Specialty Products Inc. s Synergy Series Ultra Bond III Polyurea and the LPG TM Proportioner: Revolutionizing Concrete Rehabilitation

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1 Specialty Products Inc. s Synergy Series Ultra Bond III Polyurea and the LPG TM Proportioner: Revolutionizing Concrete Rehabilitation Rehabbing 25 manholes for the City of Montrose, Colorado could have been a real nightmare, but with SPI s Ultra Bond III polyurea coating and portable LPG TM proportioner, the job went smoothly, says Eddie Kelley of Airtight Foam Solutions. In fact, it was pretty much flawless. This is high praise indeed because as anyone in the industry knows, manhole rehabilitation is one of the most challenging jobs out there. Tight spaces, limited access, advanced concrete degradation, and in most cases, an unforgiving schedule are just a few of the challenges that coating contractors face when embarking on a manhole rehab project. However, as Kelley testifies, it IS possible to have a relatively painless job when using SPI s Synergy Series LPG proportioner and Ultra Bond III polyurea. Together, these two innovative technologies are invaluable when relining concrete manholes. Merciless Conditions The waste water treatment process produces significant sulfur reducing bacteria (SRB) growth and hydrogen sulfide gas (H2S). These two factors can cause significant concrete damage as they break down the concrete s silica and calcium. Over time, exposure to these harsh conditions break down the concrete to such a degree that one of two things must be done the manhole must be replaced or relined. Manhole replacement involves digging up the existing manhole and completely replacing all its components. This process is both expensive and labor intensive, therefore, not a viable option for most wastewater districts. Recoating the manhole is the option chosen by the majority of municipalities. The right protective coating will shield the concrete from decay caused by the bacteria, extending the service life of the manhole structure. The proper coating system will also have enough elongation to handle thermal concrete expansion and contraction from annual freeze/thaw cycles. Eliminating Steps and Saving Money

2 Although the recoating option is not as cost prohibitive or labor intensive as the replacement of a manhole structure, it is still a daunting task. That is until the invention of SPI s Synergy Series chemistries and the LPG TM proportioner. These two technologies address the many challenges of manhole rehabilitation, making the process much more manageable, and ultimately, saving time and money for wastewater districts. Using the LPG TM proportioner, Ultra Bond III can be applied directly onto the porous concrete substrate, says Chas Weatherford, of SPI. There is minimal prep work other than removal of damaged concrete by pressure washing and abrasive blasting. No primer is required. Up until the advent of the Synergy Series chemistries and the LPG TM proportioner, coating concrete was a tough challenge for the polyurea industry. Polyurea applied through traditional high pressure, high heat, plural component equipment typically experiences blow holes. These blow holes are caused by air that is trapped within the pores (bug holes) and capillaries of the concrete. The air expands from the heated product as it is applied; pressure builds and pushes the trapped warm air through the surface of the freshly applied coating, potentially creating hundreds of pinholes per square foot. Preventing and/or repairing pinholes is extremely labor intensive. In an attempt to avoid pinholes, the concrete needs to be base coated using another material such as a plasticized mortar or urethane foam in order to fill surface irregularities and act as a buffer layer between the concrete and polyurea. If any pinholes occur once the polyurea is applied, caulk must be used to fill each pinhole and the coating must be resprayed over the affected areas. These blow holes are like mini-moon craters, says Dan Helton, President of SPI. There can be hundreds per square foot and they take a lot of time and money to repair. It is not feasible to coat a manhole with polyurea without the Synergy Series chemistry and the LPG TM proportioner. This entire labor intensive and cost prohibitive nightmare is averted by the Synergy Series chemistries and the LPG TM proportioner technologies. The Ultra Bond III TM polyurea is applied at a low temperature, approximately 90 Fahrenheit. This low temperature virtually eliminates moon craters caused by the blow holes. In addition, the product is air-nucleated. This adds body to the coating which bridges the capillaries and surface irregularities. The end result is a smooth, monolithic surface that is free of defects, says Helton. Weatherford concurs. Applying Ultra Bond TM III with the LPG TM machine creates a monolithic polyurea liner that is free of blow holes or pinholes. Another important advantage with using the Synergy Series LPG equipment and chemistries is this technology eliminates the need to use polyurethane spray foam as a base coat over the manhole concrete surface. Spray foam is often used as a base coat to help prevent issues with bug holes and pinholes. This added step and increase in product/labor cost can now be avoided. A Tight Squeeze

