Commodore Park in San Jose is now ready for a Frisbee!

San Jose’s newest park features a colored pervious concrete path going around the park! And it is finally open! Santa Clara Valley Urban Runoff Pollution Prevention Program honored the City of San José with an award for Commodore Park’s Site Design and Low Impact Development for Storm Water Pollution. The award recognizes the park's low-impact development features that are helping to protect water quality by filtering stormwater through plants and soil, while allowing stormwater to infiltrate into the ground to help replenish groundwater. 

Time to load up the family, grab the frisbee and explore this great new space. It has children’s playground equipment, adult’s exercise equipment, picnic areas and a grassy expanse, all accessed by ADA friendly pervious concrete. It is a lovely space to spend the day.

If you head out there, please send us photos of you enjoying the park! We will post them here! :)

White Hill Middle School Gets a Brand New Courtyard

White Hill Middle School up in Marin County is the first school to put in polished pervious concrete! WRNS Studio designed it in the main courtyard area between classrooms as well the shaded amphitheater style steps, shown below.

The finishing touches were just getting completed as teachers were prepping classrooms in anticipation of classes starting. It was very exciting!

We were able to get this fantastic design installed with the help of a dedicated team of design professionals. Joel Williams and Pauline Souza from WRNS Studios were invaluable as design advocates for pervious concrete from the beginning of the project. Mike Hastings, from Sherwood Engineering, was the civil on the project, and his collaboration and cooperation on the technical aspects enabled us keep momentum going. We look forward to working with both of these firms in the future, for more pervious concrete projects!!

And here is our favorite shot - a close up of the nice tidy finish, and the subtle color variations in the polished finish the school administrators were looking for.

Photos of the Finished Valley Oak Co-Housing Project

As the landscaping grows in, and the people move in, the pervious concrete hardscapes just get better looking! Check out the below photos for a more updated view of Evolution Paving’s Architectural Fine Pervious Concrete that we placed at the Valley Oaks Co-Housing project in Sonoma.

Tell us what you think!  Do these look like livable hardscapes to you? Honestly, I just want to pet that puppy! :)

Hard to Reach Installations - a backhoe for your hard to reach places?

Have you ever found yourself in a pinch, not getting material to the farthest corner of a pour? Have a backhoe handy? Exactly! See how we did it on a residential pervious pour in the hills of Palo Alto.

Perhaps it wasn’t the most efficient installation technique.....

UC Berkeley's newest path is pervious

The Simons Institute for the Theory of Computing has a new home in the Melvin Calvin Laboratory building on UC Berkeley’s campus. And skirting the southwest edge is a new polished pervious concrete path! The next time you find yourself on campus, I hope you bring some water and pour some out on their new pervious path!
This is where the path is adjacent to Optometry Lane.

Sausalito Fairytale: Harrison Park

Harrison Park, a tiny oasis in the residential area of Sausalito boasts one of the only playgrounds in the city, as well as a pervious concrete path!  Take a look around and the next time you are there, check out Harrison Park in the hills of Sausalito!!

Have you been? What do you think?  Let us know in the comments below:

Stormwater Sleuthing - Episode 2 - Palo Alto

David Liguori is back in the field, this time comparing a long sloped asphalt driveway with a neighboring long and sloped pervious concrete driveway during a rainstorm last year.

Here Dave compares 2 sloped driveways in a rainstorm - one asphalt, and one pervious concrete. It is the great runoff comparison!

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!

USGBC Greener Builder - a fantastic conference!

This was originally posted June 19, 2013.

Lauren Wray, our Director of Marketing, attended the USGBC’s Greener Builder Conference last week. Apparently the Greener Builder Conference is even GREENER then the Green Builder Conference that occurred in November! This conference did not disappoint. From the opening panel, pictured below, featuring Jeffrey A. Birdwell, Michael Deane, Kevin Hydes, Kirsten Ritchie and moderated by Cliff Brewis, the focus was on leading edge sustainability, and strategies to get regenerative planning and innovation into the building industry.

There were good options for every panel, but as pervious concrete sub-contractors, we went to the subcontractor panel, hosted by John Home and Jeff Swinyer of Rudolph and Sletten, pictured below.

Lauren, pictured below, was interested in the drive toward clear performance specs to allow for differentiation at the sub-contractor level. As a pervious concrete subcontractor, we differentiate ourselves with our embrace of leading edge technologies for mix design and installation. Unfortunately, many current specs don’t reflect the progress in the installation, mix designs, equipment and curing materials that has developed in the last few years. 

