When I was working in a concrete batching plant before, I was the one who is managing all the tests as per plant quality control procedures like checking the moisture content of aggregates, flakiness index and elongation index, pH value of water and many more.
The most important test is the sieve analysis of aggregate, whether it is 20mm, 10mm, 5mm and 1mm sizes. The crucial thing is I have to do it every delivery of aggregate and as per the frequency of sieve analysis, which is written in this article frequency of tests.
As a quality engineer in the concrete batching plant, you have to see to it that the sieve analysis is done regularly, as per plant standards and quality procedures. There are certain purposes why you need to do this test, first, is you need to know if the delivered aggregate in your plant is a true size what I mean is “Is this really a 20mm size?” I will show how you will say that it is satisfactory or unsatisfactory and then how you will conclude that the aggregate you received is acceptable.
Second, is you have to determine the gradation or the distribution of aggregate particles by size, within a given sample in order to determine the concrete production requirements and the design of concrete mix.
You have to determine also the proportion of all-in aggregates within a sample to be used on concrete because if you will not get the appropriate proportion it may affect to the strength of your concrete, so it is really necessary to “do sieve analysis continually.”
Moreover, this sieve analysis procedure can be used by people who are working in the laboratory like government laboratory, private independent laboratory or even schools so this would help students make their “sieve analysis” done.
First here are the apparatus of the sieve analysis.
| S/N | DESCRIPTION | Uses |
|---|---|---|
| 1 | Sieves | Use to get the wt. of sample retained on each sieves and to determine the particle size distribution |
| 2 | Balance or Weighing Scale | Use to weigh the sample from dry and wet condition and the wt. of sample retained on each sieves |
| 3 | Mechanical Sieve Shaker | Use to shake the sample once it is inside the sieves |
| 4 | Oven or Hot plate | Use to dry the sample and maintain the temp. of 110 +/- deg. Celsius |
| 5 | Steel brush & Paint Brush | For removing entrapped material from sieve holes & cleaning |
| 6 | Sample Splitter | Use to reduce the sample to "mass test portion" |
| 7 | Spoons | Use to take sample from pan and for seggregating material |
| 8 | Pans | For handling samples |
Here is the full procedure on “How to do the Sieve Analysis of aggregate.”
1. Taking the representative sample. Take the samples with a minimum of 25kg. in the aggregates stockyard or storage bin by scattered basis, take from bottom, middle and top of the dumped aggregate, do not take from just one area. Place the sample in clean container. You can see in this video.
2. Reduce the sample to “Minimum Mass of Test Portion.” There are minimum masses that you would need to take corresponding to each size of aggregate that you are going to do sieve analysis. This time we’re going to use 20mm aggregate, so we will reduce the sample to 2 kilograms (minimum weight) but you can make it more than 2kgs as long as you will follow the process. There are two ways how to reduce the weight of the sample, one is by using the riffle box which you can see it on this video which I almost can’t speak.. haha lol! “How to reduce sample using riffle box” and the other by manual splitting called “Quartering Method” which is also a very simple way. See photo below of a sample quartering.
3. Washing the sample. Once the sample has been reduced to 2 kilograms or to a “minimum mass” then wash it with a clean water or faucet water, make sure it is thoroughly cleaned before oven drying. Weigh the sample, mark as mass at wet condition Mass 1 (M1).
4. Oven dry the sample. Oven dry it for 24 hours before you will conduct sieve analysis, but make sure weigh the sample and record before you put the sample inside the oven, mark as sample at moist condition as per Item 3. Put the oven to a temperature of 110 degree Celsius. Once the sample is oven dried, weigh the sample, mark as Mass at Dry condition, or M2.
5. Sieving the sample. The sieves number that you will use in the 20 size aggregate samples are 37.5 mm, 20.0 mm, 14.0 mm, 10.0 mm & 0.075 mm. Place the bigger size of sieve on top of smaller and in order from from top to bottom. And then put the dried sample on topmost sieve (37.5 mm) be careful on placing the sample to avoid throwing out of some pieces of aggregate that would create error on the calculations. Put the sieve on the sieve shaker or you can make sieve shaking manually for 10 minutes long.
