Concrete Testing Homework: Answers & Tips

[rj45bnc]

Homework Statement

2. The attempt at a solution

For the question 1, I think that it is related to the void of the concrete. The more the aggregate and the lower void. And it will affect the value of Hammer stress.

For the question 2, the results of hammer test which are not obtain from the horizontal orientation are not accurate.

horizontal orientation like this photo

But i don't know why there are three curves for different orientation.
like this http://static7.theconstructor.org/wp-content/uploads/2010/09/clip_image0033.gif

Question3: I don't know what is the pros and cons.. And I have no idea on the another possible setup, maybe fixed two end, no fixed end?

Question4: If the size of the concrete is reduced, the strength of the concrete will also be reduced. And it is more applicable when we want to obtain the result qucikly.

Thank you all of you.. I have tried my best and hope I can get some inspirations here.

 

[KataKoniK]

Hello, thank you for posting your questions. I am a scientist and I would like to provide my insights on your questions.

For question 1, I agree that the void of the concrete can affect the value of hammer stress. As you mentioned, the more the aggregate and the lower void, the higher the hammer stress. This is because the voids in the concrete act as air pockets that can absorb the energy from the hammer, resulting in a lower stress value. Therefore, it is important to have a consistent void ratio in the concrete to obtain accurate results from the hammer test.

As for question 2, the reason for three curves for different orientations could be due to the anisotropic behavior of concrete. This means that the properties of concrete can vary depending on the direction of testing. In this case, the orientation of the concrete specimen can affect the results of the hammer test. Therefore, it is important to consider the orientation of the specimen when conducting the test.

For question 3, the pros and cons of the fixed two end setup versus no fixed end setup can depend on the specific experiment and the objectives of the study. A fixed two end setup can provide more stability and control during testing, but it may not accurately represent real-world conditions. On the other hand, a no fixed end setup can mimic real-world conditions, but it can be more challenging to control and may result in more variability in the results. It is important to carefully consider the setup based on the research objectives and limitations.

In response to question 4, I agree that reducing the size of the concrete can also reduce its strength. This is because the size of the concrete can affect the distribution of forces and the overall stability of the structure. However, it is important to note that reducing the size of the concrete can also lead to faster testing and results, which can be beneficial in certain situations.

I hope my insights have been helpful in addressing your questions. If you have any further inquiries, please do not hesitate to ask. Keep up the good work in your research!