The next panel we attended discussed Environmental Product Disclosures (EPDs), a labeling system that discloses the resource footprint of the many materials that go into the built environment. The panel also included the next iteration, the Health Product Disclosures, which discloses the materials and chemicals that have been proven or correlated in causing health problems for humans.
Central Concrete, a sponsor of the event, has been heavily involved in the EPD project for disclosing the materials for the concrete industry. Below is a photo of the panelists from this panel.

The last panel of the day went over Net Zero Energy buildings with John Andary and Scott Shell, pictured below. It was a fascinating look at what is currently possible with technologies now: buildings that use as much energy as they make. The building case studies discussed also illustrated how livable and workable these spaces were, with thought for passive heating and cooling. Many of the designs features windows that bounced daylight far into the building envelope, as well as fresh air ventilation. It was a wonderful talk, even though their topics stayed primarily inside the building envelope.

The final speaker, Jason McLennan, pictured below, gave a wonderful talk on self limits. His talk really stood out for his candor and optimism. For a young guy, has accomplished quite a bit in the green building spaces. Currently he is pioneering the Living Building movement.

After his talk, Jason McLennan was joined by George Salah, of Google, and David Gottfried of the USGBC. They discussed everything from George’s living-building home construction project to Jason’s motivation to do the work that he does: “I give a shit.” That was wonderful.

FInally, after it was all over, we found that there was a fantastic array of beers, wine and snacks to round out the day’s networking. It was a great event, and one we will look forward to attending next year!

A BIG thank you to Charlie Nucci, who took these photos at the event. You can find more about Charlie and his work at his website here.

NRMCA Technician Training in Truckee - A Success!

David teaches the NRMCA Pervious Concrete Technician class by the NRMCA local sponsoring group ACI Northern California chapter. The class location was in Truckee, CA and after the class and test, the class went out the TNT Materials Yard for a demonstration pour. We had good pervious pouring weather and great participation! If you would like more information for upcoming NRMCA pervious concrete training classes, go to the ACI website here: www.ACI-NCAWNV.org.

Check out the photos below:

Graniterock Quarry Tour - with Photos!

The Bay Area Pervious Concrete team went to visit Graniterock at their Aromas location. Lauren arranged for a tour with Graniterock with their testing group. We piled into a car wit Katha and Greg, both in the Graniterock materials testing group. First we went to visit Big Bill, the massive material spreader.

Big Bill (pictured above) was at the end of a 3mile conveyor belt bringing material from the waste end of the crushing processing to the spreader. The wheels were at least 10 feet in diameter! It was a massive machine! The material being spread looked like moon dust!

After leaving Big Bill we went into the quarry. You could see the step-like traces of material that had been removed. The terraces started at the top of the hill and went rather deep, below sea level! There was this massive truck (pictured above)that was moving the 'raw' rock and rubble close to the initial crushing machine (picture below). The crushing machine was in the quarry and it was even more massive then Big Bill the spreader! Here are a few photos of the team with the crusher. It was not running at the time, I would imagine it would be deafening! From the large initial crusher, another conveyor, shorter then the 3 miler, takes the material to the processing yard.

The material on the initial conveyor is then sorted into two sizes (big, for dry processing, and smaller, for wet processing) before being further sifted, crushed and rinsed to final product sizes and blends. The processing yard was a maize of conveyors, buildings on stilts (the crushing/processing/screening) and piles of material. Going into their control tower, we could see the levels of complexity and organization to keep all of that machinery moving that went unseen in the maize outside the windows. Even further beneath the surface of the processing yard was another conveyor in a tunnel beneath the main stockpiles, to allow for high control of the custom blends and product development.

Graniterock's newest addition to the quantitative analysis even had this fabulous quality assessment program that noted the size of final aggregate moment to moment to ensure consistency of the final product. They could, in real time, plumb their data and understand how consistent their product was, and make appropriate adjustments to bring it back into line. That type of feedback allows the quality team to be responsive to current inventory as well as give the operations team insights as to how well their processes are processing. It was a fantastic set-up, although I may be a data geek.

It was a fantastic tour of a great facility. We learned a lot about the aggregates that we use frequently in the Peninsula as well as how it gets to us. Really good quality rock makes even better pervious concrete! Please send us comments or questions! :)

Water Conservation Showcase a success!

Our own Lauren Wray attended the USGBC and P&E’s Water Conservation Showcase this year. The Bay Area Pervious Concrete Booth was in this video, above, and photos of Wray and pervious concrete made it into PG&E’s “Currents”, a P&E news site. Check out the video and let us know your thoughts! Did you attend the Water Conservation Showcase this year?

The Rational Method and Pervious Concrete

The Rational Method is used by many storm water civil engineers to understand storm water runoff. Frequently it is being invoked to understand the impacts of pervious concrete. Frankly, the Rational Method has no place designing with pervious, and this is what we are going to discuss.