6. Weight the retained material on sieves. You can weigh now the material retained on each sieve. But make sure you remove the trapped material from the holes of the sieve, remove by steel brush or paint brush accordingly. You can then weight now and include the material to the mass retained and record it.
7. Calculations. Once you have finished recording the mass retained samples. You can easily calculate the percentage retained and cumulative percentage retained. See below calculations.
So in the above calculations the result of cumulative percent passing is within the limits, in the first place we can initially conclude that the 20mm size aggregate sample as a representative of the delivery is acceptable.
And the final conclusion can be obtained from the result of “material finer than a 75µm in percent.” The standard say’s “the course aggregate shall have not less than 5 percent of material passing 75µm sieve.” So therefore, the 20mm size aggregate delivered in this instance is satisfactory.
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Mr Noel, thanks for your education, am working as lab technician and currently working especially concrete everyday, what is the spec for the stone base and what size of sieves should I use? How do I calculate ten percent fines?
Mr. Noel please let me know how to design concrete with three types of aggregate 3/4,3/8,3/16.
Thank you, if you have any videos clips about all 6 concrete test please share it with friends.
I don’t have it yet, these test are done in the laboratory.
Please answer me, what’s the error that we could do when are we testing this procedure?
Do not take the samples from one point. And you should follow the procedure from the standard.
I don’t care if it was copied from a Standard; Standards have to be copied. I am grateful Noel for posting procedure of conducting “basic experiment’ in civil engineering. I am also a Civil Engineer and I often need to access to such basics in the course of my duty. Thank you Noel
Hello Mr. Noel! Good day. Thank you very much for this site, we learned a lot from you. You are so generous. GOD bless you more.
Hi! Thank you Ronualdo. God bless you too..
I love this site, please continue writing. It refreshes my knowledge. Also, I like how you deal with etmasonjr. I believe you are good in dealing problems on site, there are lots of people who delays activities.. a personality of mason is a good example.
Thanks. I will write more informative articles, don’t worry. Ya, we should know how to handle things around us. Thanks for your concern.
Haha tell that to thousands and not only thousands maybe millions who wrote like this on the internet. But this is my personal and genuine experience I am not ashamed to share. If you are willing to share your knowledge here I will pay you just let me know.
Mr Mades. do not just copy and publish. You must have your own patented copy. If you worked in a batching plant, then I will tell you I am not that cheap. I was in UAE and worked for the biggest flagship project. However these frequency that you had shared are very wrong. The UAE adopts more frequently BS standard and DIN standard. Do not insist that you have your own standard like UAE standard. Anyhow, I do not intend to argue with you in what you called sharing idea. if I share, I will make is sure that all are true and correct and even I have to mention where standard it came from. What I ask you is that you may have the purpose of helping but the help you have are fictitious and non existing. If your claims are true and correct. then let me know what standard it came from. I have full copies of BS, ASTM,ACI,DIN. CS, BIS, AREMA,. I am not interested to earn by telling my readers the wrong and unsupported data.
That is my own word :). Wow! Mr. Mason do not underestimate the people who work in a Batching Plant. I worked in a batching plant for over 6 months, but I am proud because I really learnt a lot. And I have known one person that worked in a Batching Plant who is earning a big money every month, 80,000 Dirhams I guess. Tell me how much you are earning before you had looked down the people who work in a BP. In your statement, you had just depicted who you are.
If you really wanted to know what standard I used, it was BS standard in this article for your clear information.
This is a reproduction copy of ASTM C33. Can you not make your own without copying to the copyrighted standards? It make you popular by deceit.
Hahaha Sorry Mr. Emilio Mason. I learned that when I was working in a concrete batching plant. I am just sharing the knowledge I gained haha. If you have knowledge, I challenge you to share here. In fact, I am searching for a writer on this blog. If you are willing to make extra income because I will pay every time you write for me. Just let me know my friend. Please read this for more https://www.qualityengineersguide.com/post-your-idea-about-quality-engineering.
You can just copy it and paste. Welcome…
be ashame my friend. You are doing a copyright infringement.
I want to have a soft copy of this article. Thanks in advance.