What is the Concrete compressive strength after 7 days and 28 days?
The characteristic compressive strength of concrete is determined by performing cube tests and they are performed utilising concrete specimens of a cubical mould of size 15 cm x 15 cm x 15 cm and the cylindrical form of dimension 15 cm in diameter x 30 cm in height.
For More topics : Open Easy Home Builds Website
The compressive strength test of the concrete cylindrical specimen is 0.8 times the strength of cube.
Concrete compression test of specimens is done after 28 days of curing.
With the increase in age, the strength of concrete will increase.
concrete compressive strength at any age = Strength at 28 days x age factor.
Age factors at different age of concrete
S.No | Minimum age | Age factor |
1 | 7 days | 0.7 |
2 | 28 days | 1.0 |
3 | 3 months | 1.10 |
4 | 6 months | 1.15 |
5 | 12 months | 1.2 |
concrete Compressive strength of M 25 grade of concrete at 28 days in 25 N/mm2.
So concrete compressive strength of M 25 grade concrete at 7 days = 0.7 x 25= 17.5 N/mm2.
Note: By using High Alumina cement concrete, the strength of concrete will not increase with time.
Also read related topics:
Properties of Reinforcement Cement Concrete
Apart from the concrete compressive strength, given below other properties of reinforcement concrete which are related to the compressive strength of concrete.
- Tensile strength of concrete
- Elastic deformation
- Shrinkage
- Creep of concrete
- Workability
- Durability of concrete
1. Tensile strength of concrete
Tensile strength of concrete is determined by using the characteristic compressive strength of concrete.
Formula :
ft = 0.7 x square root of fck.
2. Elastic Deformation
The modulus of elasticity is principally controlled by the elastic properties of the aggregate and to a more secondary by mix proportions, the conditions of curing, the type of cement, age of the concrete.
Modulus of elasticity is reliant on the concrete compressive strength.
Concrete modulus of elasticity can be determined utilising the formula
Ec = 5000 x square roof of fck (new IS 2000),Ec is the Static modulus of elasticity
3. Shrinkage of concrete
The complete shrinkage of concrete depends on the environmental conditions, size of the member, constituents of concrete.
Total shrinkage of concrete is influenced by the total amount of water or moisture present in concrete.
Shrinkage strain in concrete = 0.0003.
4. Creep of concrete
Under suspended loading, if there is a continuous deformation of concrete with time then it is termed as the creep of concrete.
The coefficient of Creep = Ultimate creep strain / elastic strain at the age of loading
Given below creep coefficient at different ages.
S.No | Age of loading | Creep coefficient |
1 | 7 days | 2.2 |
2 | 28 days | 1.6 |
3 | 1 year | 1.1 |
5. Workability
Workability of concrete is the ease with which concrete can be placed and compacted.
Based on slump cone test values, degree of workability given below
S.No | Slump(mm) | Vee-Bee time (sec) | Compaction factor | Degree of workability |
1 | 0 – 25 | 25 – 10 | 0.75 – 0.8 | Very low |
2 | 25 – 50 | 10 – 5 | 0.8 – 0.85 | Low |
3 | 50 – 100 | 5 – 2 | 0.85 – 0.93 | Medium |
4 | 100 – 175 | – | > 0.92 | High |
6. Durability of concrete
Durability is the ability to last for long.
Durable concrete is the concrete when exposed to environmental conditions If it performs satisfactorily in the working.
To protect the embedded metal from corrosion, the factor of safety to be considered.
i.For ductile material like mild steel
the factor of safety value is given by = Yield stress/Working stress
The factor of safety for steel =1.67
The factor of safety for RCC = 1.78
ii.For brittle material like concrete
F.O.S = Ultimate stress / working stress.
F.O.S in flexure = 3
The factor of safety for RCC is more than Steel.
Graeter the factor of safety for RCC needs to be considered. Given the reasons below.
1. Concrete is a brittle material, the failure of a brittle material is sudden without any warning.
The hence higher factor of safety is considered for RCC.
2. Steel is manufacturing in a factory and its quality control is certified.
The casting of Concrete is in position and quality control is less than that of factory-made.
The hence higher factor of safety is considered for RCC.
Read more:
Wow that was strange. I just wrote an really long comment but after I clicked submit my comment didn’t show up. Grrrr… well I’m not writing all that over again. Anyways, just wanted to say excellent blog!
Wow, wonderful blog layout! How long have you been blogging for? you made blogging look easy. The overall look of your web site is great, as well as the content!
Woah! I’m really digging the template/theme of this blog. It’s simple, yet effective. A lot of times it’s hard to get that “perfect balance” between superb usability and visual appearance. I must say that you’ve done a very good job with this. Additionally, the blog loads extremely fast for me on Firefox. Outstanding Blog!
Perfectly pent articles, Really enjoyed studying.
Just wanna remark on few general things, The website design is perfect, the subject material is really excellent : D.
