Any tips or pointers greatly appreciated. Papers, documents, own findings, etc. are all welcome.
I do not think that there is an optimum ratio, since this depend on many factors like;
i. Required slump,
ii. required strength,
iii. Maximum aggregate size, and
iv. Cement content.
The optimum ration depends on too many factors. It is really volumetric, but concrete is better batched by mass. The characteristics required of the concrete will determine the appropriate ratio. A starting point is to use a near maximum density grading of the materials.
Thank you both Saad and Gordon for your prompt answer. I agree with your comments. The reason I asked is that one of the reviewers to a paper has stated that the normal range for the ratio of fine aggregate to coarse aggregate is 0.45 to 0.50, and I wanted to know where this was coming from?
I also agree with Saad and Gordon. Nobody can say that there is an exact or certain ratio limitation between the fine and coarse aggregates. It s depend on so many factors ofcourse. Moreover, some conventional concrete maybe need 0.35-0.55 fine/coarse aggregate ratio limitations, on the other hand, in the self compacting concrete design as a special concrete we have to use the more fine materials like fine aggregate (0.65 by volume in total mix), powder ect, and less coarse materials like coarse aggretgate (0.35 by volume in total mix), fibre addition ect.
There is no optimal ration stablished, it depends also on the distribution of particles of both the fine and the coarse aggregate. There is a procedure called Emptyness Percent wich gives an idea of the optimal percentage we could use. But as I sayd before, these percents are related to our types of aggregates.
Thank you Nusret and Enzo. Your clarifications are very helpful. I agree with your statements. Since yesterday, I did find some papers that actually use ratios ranging from 0.35 to 0.60 - depending on the mix used. One such paper is:
Influence of Crushed Coarse Aggregates on Properties of Concrete, by I. B. Muhit, S. Haque, Md. Rabiul Alam.
Once again, many thanks. And any publications on the topics are welcome.
Thank you Smitha. I will consult the paper and propose it to my PhD student. It does sound interesting, especially that it deals with both normal and high performance strength concrete.
For different mix design the optimum ratio of fine aggregate to coarse aggregate can be changed. It depends to variety of factors considering mainly fresh and hardening phases of concrete. Even for hardening phase not only the mechanical properties of concrete such as; strength, Ec, drying shrinkage, creep,.. need to be considered, but also the durability of concrete must me considered for short and long term ages too.
Does anyone know what is the ideal (optimum) ratio of fine aggregates to coarse aggregates in a standard concrete mix? - ResearchGate. Available from: https://www.researchgate.net/post/Does_anyone_know_what_is_the_ideal_optimum_ratio_of_fine_aggregates_to_coarse_aggregates_in_a_standard_concrete_mix [accessed Nov 27, 2015].
Many thanks Ali for your answer. It is really very helpful. It seems that there are simply too many parameters that can affect the answer.
I am finding more papers on the topic, which is good.
One of my masters students did some work on it. We have increased sand to total aggregate volume ratio from 0.35 to 0.55. It was observed that the compressive strength of concrete is increased with the increase of sand to total aggregate volume ratio. The paper has been submitted in ASCE Mat J. To find the optimum value, we have to increase it beyond 0.55.
Tarek, this is very interesting. I certainly look forward to reading your paper once it has been published. Incidentally, it my master student too who is working on this programme. When will your paper be out?
dear Messaoud Saïdani
The ratio depend on the grading of the fine and coarse aggregate
- Badges
- Science topic