Industry that I was witnessing shaping infront of me. What an incredible visual it was. Experiencing all this for the first time was a bit heavy for me. The air seemed to get thinner and my hands seemed to shake with fear and nervousness.
But that was the time I reminded myself, that whenever I am on stage, the stage is mine!! I don’t let my mind get enslaved by my own thoughts, in fact I become the dictator of my thoughts. Inhaling the courage from my previous stage experiences, I started my presentation. As my time on stage was journeying towards conclusion, I observed that all were paying deep attention to my every word. Maybe it was because of my so assertive style of speech. My presentation ended, and I came down from the stage. And people had genuinely enjoyed my time on of speech. The majority of feedbacks were – “Ojas, you have a great voice and passion for whatever you do which reflects in your words” and “Ojas your presentation was ‘non eye-blinkable’.”
Now obviously know that I have a long way to go. And such praising should not make me feel on the top of the world. But some positivity is always welcomed and is so obviously expected…!!!
Anyway, I will always try to contribute my sweat and blood for AAC industry, and not only of India, but of the world.
Penning these words, I give a full stop to this issue’s editorial.
Ojas Joshi,
Co-founder,
AAC India Institute.
02 Current Happenings
The CEO of MJ Consulting Company, Mukund Joshi, was invited to Nepal’s first ever AAC Conference as a “keynote speaker”. And this is what he wants to share with us.
Why Clay Bricks Need to Go Out: And AAC Needs to Come In
(His Keynote Speech in the First Nepal AAC Conference)
I am grateful to ABMA – the Nepal AAC brick manufacturers Association – for inviting me as a keynote Speaker for their very first Nepal AAC conference this month.
Like many parts of the world, Nepal is still dominated by the red clay brick Market. This picture pains me a lot.
I have devoted many many years of my life in promoting AAC not only in India, but in many parts of the world. And in every place that I visit, I still find the same prejudice against AAC. The situation is not different in Nepal.
Hence, I took up the challenge, and in my Keynote address, I compared AAC with red bricks on various parameters. I was fortunate that many prominent architects and structural consultants were present in this conference of Nepal.
I demystified many of the myths surrounding AAC in my speech and the audience loved it.
I am giving a brief summary of my speech below. Although many of these points are common knowledge now – but still, someone has to stand on the podium and is required to say it forcefully – to make the bitter pill swallow.
- The mining activities to remove the top soil for brick manufacturing is a disaster for our planet – resulting in loss of vegetation, surface water run-off and deforestation. BUT WHO CARES?
- The CO2 emitted by brick kilns is three times that of AAC manufacturing – causing massive environmental pollution. BUT WHO CARES?
- Clay bricks weigh more than twice as much as AAC blocks – tremendously increasing the dead load on our buildings, which is a problem. Because remember, they are just partition walls. This additional dead-load on the building increases the construction cost by a lot.
BUT WHO CARES?
- AAC Blocks (due to their lightweight nature) are far more earthquake resistant than clay bricks. Hence Turkey, after their massive earthquake in Feb 2023 resulting in deaths of 50,000 people, have shifted to AAC in a big way. Look what has happened to Thailand and Myanmar in this week. So many deaths and so much destruction. BUT WHO CARES?
- AAC is better than clay bricks in every other aspect – better Heat insulation, comfortable living for residents, faster speed of construction, lower construction cost, accurate in size, shape and quality parameters, and a great green material. BUT WHO CARES?
During my speech, I also shared a three point methodology to avoid any shrinkage cracks in the walls and demonstrated it with practical videos to the audience.
Thankfully, the red clay bricks are fully banned in India now, although only on the paper. I hope this ban is soon implemented in practice all across our country.
It is very likely that over the next decade, Nepal and other countries will follow India – and will make our planet a safe and green place to live for the next generations.
But till that happens, I will keep asking – BUT WHO CARES?
03 Tech Corner
This section consists of core technical stuff. Today we will be studying How to Test Drying Shrinkage of AAC Blocks. This will be in two parts, first is in this issue and second will be in the next issue of our journal.
