We are a shotcrete company in Southern California, and I have a technical question about an issue that has recently come up. Is there any official ASA or ACI guide/spec that recommends or lays out the use of a certified nozzleman on a job that he was not “job site” approved for? For instance, a nozzleman who did not shoot a test panel was overseen by the approved nozzleman for that job site. I understand that the approved nozzleman can oversee another ACI-certified nozzleman on the job so that he can rest and oversee production. Seeing as the approved man is overseeing the nozzleman, is it the same as him shooting the wall himself?
It appears you are talking about a nozzleman who has not been pre-qualified by shooting a mockup panel on a specific project. There is no official ASA or ACI document that addresses this issue. However, this situation is similar to what ACI guidance provides regarding ACI-certified Shotcrete Nozzlemen and Nozzlemen-in-training. ACI’s Certification Program Policy for Shotcrete Nozzleman and Nozzleman-In-Training Section 1.04 states: “ACI Shotcrete Nozzleman-In-Training (NIT) certification is available to applicants who do not possess 500 hours of work experience but do possess a minimum of 25 hours of hand nozzling work experience in the process being sought (vertical orientation only). The examiner of record may require an ACI-certified nozzleman to be present during the performance exam; however, the ACI-certified nozzleman’s interaction with the examinee is strictly limited to the safety of the shooting operation.”
We are having a pool installed and would like to know if shotcrete should be placed when severe weather is forecasted for late in the day or the next day? Is it possible to cover the area after application to protect it?
Shotcrete is a method for placing concrete. Concrete has a set time that provides hardness of the in-place concrete. Final set may take anywhere from an hour to several hours depending on the concrete mixture and the weather.
Hot weather has a faster set time than cold weather with the same concrete mixture. If the pool is shot in the morning, it may be hard enough to tolerate a rainstorm in the late afternoon. The concrete should certainly be set by the next day unless there is a very cold overnight temperature or a problem with retarder in the concrete mixture. Tarps could be placed over the vertical walls to protect them from a sudden rainstorm. The floor may be harder to protect as the rainwater wouldn’t necessarily drain off the floor.
If concrete is exposed to rain and the surface isn’t washed off in any way, the concrete should be good. Similarly, if you are expecting freezing temperatures overnight, the fresh concrete must be protected from freezing. This may require using vented heaters and insulated blankets. The goal of the cold weather protection is to keep the surface temperature of the fresh concrete above 50°F (10°C). More details on cold weather protection can be found in ACI PRC-306-16 Guide to Cold Weather Concreting available directly from ACI’s bookstore (concrete.org/store.aspx).
Please direct me to the proper guidelines for the hydration of shotcrete.
By hydration, I’m assuming you are referring to curing of freshly placed concrete. A minimum of 7 days of continuous wet curing is recommended. Continuous means the exposed concrete surface is wet the entire duration. Not just “watered” twice a day as has sometimes been suggested by contractors. Use of a spray-on curing membrane is an option if for some reason water curing is not practical.
If you are looking specifically at swimming pools, this ASA Pool and Recreational Shotcrete Committee Position Statement “Curing of Shotcrete for Swimming Pools” provides more details: shotcrete.org/wp-content/uploads/2022/01/218216_ SCMSummer21_PS7v2.pdf Also, for a more detailed look at curing, the American Concrete Institute (ACI) document, ACI PRC-308-16 Guide to External Curing of Concrete is an excellent reference.
You can find this at ACI’s bookstore (concrete.org/store.aspx). Finally, a good reference on the basics of concrete, from materials to placement and curing, is the Portland Cement Association’s “Design and Control of Concrete Mixtures, 17th Edition.” You can find this on the PCA website bookstore.