The simplest reason being, the Rational Method is there the allow engineers to size the necessary sewer line appropriate to the runoff on the site. However, when pervious concrete is well designed and installed for most or all of the parking or access areas, there will be no runoff from that area. It is even possible, pending some limitations**, to capture most if not all of the adjacent runoff from impervious roofs or other impervious. That would make the runoff coefficient 0 or even negative. Given that, Q becomes zero, or less then zero. At that point, no drain pipe is needed to carry away the storm water, and the Rational Method is not the appropriate method for quantifying storm water.

This hints at the total shift that is before us - the way we previously understood hardscape and the associated negative externalities (runoff, storm water pollution, heat island effect, aquifer depletion) is turned on its head. Now these previous negative externalities are accounted for and reversed, and we are able to maintain the preferred hard & durable surface with pervious concrete. Pervious concrete allows storm water and pollution to filter in and infiltrate, allowing microbes and soil to be the filter that they are for the rest of nature. Pervious concrete mitigates the heat island effect in 2 ways, having a high solar reflectivity index as well as allowing a water and air exchange between the soil below and air above the pavement.

But given that codes are still being written, and some building and design professionals do not know about pervious concrete and its benefits we must still use the Rational Method. So I propose a stand-in coefficient.

To review the Rational Method for those of you who don't use this equation frequently,

Q = the necessary size of the pipe to capture the runoff being generated by C, I and A.

A = The area whose runoff is being measured.
I = The rate of rainfall in a given time horizon.
C = The coefficient that is determined by the type of ground covering being measured, below you can see one version of the chart referenced.

As you can see in the above chart, [impervious] paved surfaces gave a runoff coefficient of 0.94 for the 5-year storm event. Toward the bottom of this chart, "Lawn" and "Parks/Golf Courses/Cemeteries, 8% impervious" have a runoff coefficient of 0.21.

As far as I know, there is no such coefficient for pervious concrete to be used in the Rational Method. On the one hand, it isn't really necessary, as infiltration hardscapes may make the Rational Method less necessary. Or, perhaps the Rational Method will be adapted to vet and verify successful implementations of LID measures. In the meantime, it seems that a stand-in number is necessary - what if we were to use the "Parks/Golf Courses/Cemeteries, 8% impervious" 0.21 as a reference, and then include the >0.21, as it is less then 0.21, however it is unknown how much less at this point, for research has not yet been completed.

What do you think? Is this a reasonable way to discuss the Rational Method and pervious concrete?

** The limiting factor when dealing with pervious concrete is the subbase soil’s infiltration rate. Given enough area and enough reservoir base, it is possible to infiltrate a serious storm.

If you have more information please contact us, and we would be happy to discuss this with you.

----
Sources: chart http://www.iowadot.gov/design/dmanual/04a-05.pdf
conversation and cocktail napkin - inspiration to post

Pervious Patio at the Hyatt Regency SFO

The Hyatt wanted a new look and feel for two areas on either side of a walkway that connected the north entrance and the parking garage. They wanted to rip out the existing plants and replace it with a usable patio space. They also wanted pervious concrete - so they called us!

After we installed the Polished Pervious® concrete, we scored it, completing the look. The Hyatt put out this sleek and modern furniture, turning this previously unusable corner into a nice place to take a break! Below is the larger area, to the east of the pathway.

If you have a before and after job for us, let us know- contact us or leave a comment below!

Stormwater Sleuthing - Episode 1 - Woodside Runoff!

David Liguori went out into the field, during the last rain, to see what the stormwater runoff situation looked like in Woodside, California. Watch the video below to see what did and didn't run off!  

Come with David Liguori of Bay Area Pervious Concrete as he goes into the field, in the rain, to see first hand the issue of stormwater runoff - or lack there of - on pervious concrete versus other impervious hardscapes!

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 Video on PERVIOUS CONCRETE!

25 objects in just under 3 minutes -> How sharp are your eyes?

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.

Items to spy below. We recommend you increase the resolution to 720, otherwise, it is hard to see the details. How many did you catch the first time? How many times did it take for you to find them all? We recommend full screen to catch all the details!

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?

Pervious concrete and trees

How close can you pave to a tree?

Normally, it is inadvisable to pave inside the drip line of a tree. Depending on the size and age of a tree that can be a fairly sizable area. This can be problematic when traffic or use requires paving close to the tree. When traditional impervious pavements are installed near older established trees, it can spell the end of the tree. Is that true of pervious concrete?

