Hello guys.I got a homework and seem like I am stocked.

a)What type of experiments should be done to find the relationship between the strength of concrete and water/cement ratio.

b)what will be the range of the water/cement ratio?

It would be great if you help.Thank you!

mix samples of differeing ratios.

after setting, I would do a compression test and a shear test on each mixture.

In the question I have some strenths and w/c ratios of some specimens and it is asking me about the range,molds?Also,How many specimens should be taken for each batch of concrete?

This is a question before we learn it,so really have some understanding problems.

For the experiments to verify water-cement ratio, go with Bob Pursley's idea. Water is necessary for the concrete to set, but too much water will weaken the concrete. Too little will make it unworkable, and will end up having voids. Plastisizers are usually added to improve workability without adding too much water.

Also, there is usually a slump test to check the workability of the concrete, in case the concrete stayed in the truck for too long and dried up, or too much water has been added by mistake.

We used to take 3 8-inch concrete cubes, and test one after 7 days. If it fails, we test another one at 14 days. If it still fails, we test the third at 28 days. If that still fails, we will do a field testing using a rebound instrument. If that still fails, chances that it will have to be demolished.

Procedures vary from country to country, and the code itself changes with time. In the US, ACI (American concrete institute) or ASTM determines the sampling and testing procedures. In Canada, it's probably the CSA standards. Today, cubes are no longer used, replaced by cylinders.

Hello! I can help you with your homework. Let's break it down:

a) To find the relationship between the strength of concrete and the water/cement ratio, you would need to conduct experiments. The goal would be to vary the water/cement ratio and measure the resulting strength of the concrete.

Here's how you can proceed with the experiments:
1. Plan your experiment: Define the range of water/cement ratios you want to test and the number of samples you will prepare for each ratio. Determine the available resources and time constraints.
2. Prepare the materials: Assemble all the necessary ingredients for making concrete, including cement, water, sand, and coarse aggregates.
3. Mix the concrete: Use the predetermined water/cement ratios and mix the concrete in batches. Make sure to follow the proper mixing methods and consistency requirements.
4. Cast the specimens: Pour the concrete mixture into molds to create standardized specimens. These can be cubes, cylinders, or beams.
5. Cure the specimens: Follow the curing procedures, which typically involve keeping the specimens moist for a specified period of time, usually 28 days.
6. Test the specimens: Use a concrete testing machine to measure the compressive strength of each specimen. Apply load gradually until failure occurs, and record the maximum load at failure.
7. Analyze the data: Plot the results on a graph to see the relationship between water/cement ratio and strength. This will help determine if there is a correlation between the two.

b) The range of water/cement ratios depends on various factors, such as the desired strength of the concrete, the type of cement used, and the specific application. However, for normal strength concrete, the water/cement ratio typically ranges from 0.4 to 0.6.

Keep in mind that your teacher or assignment guidelines may have specific requirements, so make sure to check any additional instructions provided. Good luck with your homework!