Our Goal.
- Differentiate between tension and compression
- Observe how concrete mixtures affect structural results
- Including reinforcements
- Including reinforcements
- Summarize testing results
Materials
- Concrete
- Water
- Cup
- Plastic Wrap
- Hands
- Gloves
- Some form of a stick
- Measuring Cup
Procedure
- Perform slump test with mixture that is assigned to your group
- Divide both water and concrete amounts in half
- Document results in report
- Divide both water and concrete amounts in half
- Research slump tests and their results and compare to the observations you gathered
- Construct three concrete forms from cardboard
- Mix and pour concrete with and without reinforcements
- Document process
- Document process
- Test columns using pneumatic press
- Document results and process
- Document results and process
Slump Test.
When we were mixing our slump, we discovered that the mixture was thick unlike other groups around us. The first time we tried to remove the slump from the form, it did not work; however, after letting it sit a little while longer we ended up with a true slump. In our slump test, we got a true slump of ⅜”. We discovered that a true slump mixture is used to build strong concrete foundations for roads, bridges, etc. It is beneficial because it is the strongest mixture that can support these structures. We expect our mixture to perform very well.
Pouring
Testing
1- Air bubbles: Broke under 600 psi of tension.
Air bubbles do not provide reinforcement for the concrete, making it very easy to break under tension.
2- No air bubbles: Broke under 600 psi under compression
We all expected this test to do better than the one with air bubbles even though this was a compression test.
3- Small rebar: Broke under 1000 psi under compression
Concrete is better under compression especially with reinforcement. Since our reinforcement was wood, it got wet from the concrete when it was poured and broke much easier.
4- Large rebar: Broke under 900 psi under tension
We thought that the large wood rebar would perform better but again, since the wood was wet from the concrete, it was not as structurally sound as it could have been.
Our columns would have performed better if the rebar was not made of wood. Compared to the other groups who had regular rebar in their concrete, our columns performed basically the same. This is due to differences in concrete consistency.
Air bubbles do not provide reinforcement for the concrete, making it very easy to break under tension.
2- No air bubbles: Broke under 600 psi under compression
We all expected this test to do better than the one with air bubbles even though this was a compression test.
3- Small rebar: Broke under 1000 psi under compression
Concrete is better under compression especially with reinforcement. Since our reinforcement was wood, it got wet from the concrete when it was poured and broke much easier.
4- Large rebar: Broke under 900 psi under tension
We thought that the large wood rebar would perform better but again, since the wood was wet from the concrete, it was not as structurally sound as it could have been.
Our columns would have performed better if the rebar was not made of wood. Compared to the other groups who had regular rebar in their concrete, our columns performed basically the same. This is due to differences in concrete consistency.