It turns out there are two students at Texas A&M are doing this very research! Their recent work reveals pervious concrete does, in fact, enhance the growing conditions of established trees relative to traditional concrete. They poured traditional concrete around a few established trees, pervious concrete around a few established trees and left a few trees with no cover for the control, and measured tree health for a little over a year. The results: the trees surrounded by the pervious concrete had more trunk growth during the year then the trees surrounded by the traditional concrete!

What does this mean for you? The good news is that you can integrate pervious concrete paving into plant friendly parking lots and hardscape design, knowing that you are not compromising tree health. This also may open previously impossible parking or other paving possibilities due to the ability to extend the pervious concrete closer to the tree, well within the drip line. Yes, it can make installation tricky, but it can be done!

The takeaway is that pervious concrete is great for protecting mature trees. As you can see above, our clients think so too!

You can read more about pervious concrete effect on trees and their growth by reading the Texas A&M research paper listed on our Resources page.

2 Symptoms of Failed Pervious Concrete

2 Symptoms of Failed Pervious Concrete - Raveling and Sealing

Recently it has come to our attention that there appears to be a discrepancy in what a high-quality pervious concrete jobs looks like, and what has been passed off as high quality but in fact is not at all quality.

Failed installations have 2 main features: raveling and sealing.

Raveling is when the aggregate comes off of the slab as cement coated gravel. That can be an indication of poor mix design, poor installation technique or even misunderstand the weather's impact on the day of the pour.

Sealing is when the water pools and does not go through. It is possible to have sealing at the top, where it looks blotchy, or just beneath the surface such that the finish looks appropriate but does not drain. This is an indication of poor mix design. An experienced pervious concrete installer understands how critical the proper mix is and works closely with his ready-mix partners to get it right.

As we at BAPC have said before, pervious concrete is a tricky material and only those who are qualified, experienced and show a commitment to ongoing learning about techniques and mix designs are able to install and place pervious concrete with a consistent high quality.

We have created this video, complete with an amazing sound track, to illustrate what failed pervious concrete looks like, and what successful pervious concrete looks like. If you would like us to come out and evaluate your slab, or better yet, if you would like it done well the first time, please contact us.

The GREENEST mix - Pervious Concrete can get GREENER

The Greenest Mix we have ever devised!
Guest post, written by David Liguori

I wanted to give you a quick update on one of the more significant developments we’ve achieved lately.
 
In our continuing quest to further improve the performance of pervious concrete we have developed an “ultra-green” mix design for which we have recently received test data. The mix contains only 245 lbs. of cement, vs. 5-600 lbs. for regular concrete, and 245 lbs. of  supplementary cementitious materials (scm). The scm consists of a combination of fly ash and slag, both industrial waste products.
 
We used this mix this past January on a 2,000 ft. long (by 10’ wide) driveway in Palo Alto(photo above) and 3 months ago on a 5,000 sqft. driveway in Los Altos Hills (photo below). They are both performing quite impressively. Absolutely no surface raveling, all of which typically takes place in the first month or two if it’s going to happen, water infiltration rates of 700-1,200” per hour and compressive strengths above 3,000 psi.
 
As I am sure you know the addition of the scm’s slows down the rate of early strength gains but ultimately results in higher overall strength. In the case of the ultra-green mix our 28 day numbers are in the  2,600 – 2,900 psi range and to our delight the recent 90 day test came in at an outstanding 3,520psi. These type of results and data continue to increase our confidence in pervious concrete as viable long term stormwater management solution.

If you would like more details, contact us here and we will get in touch!

xx

This is the video from the longest (and greenest) pervious concrete driveway in the world!

This residential driveway is the world's longest pervious concrete driveway measuring half a mile long! It was designed and installed by Bay Area Pervious Concrete. If you would like to know more about pervious concrete and how it can absorb the puddles in your driveway, visit us at http://www.bayareaperviousconcrete.com.

Bunyan Pervious Roast 2012 - Hot days in the desert!

Bunyan Pervious Roast 2012 - Just outside Las Vegas

Out in the Nevada desert, outside of the Vegas we know is a far dustier affair known as the Pervious Roast. Dave Mitchell and team put together a spectacular 3+ days of speakers, pervious pours and food, which by all accounts was very informative and fun.

Our own David Liguori spoke at an un-scheduled moment to go over what goods and the not-so-good installations look and sound like. The video will be posted in an upcoming blog post. There were also presentations from Scott Erickson of Evolution Paving, and Jereme Montgomery.

BAPC's Rob Estrada was able to snag a picture with Matt Offenberg, of bell-ringing fame. You can see how glad they are to head into the (air conditioned) NRMCA meeting.

~ Update: Lauren Wray
- Photo Credits: Robert Estrada, David Liguori, Lauren Wray