Backyard Greenhouse with Pervious!
This just in:
A backyard greenhouse with a pervious concrete floor that lets in the sunshine and lets out the water! Check out the video below:
The backyard greenhouse will function as much as a plant habitat as a personal retreat. I understand a chair, and a reading light will go in there, so that the owners can enjoy the plants and sunshine even in the chillier winter months. That sure looks cozy! What do you think?
Crazy Installations- a backhoe for your hard to reach places?
Perhaps it wasn’t the most efficient installation technique..... 
PIP-CAT Scans of Pervious Concrete
Dr. Neithalath’s presentation was on his research on the effect of mix design on pore structure and infiltration performance. Currently, the state of the art is rife with trial and error which ends up, at worse, with pavement failures, and best, an inconsistent mix. He wants to really understand how different aspects of the pervious concrete mix affect the different performance attributes. In this way, he wants to be able to dial in a pervious mix, with the exact attributes required for the ideal functioning of the installation.
The key feature of pervious concrete is the porosity, which we are all familiar with. Permeability is linearly related to porosity, and while that is obvious, it forms a helpful and fundamental baseline for 1 aspect of pervious concrete as a hardscape. Other aspects of pervious concrete are less well understood and they include types and seriousness of particle retention or clogging; oil retention, as some are considering pervious concrete as a bio-filter; strength and fracture, for structural considerations; as well as how mix design informs the size, type and structure of the voids. Dr. Neithalath is working to understand how all of these factors come together to form computational performance models for consistent designable pavements. In turn that would create a matrix of variable that could be controlled to create very precise mix designs for producers and installers.
My favorite part of Dr. Neithalath’s presentation was the video he presented of a pervious concrete cylinder in a CATscan, going all the way throughout, such that the void patterns were completely observable. Below you can see the video. I found the whole thing hypnotizing. What do you think?
To see more about Dr. Neithalath’s work, you can go to his faculty page here.
CSU East Bay has a new Concrete Testing Lab
David had taken some samples at a recent pour and wanted to get them tested. Fortunately, Cristian Gaedicke, Concrete Materials Professor at CSU East Bay, had a new lab with brand new equipment to try out. We headed over for a tour and a testing field trip. Below are some photos of our compression test. We also did a void and density test but I hadn’t started taking photos at that point. Below you will see Cristian sawing off the top of the samples, to make them flat for capping.
Next, we capped the 2 samples in sulfur, which makes them totally -perfectly- flat. That is also the way we have tested all of the rest of our samples, so we can keep our data consistent. The sulfur is heated in an industrial-type crock pot, under a hood for total ventilation. The green corner piece is the mold that sets the final edge so it is exactly at 90 degrees. 
David stirs the melting sulfur chips. Since the lab was pretty new, the sulfur pot hadn’t been used yet!
Once the 2 samples were capped, they were put into the crush test. This measures the PSI load of the sample. Below you can see the sample in the crushing machine. 
I am taking copious notes, while Cristian is making sure the machine works. 
David is also taking notes as the test is being set up.
David and Cristian compare notes, and discuss the results. They review the smashed cylinders, seeing the pattern and reviewing paste adhesion in this mix. 
David is very happy with the results!
You can see that both cylinders had very consistent crush pattern.
The whole crew, minus the photographer! 
Stormwater Sleuthing - Episode 2 - Palo Alto
What did you think? Do you have a Stormwater Sleuthing location (in the Bay Area) that you would like David to investigate the next time it rains? Let us know in the comments below or contact us here. Thanks!
Stormwater Sleuthing - Episode 1
What did you think? Do you have a Stormwater Sleuthing location (in the Bay Area) that you would like David to investigate the next time it rains? Let us know in the comments below or contact us here. Thanks!
I Spy Videos and Pervious Concrete
We have created an ISPY video on the World's Longest Driveway! Can you find all of the items listed below? Feel free to send this link to the keenest eyes you know. Use the full screen option, to catch all the great details! It took me 3 tries to catch everything - how many did it take you? A list of the items is below the video.
Egg carton, Buzz Lightyear toy, V8 bottle, Clipboard, Rubber rat, Hammer, Talking lizards, Santa hat, Manila envelope, Wall-E figurine, Hackeysack, Tennis shoe, Hardshell glasses case, Blonde doll in a pink dress (polly pocket), Rubber chicken, Stack of CDs, Newspaper, Pliers, Roll of tape, Magnifying glass, Padlock and key, The Lost World paperback book, Stuffed animal monkey, Spray bottle & Bar Simpson doll
How many objects did you catch the first time?