20 Time Final Post

My 20 Time project was about converting regular concrete into pervious concrete. I was successful in making a slab of concrete porous by spraying it with chemicals. Gypsum and vinegar were the two chemicals that worked and I have submitted my project to Google Science Fair. Over the summer, I will continue to work on my project by finding the most effective mixtures of gypsum and vinegar for use on concrete. I will also test the structural stability of treated concrete blocks.

Gypsum I tested on the concrete in an ~1/5 solution in water

The TED Talk I gave in class about my project

I would say my talk went quite well. Although I stumbled a lot at the start, once I got on track, my speaking got smoother and I was able to articulate my thoughts in a way the audience could understand. I thought I would need my notes, but I ended up just using the images as cues. That being said, I was still very nervous beforehand because I had only written the script the night before. I also had no words in my slideshow, so there were no hints to read off of without looking down at my notes.

Even though I was more nervous before this presentation than before my "What on Earth Evolved?" Presentation, I felt this one looked more professional overall. This is because I had more true passion for what I was talking about, allowing me to walk around and look relaxed. However, I may have been unclear in some parts because during the questions, some people were asking me things that I thought I had answered while talking. Overall, this was a slight improvement from my Tiktaalik presentation, but a definite improvement from my public speaking skills at the start of the year.

20 Time Individual Reflection

For my 20 Time project, I challenged myself to develop a chemical which can make regular concrete pervious. My goals were realistic and although I did stray from my timeline, I still finished. My plan was to spread the experiment over 6 weeks, but I ended up buying my materials just 2 weeks before the deadline. As soon as I got my materials though, I created a plan to make sure the testing gets done before the project is due.

I think my plan was a success. Out of the 13 chemicals I tested, about 6 worked well. However, I only chose to retest 3 because the others were unrealistic to use in the real world or weren't very efficient. When retesting, I put a metal can (open on both sides) and sealed the base with wax. I then poured water into the can so it's resting on the concrete. Some water did drip through the sealant, but I watched the apparatus to make sure water wasn't cheating by entering the bucket from the sides rather than from through the concrete. One of the chemicals, gyspum dissolved in water, yielded 55ml of water. Considering that some of the 250ml had dripped outside of the bucket, the treated concrete had about a 30% efficiency.

I came into this project expecting basically nothing. I knew my idea was great, but I doubted that it would work. But when I got positive results, I realized that I might be on to something. I decided to team up with a friend from my old school and submit the project to Google Science Fair. The project is due in a week, and we are almost done with our written essays. If I have free time, I might put together a video with all the images and footage I captured while experimenting. In conclusion, I feel that my 20 Time project was really fun as well as successful, but I am still at the tip of the iceberg. Although the due date for Google Science Fair is coming up soon, I will spend some time this summer developing concoctions of gypsum and vinegar (my highest performing chemicals) and testing them.

Testing!

I finally started testing the chemicals last week. Yay! I know I'm about a month off schedule and that the project is due in barely a week, but I made a plan last week. I've stayed on track for the past 6 days. Here is what the past 6 days have looked like:

Chemical	Spray/Soak Time	Test Time	Amount of Chemical	Amount of Water Sprayed	Amount of Water Collected	Notes	Retest?
Control (nothing)	9pm 4/26-7pm 4/27	7:30-8:00	N/A	250ml	0
Sakrete	9pm 4/26-7pm 4/27	7:25-7:55	500ml	250ml	0	Edges crumbly and green on second day
Gypsum	9pm 4/26-7pm 4/27	8:04-8:34	250ml (60ml gypsum+250ml H2O)	250ml	~30ml (retest needed)	Retest needed	Yes
Alcohol and Burn	7pm 4/28 (but n/a)	9:41-10:11	500ml	250ml	~20ml	250ml spray then burn; 250ml spray while burning. Surface hot	No; unrealistic
Vinegar	7:15pm 4/28-9pm 4/29	9:13-9:43	250ml	250ml	~40ml	Bubbling a little after sprayed chemical	Yes
Ammonia	6:30pm 4/28-9pm 4/29	9:09-9:39	250ml	250ml	0	Poured instead of sprayed chemical
Hydrochloric Acid	3:45pm 4/30-4pm 5/1	4:33-5:03	250ml	250ml	~40ml	Foamed up yellow/green when poured chemical; Poured because of danger	No; unrealistic
Bleach	3:30pm 4/30-4pm 5/1	3:59-4:29	250ml	250ml	50ml		Yes; a lot of H20
Hydrogen Peroxide	3:20pm 4/30-4pm 5/1	3:56-4:26	250ml	250ml	~10ml	Greenish square formed in center; Fizzing/bubbles when spraying chemical	No; not enough
Sulfuric acid	3:20pm 5/2-4pm 5/3	4:20-4:50	250ml	250ml	15ml	Bubbling/fizzing when sprayed chemical	No; unrealistic
Coke	3:30pm 5/2-4pm 5/3	4:54-5:24	250ml	250ml	20ml
Calcium Chloride	3:15pm 5/2-4pm 5/3	4:23-4:53	250ml	250ml	10ml	White residue on concrete after 24 hours	No; unrealistic
Seawater	6pm 5/4-4:30pm 5/5	4:33-5:03	250ml	250ml	0	Salt residue on tub after 24 hours
Dry Ice	6pm 5/4-4:30pm 5/5	4:30-5:00	5 lb	250ml	0	All dry ice gone after 24 hours

Basically, I spray the concrete with 250ml of chemical one day and let it soak until the next day afternoon. After those ~24 hours, I put the slab on top of a bucket and spray it with 250ml of water. I let the water sit for 30 minutes, then measure how much has dripped through the concrete and into the bucket below.

There may be a few flaws in this experiment, including water seeping into the bucket from the edges of the slab and differences in amount of water actually landing on the concrete. To remedy this I will be retesting some of the highest performing materials. Here are my retest results:

Chemical	Spray/Soak Time	Test Time	Amount of Chemical	Amount of Water Poured	Amount of Water Collected	Notes
Gypsum	5pm 5/6-6pm 5/7	6:13-6:43	250ml (60ml gyspum)	250ml	55ml	Used crayon wax as sealant; no visible drip into bucket from sides
Vinegar	5pm 5/6-6pm 5/7	6:22-6:52	250ml	250ml	30ml	Used candle wax as sealant; no visible drip into bucket from sides
Bleach	5pm 5/6-6pm 5/7	6:59-7:29	250ml	250ml	50ml	Used candle wax as sealant; no visible drip into bucket from sides