Award Bid - 2024 Sewer and Manhole Rehabilitation Proj No. 122-019 - Visu-Sewer, LLC

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CURED-IN-PLACE PIPE SAMPLING PROCEDURES The following is a summary of recommended cured-in-place pipe (CIPP) sampling procedures. There are two accepted methods of obtaining samples from installed CIPP: 1) a plate molded sample of resin and felt from the installed tube, and 2) a restrained piece of CIPP cut from the liner itself. In addition to proper sampling, it is critical to obtain the required size of sample to perform the flexural property testing that is typically performed to evaluate the minimum physical requirements. For either type of sampling procedure, the required sample sizes should be in the following range in order to have enough material to evaluate: • For 4.5-13.5 mm thick CIPP, the sample should be 6 in. wide and 10 in. long. • For 15-21 mm thick CIPP, the sample should be 8 in. wide by 15 in. long. • For 22.5-28.5 mm thick CIPP, the sample should be 10 in. wide by 24 in. long. PLATE MOLDED SAMPLES The most consistent and highest quality sampling technique is to produce plate molded samples that are placed in the column during the cure process. In general, it becomes extremely difficult to obtain restrained samples from CIPP larger that 18 inch diameter due to the restriction of size of the manhole ring itself. Therefore, plate molded sampling is perhaps the only reliable method for sizes greater than 18 inch diameter. However, this sampling technique can be used for any size or thickness of CIPP. The plates should be 3/16 or 1/4 inch thick aluminum, which is probably the best material because it is light and resists oxidation. Care should be taken in handling the sample plates so that the plates are not scratched on the surface where the wet out liner is to be positioned. Plates fabricated to a size to accommodate the aforementioned dimension ranges. Spacer bars must also be prepared to provide the required thicknesses of the tubes installed. The actual process of preparing plate-molded samples is best accomplished in the following manner: • Select the appropriate size plate for the sample being prepared and coat the inner surface of the plate with a liberal amount of mold release (i.e., PVA). • Prepare a Polyurethane or plastic sleeve that it is the appropriate size for your plate. • Seal three sides of the sleeve. • Prepare two Mylar sheets and place inside the sleeve. • From a piece of well saturated liner that is to be installed, cut out the appropriate size of material based on the thickness of tube installed. For best results, only use saturated felt without any plastic coatings. • Place saturated felt layer(s) into a plastic or polyurethane sleeve, between the two Mylar sheets, and squeeze out all excess air. For best results place the saturated felt at one edge of the sleeve with all the excess on the other side.