3 The LPG TM proportioner also has another important advantage. Unlike traditional plural component proportioners, it is lightweight and portable. By definition, manholes are confined spaces and many of them are in areas with limited access. SPI s Synergy Series LPG TM weighs less than 80 lbs. and can be transported in the back of a pick-up truck. This portability allows applicators to place the machine near the actual spray site, even if it s hard to access. In addition, the LPG TM only requires a standard wall outlet (110 V) for power, making it even more convenient for hard to reach spray sites. LPG TM and Synergy Chemistry in Action The best way to demonstrate just how well Ultra Bond TM III and the LPG TM work together out in the field is to revisit the City of Montrose manhole rehabilitation project. The City of Montrose, Colorado Public Works Utilities Division had 25 manholes that needed a new protective lining due to concrete degradation. The manholes have been in service for approximately 25 years. According to Weatherford, the city decided that recoating the manholes was more cost advantageous than the replacement of the sewer infrastructure. This is where Kelley of Airtight Foam Solutions comes into play. We got the contract and were initially going to spray polyurethane foam over the concrete and then coat with polyurea. After running into several pre-job issues, we talked with SPI and they suggested using the Ultra Bond TM III material, without the use of spray foam, and applying it with the LPG TM proportioner, says Kelley. We were happy to use this innovative technology, especially since it saved so much time and money. According to Kelley, many of the manholes were in pretty bad shape. The concrete was badly deteriorated due to the hydrogen sulfide gas and high moisture content. In addition, some of the manholes had an epoxy coating that had been applied a few years before. The epoxy coating did not hold up well under the harsh conditions present in the manhole structure or the annual weather cycle. Kelley states that in some manholes, he and his crew had to use a hand trowel to remove 1 to 1 ½ inches of damaged concrete prior to pressure washing and abrasive blasting the manhole structure. The application of Ultra Bond TM III would significantly extend the service life of the manholes, as it is specifically designed to endure exposure to severe chemical and weather conditions. Live Sewer, Big Challenge To add to the challenges of this particular job, the sewer main was to remain live during the entire process yet another reason why an expedited coatings process was essential. Gas monitors were used at all times during all prep and spray work to ensure the safety of Kelley and his crew. In addition, the

4 crew wore all of the proper safety gear, including Tyvek suits, rubber gloves, a fresh air hood and OSHA compliant harnesses. Also, since the sewer lines were running, Kelley had to engineer a system to keep the debris and overspray from falling into the line. We built wood benches around the invert. It was a tri-fold contraption that was lowered into the manhole structure with a tri-pod and winch and then unfolded. A canvas tarp was on top of the wood, allowing us to catch all the debris, says Kelley. Once the containment apparatus was in place, the crew removed all damaged concrete and then pressure washed and abrasive blasted the manhole. Thanks to the Synergy Series chemistry and the LPG TM, the manhole was ready for the polyurea application without the need for primers, mortars or foam. Ready Aim Spray Prior to the application of the Ultra Bond TM III, Kelley and his crew used a 400,000 BTU ducted heater to pump heat into the manhole. This dry, hot air took the moisture out of the manhole structure and raised the temperature to about 90 degrees Fahrenheit inside the manhole, says Kelley. The heat duct was removed from the manhole and the crew then applied an average of 120 mils of Synergy Series - Ultra Bond III polyurea to the concrete substrate. According to Weatherford, the Airtight Foam Solutions applicator was able to adjust the product output using controls at the Lock-n- Load gun. This enabled him to adjust the spray pattern diameter and output as needed to properly coat different surface areas within the manhole structure. Once the polyurea application was completed, the heating duct was once again used to pump heat into the manhole. The duct remained there for one hour in order to expedite the front-end curing of the product. The return to service was immediate; the sewer was live the entire time and there was no disruption of the wastewater system. Kelley is quick to point out that the portability of the LPG TM proportioner was a huge part of the success of the City of Montrose job. Nearly half of the manholes were difficult to access. There was no way that I could have gotten my 36-foot goose neck trailer anywhere close to some of them. We were able to put the LPG TM into a smaller truck and had no problems getting to any of the manhole locations, says Kelley. With the Ultra Bond TM III and LPG TM Synergy Series technology, Kelley and his crew were able to prep and spray all 25 manholes in 14 days, an impressive feat to say the least. The application equipment was simple to use and not having to apply another material prior to the polyurea saved an unbelievable amount of time and money, says Kelley. The Solution for Failing Infrastructure

5 SPI has been manufacturing polyurea protective coatings and using traditional equipment within the wastewater industry since Years of accumulated knowledge helped SPI to identify the need for a coatings technology breakthrough, namely the teaming of Synergy Series chemistries and the LPG TM proportioner. With these two innovative technologies, SPI provided a protective coating solution to extend the service life of the existing manholes and save the City of Montrose and its tax payers a substantial amount of money. As the wastewater infrastructure in the U.S. continues to age, more and more municipalities will face the same dilemma as the City of Montrose manhole replacement or rehabilitation. SPI s Synergy Series chemistries and the LPG TM offer the best and most cost-effective solution for the rehabilitation of the wastewater infrastructure. For more information regarding SPI s Synergy Series chemistries and the LPG TM proportioner, please contact Specialty Products Inc. at (800) or info@specialty-products.com.