Part I
The drying shrinkage test is lengthy, and its test procedure is given in IS code 6441 (part 2). As we have seen before, one of the critical aspects of AAC blocks is their drying shrinkage. The lesser the drying shrinkage, the better is the quality of the blocks. It is worth noting that the value of the drying shrinkage of an AAC Block is inversely proportional to its strength. The higher the strength of the block, the lower the drying shrinkage. Hence, with higher strengths, the possibility of shrinkage cracks in our masonry wall would be lower. Grade 1 of IS 2185 (Part 3) specifies that the drying shrinkage should not be more than 0.05%, whereas Grade 2 of the code specifies that the drying shrinkage value should not be more than 0.10%. With these two aspects in mind of Grade 1 and Grade 2, it becomes essential to test the drying shrinkage of the product carefully. Let’s look at the test procedure as given in code 6441 (part 2):
Apparatus for Length Measurement: This test is particularly sensitive and needs an exceptionally
Well-calibrated device to measure the specimen’s length. As the measuring procedure is unique, neither the regular scale nor a Vernier calliper can be used. It is a specially designed apparatus called a “Length Comparator”, which can measure the specimen with an accuracy of 0.003 per cent. We must remember that this test measures the change in length of the sample during drying.
Test Specimen:
Shape and size of Specimen: The drying shrinkage shall be determined by 40×40 mm cross-section prisms and length suitable to the measuring apparatus (but NOT less than 150 mm).
Length axis of the prism specimen shall be-
A) Perpendicular to the direction of rise, if the height of the block is less than 24 cm.
B) Parallel to the direction of rise, If the height of the block is more than 24 cm.
10 mm deep hole shall be drilled centrally in each surface of the prism to permit the introduction of spherically shaped gauge plugs which fit in the measuring apparatus.
Apparatus: A digital dial Gauge or any suitable measuring apparatus may be used to measure the length of the specimen with an accuracy of 0.003 per cent.
Gauge Plugs: It is a corrosion-resistant metal and shaped to ensure positive contact with the measuring device.
Immersion Tank: A suitable container shall be provided for the complete immersion of the specimen in water. (water temperature 27 ± 2c)
Storage room or Humidity chamber: A suitable room shall be provided in which the specimens can be dried at 27 ± 2c
Procedure: The prismatic specimen with gauge plugs at both ends shall be immersed in water till it attains a constant weight (not less than 72 hrs). Initially, the prism will rise to the surface if its bulk density is below 1 g/cm3. But after 2 hrs, the specimen is weighted down for complete immersion for the remaining 70 hrs or more if necessary.
Testing: After removing the sample from the water first length measurement shall be made as soon as possible, within half an hour. The specimen shall always be placed on the measuring unit in the same position. After the first reading, a second reading shall be taken with the specimen turned 90 around its length axis. If the two measurements differ, the average of the two readings shall be used.
Repeated length measurements shall be taken until the specimen has obtained constant reading – it may require 72 hrs or more up to 7 days.
Drying Shrinkage is calculated by
𝑺 = 𝐋𝟏−𝐋𝟐
𝐋 X 100
Were
S = Drying shrinkage,
L1 = First reading
L2 = final reading after the constant length
L = Original Length of the sample
What does the formula mean? This value S gives us the change in length of the test specimen.
But the change in length means what? The first length, L, is the test sample’s orig…How to Test Drying Shrinkage of AAC Blocks
The drying shrinkage test is lengthy, and its test procedure is given in IS code 6441 (part 2). As we have seen before, one of the critical aspects of AAC blocks is their drying shrinkage. The lesser the drying shrinkage, the better is the quality of the blocks. It is worth noting that the value of the drying shrinkage of an AAC Block is inversely proportional to its strength. The higher the strength of the block, the lower the drying shrinkage. Hence, with higher strengths, the possibility of shrinkage cracks in our masonry wall would be lower. Grade 1 of IS 2185 (Part 3) specifies that the drying shrinkage should not be more than 0.05%, whereas Grade 2 of the code specifies that the drying shrinkage value should not be more than 0.10%. With these two aspects in mind of Grade 1 and Grade 2, it becomes essential to test the drying shrinkage of the product carefully. Let’s look at the test procedure as given in code 6441 (part 2):
Apparatus for Length Measurement: This test is particularly sensitive and needs an exceptionally well-calibrated device to measure the specimen’s length. As the measuring procedure is unique, neither the regular scale nor a Vernier calliper can be used. It is a specially designed apparatus called a “Length Comparator”, which can measure the specimen with an accuracy of 0.003 per cent. We must remember that this test measures the change in length of the sample during drying.