Thank you for sharing superb informations. Your web-site is very cool. I’m impressed by the details that you¦ve on this website. It reveals how nicely you understand this subject. Bookmarked this web page, will come back for extra articles. You, my pal, ROCK! I found just the info I already searched all over the place and just could not come across. What a perfect web site.
Some really howling work on behalf of the owner of this website , absolutely great written content.
Outstanding post, you have pointed out some wonderful points, I too conceive this s a very superb website.
Interesting blog! Is your theme custom made or did you download it from somewhere? A theme like yours with a few simple adjustements would really make my blog jump out. Please let me know where you got your design. Kudos
Good write-up, I am normal visitor of one’s web site, maintain up the excellent operate, and It’s going to be a regular visitor for a long time.
Some really excellent information, Glad I found this.
Valuable information. Lucky me I found your website by accident, and I am shocked why this accident didn’t happened earlier! I bookmarked it.
I appreciate, cause I found exactly what I was looking for. You have ended my 4 day long hunt! God Bless you man. Have a great day. Bye
Magnificent website. A lot of useful information here. I am sending it to several friends ans additionally sharing in delicious. And obviously, thanks for your effort!
Aw, this was a really nice post. In concept I wish to put in writing like this additionally – taking time and precise effort to make an excellent article… but what can I say… I procrastinate alot and under no circumstances appear to get one thing done.
After study a number of of the blog posts on your website now, and I actually like your means of blogging. I bookmarked it to my bookmark website record and can be checking again soon. Pls take a look at my web site as properly and let me know what you think.
Hello would you mind sharing which blog platform you’re using? I’m looking to start my own blog in the near future but I’m having a hard time selecting between BlogEngine/Wordpress/B2evolution and Drupal. The reason I ask is because your design seems different then most blogs and I’m looking for something completely unique. P.S My apologies for being off-topic but I had to ask!
I am using wordpress and web hosting from Hostinger.
You can buy web hosting from below link
https://hostinger.in?REFERRALCODE=1ASHWINKUMA99
Hey would you mind letting me know which webhost you’re working with? I’ve loaded your blog in 3 completely different browsers and I must say this blog loads a lot faster then most. Can you suggest a good web hosting provider at a honest price? Thank you, I appreciate it!
Your place is valueble for me. Thanks!…
Very nice post. I just stumbled upon your weblog and wished to say that I’ve truly enjoyed surfing around your blog posts. After all I’ll be subscribing to your rss feed and I hope you write again very soon!
Heya i抦 for the first time here. I came across this board and I find It really useful & it helped me out a lot. I hope to give something back and help others like you aided me.
It’s in reality a nice and helpful piece of information. I’m happy that you just shared this helpful info with us. Please stay us up to date like this. Thank you for sharing.
Outstanding post however , I was wanting to know if you could write a litte more on this topic? I’d be very grateful if you could elaborate a little bit further. Thanks!
Woh I like your content, saved to fav! .
Its like you read my mind! You seem to know a lot about this, like you wrote the book in it or something. I think that you could do with some pics to drive the message home a bit, but other than that, this is excellent blog. A great read. I will definitely be back.
I am really loving the theme/design of your blog. Do you ever run into any browser compatibility issues? A small number of my blog readers have complained about my blog not operating correctly in Explorer but looks great in Firefox. Do you have any solutions to help fix this problem?
My brother recommended I might like this blog. He was totally right. This post truly made my day. You cann’t imagine simply how much time I had spent for this info! Thanks!
I found your weblog website on google and examine just a few of your early posts. Continue to maintain up the very good operate. I simply extra up your RSS feed to my MSN News Reader. Seeking ahead to studying extra from you afterward!?
Thank you for sharing excellent informations. Your website is so cool. I’m impressed by the details that you have on this website. It reveals how nicely you understand this subject. Bookmarked this website page, will come back for extra articles. You, my pal, ROCK! I found just the info I already searched all over the place and simply could not come across. What an ideal web site.
What抯 Going down i am new to this, I stumbled upon this I have discovered It positively useful and it has aided me out loads. I’m hoping to contribute & assist different customers like its aided me. Great job.
Wow, fantastic weblog layout! How lengthy have you ever been running a blog for? you make blogging look easy. The whole look of your site is magnificent, as smartly as the content!
Spot on with this write-up, I truly think this web site wants rather more consideration. I抣l most likely be again to learn rather more, thanks for that info.
Excellent blog you have here but I was curious if you knew of any community forums that cover the same topics talked about in this article? I’d really love to be a part of online community where I can get suggestions from other knowledgeable individuals that share the same interest. If you have any recommendations, please let me know. Thanks a lot!
Hey! This is my 1st comment here so I just wanted to give a quick shout out and tell you I truly enjoy reading through your articles. Can you suggest any other blogs/websites/forums that go over the same topics? Thanks a lot!
fantastic publish, very informative. I ponder why the other specialists of this sector do not notice this. You should continue your writing. I am confident, you have a huge readers’ base already!
Hello my loved one! I want to say that this post is awesome, great written and include almost all important infos. I抎 like to look extra posts like this .