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Section 02776 <br />Geomembrane <br />D. Field Trial Seams <br />amee <br />1. Trial seams shall be conducted at the beginning of each seaming period and within 1 <br />hour of commencement of seaming, at the CERTIFYING ENGINEER's discretion, and <br />immediately following any work stoppage (i.e., lunch, weather conditions, etc.) of 1 hour <br />or more for each seaming apparatus used that day. Each Seamer shall make at least one <br />trial seam each day. <br />2. Testing shall include visual observation of a trial seam on the geomembrane material. <br />The INSTALLER will mark the trial seam with date, ambient air temperature, welding <br />machine number, welding technician identification, and machine temperature and speed. <br />For extrusion welding, the INSTALLER will include the nozzle and extrusion settings <br />and welding technician identification. <br />3. All trial seams shall be made at a location selected by the CERTIFYING ENGINEER <br />in the area of the seaming and in contact with the subgrade. The trial seam samples shall <br />be ten (10) feet long for fusion seaming and five (5) feet long for extrusion seaming, with <br />the seam centered lengthwise. Specimens one (1) inch wide shall be cut from opposite <br />ends of the test seam by CONTRACTOR. CONTRACTOR shall use a tensiometer to <br />test these specimens for shear and peel. Both inside and outside tracks of fusion welds <br />will be tested for peel. For both fusion and extrusion welds, two (2) coupons will be <br />tested for peel and one (1) coupon for shear. The tensiometer shall have a grip separation <br />of four (4) inches plus the width of the seam. The seam is to be centered between the <br />clamps. The grip separation rates for LLDPE are twenty (20) inches per minute for shear <br />and twenty (20) inches per minute for peel. These tests shall not fail according to the <br />criteria in Section 2.01. A break through the weld or at the weld/sheet interface shall be <br />considered a failure in both shear and peel strength tests unless the weld strength exceeds <br />the sheet strength, as discussed in Section 2.01. If a trial seam fails to meet field seam <br />SPECIFICATIONS, the seaming apparatus and/or seamer shall not be accepted and shall <br />not be used for seaming until the deficiencies are corrected and two consecutive <br />successful full trial seams are achieved. <br />4. CONTRACTOR shall mark the test weld with date, ambient temperature, welding <br />machine number, welding technician identification, machine temperature, and speed. For <br />extrusion welding, CONTRACTOR shall record the nozzle and extrusion settings. <br />3.08 NONDESTRUCTIVE TESTING <br />A. CONTRACTOR shall non - destructively test all field seams over their full length. All test <br />equipment shall be furnished by CONTRACTOR. <br />B. The following vacuum box procedures are applicable to extrusion seaming and shall be followed <br />by CONTRACTOR: <br />1. Excess sheet overlap shall be trimmed away. <br />2. Clean the vacuum box window, gasket surfaces and check for leaks. <br />3. Energize the vacuum pump and reduce the tank pressure to approximately 5 psi. <br />4. Wet a strip of geomembrane the approximate dimensions of the vacuum box with the <br />soapy solution. <br />Page 17 of 22 <br />June 19, 2012 <br />Revision 1 <br />