Shape and size of Specimen: The drying shrinkage shall be determined by 40×40 mm cross-section prisms and length suitable to the measuring apparatus (but NOT less than 150 mm).
Length axis of the prism specimen shall be-
A) Perpendicular to the direction of rise, if the height of the block is less than 24 cm.
B) Parallel to the direction of rise, If the height of the block is more than 24 cm.
10 mm deep hole shall be drilled centrally in each surface of the prism to permit the introduction of spherically shaped gauge plugs which fit in the measuring apparatus.
Apparatus: A digital dial Gauge or any suitable measuring apparatus may be used to measure the length of the specimen with an accuracy of 0.003 per cent.
Gauge Plugs: It is a corrosion-resistant metal and shaped to ensure positive contact with the measuring device.
Immersion Tank: A suitable container shall be provided for the complete immersion of the specimen in water. (water temperature 27 ± 2c)
Storage room or Humidity chamber: A suitable room shall be provided in which the specimens can be dried at 27 ± 2c.
Procedure: The prismatic specimen with gauge plugs at both ends shall be immersed in water till it attains a constant weight (not less than 72 hrs). Initially, the prism will rise to the surface if its bulk density is below 1 g/cm3. But after 2 hrs, the specimen is weighted down for complete immersion for the remaining 70 hrs or more if necessary.
04 Upcoming Programs
We are glad to offer our new service, a complete heat recovery system for your plant. Do you know how much you heat you waste in your plant?
The condensate water below the Autoclave, the blowdown from boilers, the discharged steam from the autoclaves, the condensate from Steam line – there are many such places in our plant where we waste the valuable heat.
Please remember if you manage your heat well, your production cost will go down. In fact, we often say that we are not in the business of producing AAC blocks – we are in the business of managing heat inside of our plant.
Hence, we are offering this valuable service for your AAC plant.
By spending a small amount for this heat recovery system, you can bring down your fuel cost by more than 30%. This means the expense that you do for the heat recovery system will pay itself back in a short span of 6 to 9 months. This is a lifelong saving for you, reducing the production cost.
Please contact us if you want to install this heat recovery system in your plant.
Our email ID is ojasjoshi@aacindiainstitute.com
Conclusion
AAC India Institute looks forward to always providing decent content and pure ethical guidance in the industry. Our each word and letter that we exert is for the betterment and a genuine service of the industry.
In this issue of AAC India Journal, we started our journey from, why is it important to realize that we should realize and not simply know things. Because realization is a deeper, more experience-based concept than knowing.
As we move towards our CEOs visit to Nepal, we saw the cruciality of existence of AAC Blocks. AAC blocks need to be used with full force all over the earth. The importance of red clay bricks being eradicated from the construction industry is of high value not only for us but also for the planet. As we begin the tech corner, we saw in detail how to test drying shrinkage of AAC Blocks. Well, the part two of this will be coming in our next issue.
As we enter the concluding chapter, we take a tour towards the beating heart of any AAC plant. This is the most crucial part of AAC. If this is any mistake done, it can cost you a lot, and when I say a lot, I mean it to the fullest. The door closing process is often taken casually. But it definitely has great importance.
Stay tuned with AAC India Journal. We are committed to bring valuable content for you.
Ojas Joshi,
Co-founder,
AAC India Institute.
+918390541001
ojasjoshi@aacindiainstitute.com