Reference US 02/95 Wet Spray Application SewperCoat® PG

The reference

Prior to repair, the sewerage flow was bypassed, the chamber was pressure washed, debris removed, gas levels checked and ventilation provided. SewperCoat, manufactured by Lafarge Calcium Aluminates, was applied using low-pressure, wet-spray equipment.

The material was mixed at a ratio of approximately 1 gallon of water per 65# bag. This mixture utilized the hydraulics of the machine to pump the SewperCoat through a progressive cavity type pump.

One coat of SewperCoat was applied to the ceiling and two coats were applied to the walls. The next day, two additional coats were applied to the ceiling. The chamber was returned to service the following morning.

The repair was completed in approximately eight hours with a minimum one inch of material applied overal and with as much as three to four inches in some areas. A total of 150 bags of Sewpercoat were used to complete the job.

Description1

®SewperCoat PG

Reference SheetReference US 02/95

Wet Spray Application

Severe deterioration up to4 inches in some places

SewperCoat is applied using thelow pressure, wet spray method

&The City of Ormond Beach Treatment Plant scheduled their primary collection chamber for rehabilitation in December 1994 due to severe deterioration resulting from high concentrations of H S (hydrogen sulfide) gas.2

&The chamber, approximately twelve feet in length, nine feet in width, and sixteen feet deep, had been in service for less than five years.

&The loss in wall thickness, ranging from one to four inches, was so severe that the reinforcing steel was exposed.

& Installer: City of Ormond Beach, Florida

&Method of Placement: "Low-pressure, wet-spray" method

LAFARGE CALCIUM ALUMINATES, INC.1316 Priority Lane, Chesapeake, VA 23324Phone: (757) 543-8832 Fax: (757) 543-1002

SewperCoat was tested and measured 3.0 pH after 6 months in the collection chamber.

The surface was struck with a manhole cover pick to confirm the visual inspection.

SewperCoat has no signs of degradation after six months of operation. Very good surface appearance.

A six month evaluation was conducted on the primary collection chamber at the City of Ormond Beach and the SewperCoat was found to be in excellent condition; aptly resisting the highly corrosive environment.

Prior to inspection, a gas meter was lowered into the chamber and the reading registered greater than 100 ppm of H S gas. The pH reading was checked with 2

both litmus type paper and a pH pencil. The results were measured and recorded as shown below.

The surface was checked for any cracking or signs of deterioration. The surface was struck with a manhole cover pick confirming the visual inspection.

The SewperCoat is rock solid after six months in this structure. This structure previously experienced three to four inches of biogenic degradation after only two years in service.

Six Month Evaluation2

A one year evaluation was conducted on the primary collection chamber at the City of Ormond Beach and, as in the earlier evaluation, the SewperCoat was found to be in excellent condition; continuing to resist the highly corrosive environment. The surface pH was checked and SewperCoat continues to control the surface pH and keep it at 3.0..

The surface was checked for any cracking or signs of deterioration both visually and with a manhole cover pick to confirm the visual inspection.

After one year, the SewperCoat is rock solid, when prior to rehabilitation this structure experienced three to four inches of biogenic degradation after only two years in service.

One Year Evaluation3

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The bottom of the existing cover is indicative of high biogenic corrosion on the chamber.

The pH measured above the effluent level on SewperCoat is approximately 3.0.

After one year of operation, SewperCoat is rock solid with no sign of degradation.


Eighteen Month Evaluation4

An eighteen month inspection was conducted on June 20, 1996. As expected, the SewperCoat continues to perform with no signs of deterioration.

In addition to a visual inspection, pH measurements were obtained with consistent results of 3.0. These results continue to confirm laboratory predictions.

After 18 months, SewperCoat is rock solid with no sign of degradation. The surface was struck with a manhole pick to confirm the visual inspection.

The substrate pH level after 18 months of service measured 3.0.

Two Year Evaluation5

A two year inspection of the primary collection chamber was conducted on January 23, 1997.

The chamber was evaluated for material loss, pH, and surface/lining quality. The SewperCoat continues to perform well, as expected.

The surface continues to produce a pH measurement greater than 3. Trowel marks from the original installation are still visible. During the evaluation, Ormond Beach personnel, Steve Bechtel said, “It’s hard to believe, but it’s as hard as the day we put it in.”

The surface was struck with a manhole pick to demonstrate its solid properties.

The surface pH continues to measure greater than 3.

Trowel marks are still evident after two years of service.

The external attack on the discharge line, installed after the 12 month evaluation, clearly demonstrates the corrosive nature of this environment.

Three Year Evaluation6

The three year inspection, conducted in January 1998, revealed positive and expected results. SewperCoat continues to perform as predicted given the severely corrosive environment. This has lead the City of Ormond Beach to specify SewperCoat for other corrosive areas.

Surface pH of 3, visible trowel marks and surface hardness continue to verify SewperCoat's performance. The pure calcium aluminate mortar has demonstrated its value and will continue to provide long-term protection against biogenic corrosion.


Five Year Evaluation7

The 5 year evaluation yielded results similar to those of the 3 year evaluation. The pH value measured on the surface of the SewperCoat was > 3.0. The accessible SewperCoat surface was sounded with a pick, exhibiting rock hard properties with no signs of delamination. Trowel marks from the installation process are still visible after 5 years in service.

SewperCoat’s unique properties continue to protect this structure, maintaining a surface pH greater than 3.0. Ormond Beach continues to be extremely confident in SewperCoat as a lining material for structures throughout their wastewater network.

The amount of turbidity is also a factor governing the extreme generation of hydrogen sulfide (H S).2

Another indication of the excellent performance is the absence of any surface degradation.

The pronounced trowel marks on the SewperCoat surface are an indication of its excellent performance. The corroded ductile iron pipe continues to demonstrate how aggressive this environment is.

The installed SewperCoat is still rock hard and performing as predicted. The measured pH value was still >3.0.

Seven and ½ Year Evaluation8

The 7-½ year inspection, conducted in March 2002, yielded some surprising results. The H S measurement 2

was extremely high at > 100 ppm. The surface pH was measured at 5.0. There are still trowel marks visible in areas of this structure. The SewperCoat surface was also subjected to a thorough high-pressure (5,000 psi) cleaning during this visit. This 5,000-psi water blasting was held just inches from the surface removing only slime and debris, not SewperCoat. This long term performance has proven the value and performance of SewperCoat in the most extreme wastewater environment in the United States, namely Florida.

SewperCoat subjected to a 5,000-psi water blasting just inches from the surface exhibits no loss of thickness or latence.


Documents

Reference US 02/95 Wet Spray Application SewperCoat® PG