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ameO <br /> D. Field Trial Seams <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 /> Section 02776 Page 17 of 22 May 9,2012 <br /> Geomembrane Revision 1 <br />