Honorable Mention Project
Time | Event | Location |
|---|---|---|
8:00AM – 4:00 PM | Contractor Education Seminar | Rio Grande II |
8:00AM – 4:00 PM | Quality Shotcrete Seminar – Recognizing it when you see it (Pool) | Rio Grande I |
10:00AM – 3:00 PM | Offsite Activity – Clay Shooting | Reunion Ranch | Hacienda Ballroom |
4:00PM – 6:00 PM | Exams – Contractor Education | Rio Grande I |
4:00PM – 6:00 PM | Exams – Pool Certificate | Rio Grande I |
5:00PM – 9:00 PM | ASA Registration | Rio Vista Ballroom |
7:00PM – 9:00 PM | Savor the Taste: Exploring Austin’s Distilled Delights & Exhibitor Showcase | Vista Ballroom |
Time | Event | Location |
|---|---|---|
7:00 AM – 6:00 PM | ASA Registration | Vista Ballroom |
7:00 AM – 8:00 AM | Breakfast & Exhibitor Showcase | Vista Ballroom |
7:00 AM – 4:00 PM | Exhibitor Showcase | Vista Ballroom |
8:00 AM – 9:00 AM | How Shotcrete Helped Transform UMD’s Cole Field House From Basketball Venue | Trinity Room |
8:00 AM – 9:00 AM | Shotcrete Challenges on High End Swimming Pool Projects | Rio Grande I |
8:00 AM – 9:00 AM | Tunneling Under Lake Travis
| Rio Grande II |
10:00 AM – 10:30 AM | Break & Exhibitor Showcase | Hacienda Ballroom |
9:00 AM – 10:00 AM | Shotcrete Mix Design 101
| Trinity Room |
9:00 AM – 10:00 AM | Understanding Alkali Silica Reactions | Rio Grande I |
9:00 AM – 10:00 AM | Silicate-Based and Alkali-Free Accelerators for Shotcrete Applications | Rio Grande II |
10:00 AM – 10:30 AM | Break & Exhibitor Showcase | Vista Ballroom |
10:30 AM – 11:30 AM | Shotcrete Placement – Report on Recent Research from Rheology to Robotics | Trinity Room |
10:30 AM – 11:30 AM | How Not to Shotcrete a Pool | Rio Grande I |
10:30 AM – 11:30 AM | Practicing Cold Weather Shotcreting in Canada and Northern USA | Rio Grande II |
11:30 AM – 1:30 PM | Lunch and Exhibitor Showcase | Vista Ballroom |
12:30 PM – 1:30 PM | Membership Committee | Rio Grande II |
1:30 PM – 2:30 PM | Marketing Committee | Rio Grande II |
2:30 PM – 3:00 PM | Break & Exhibitor Showcase | Vista Ballroom |
3:00 PM – 4:00 PM | Underground Committee | Rio Grande II |
4:00 PM – 5:30 PM | Pool and Recreational Shotcrete & Contractor Qualification | Rio Grande II |
6:00 PM – 8:30 PM | ASA Reception & Dinner | Vista Ballroom |
Time | Event | Location |
|---|---|---|
7:00 AM – 5:00 PM | ASA Registration | Vista Ballroom |
7:00 AM – 8:00 AM | Breakfast & Exhibitor Showcase | Vista Ballroom |
7:00 AM – 4:00 PM | Exhibitor Showcase | Vista Ballroom |
8:00 AM – 9:00 AM | Education & Safety Committee | Rio Grande II |
9:00 AM – 11:30 AM | Board of Directors Meeting | Rio Grande II |
10:00 AM – 10:30 AM | Break & Exhibitor Showcase | Vista Ballroom |
11:30 AM – 1:30 PM | Lunch & Exhibitor Showcase | Vista Ballroom |
12:30 PM – 1:30 PM | Estimating Shotcrete Strength by the Maturity Method | Trinity Room |
12:30 PM – 1:30 PM | Common Practices in Swimming Pool Shotcrete | Rio Grande I |
12:30 PM – 1:30 PM | VAE copolymer binders for modern concrete tunneling construction | Rio Grande II |
1:30 PM – 2:30 PM | Development of Ultra Rapid Setting High Performance Dry-Mix Shotcrete | Trinity Room |
1:30 PM – 2:30 PM | Improving Swimming Pool Vessels with Great Communication | Rio Grande I |
1:30 PM – 2:30 PM | Encore #1 | Rio Grande II |
2:30 PM – 3:00 PM | Break & Exhibitor Showcase | Vista Ballroom |
3:00 PM – 4:00 PM | Use of Liquid Admixtures in Dry Process Shotcrete | Rio Grande I |
3:00 PM – 4:00 PM | Lowering the Carbon Footprint of Conventionally Excavated Tunnel Linings | Rio Grande II |
3:00 PM – 4:00 PM | Encore #2 | Trinity Room |
6:00 PM – 10:00 PM | Outstanding Shotcrete Projects Award Ceremony and Banquet | Vista Ballroom |
ASA Conventions provide a unique opportunity to network with leaders in the industry and hear the latest advances in shotcrete technology! This year we will have three tracks, including tracks for Pools and Underground presentations respectively.
3 Reasons to Sponsor:
- Support the work of the Association as we seek to expand and advance global utilization of the shotcrete process for concrete placement.
- Promote your company as a stakeholder in Quality Shotcrete applications.
- Opportunity to EXHIBIT your company at the Convention as one of our tabletop exhibitors, co-located with included meals and breaks at the Convention
Sponsorship Options
Sponsorship – Big Shooter
$5,000 (No Shipping)
Sponsorship – Gold
$2,500 (No Shipping)
Sponsorship – Silver
$1,000 (No Shipping)
Email your logo & preferred web link to [email protected]; Include in the subject line: 2025 Sponsor
*Those who wish to exhibit must register attendee separately (to staff your exhibit table) here: www.shotcrete.org/convention