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same geomembrane extending a minimum of six (61 inches beyond the <br />cut in all directions. <br />d. Extend seaming to the outside edge of panels placed in the anchor <br />trench. <br />e. Do not field seam without the Seaming Supervisor present. <br />D. Field Trial Seams <br />1. Trial seams shall he conducted at the beginning of each seaming period and <br />within thirty (301 minutes of commencement of seaming, at the MANAGER'S <br />and CERTIFYING ENGINEER'S discretion, and immediately fallowing any work <br />stoppage (i.e., lunch, weather conditions, etc.l of thirty (301 minutes or more <br />for each seaming apparatus used that day. Each Seamer shall make at least <br />one trial seam each day. <br />2. Testing shall include visual observation of a trial seam on the geomembrane <br />material. The INSTALLER will mark the trial seam with date, ambient air <br />temperature, welding machine number, welding technician identification, and <br />machine temperature and speed. For extrusion welding, the INSTALLER will <br />include the nozzle and extrusion settings and welding technician identification. <br />The remainder of trial seam should be cut in two pieces; one to be retained in <br />the OWNER'S archive; and one to be retained by the INSTALLER. <br />3. All trial seams shall `~e made at a location selected by the MANAGER and <br />CERTIFYING ENGINEER in the area of the seaming and in contact with the <br />subgrade. The trial seam samples shall be ten (70) feet long for fusion seaming <br />and five 161 feet long for extrusion seaming, with the seam centered <br />lengthwise. Specimens one 111 inch wide shall be cut from opposite ends of <br />the test seam by CONTRACTOR. CONTRACTOR shall use a tensiometer to test <br />these specimens for shear and peel. Both inside and outside tracks of fusion <br />welds will be tested far peel. For both fusion and extrusion welds, two (21 <br />coupons will be tested for peel and one (11 coupon for shear. The tensiometer <br />shall have a grip separation of four (4! inches plus the width at the seam. The <br />seam is to be centered between the Gamps. The grip separation rates for <br />LLDPE are twanry (201 inches per minute far shear and twenty (201 inches per <br />minute for peel. The grip separation rates far HDPE are two (21 inches per <br />minute far shear and two (2) inches per minute for peel. These tests shall not <br />fail according to the criteria in Section 2.01. A break through the weld ar at <br />the weld/sheet interface shall be considered a failure in both shear and peel <br />strength rasa unless the weld strength exceeds the sheet strength, as <br />discussed in Section 2.01. If a trial seam fails to meet field seam <br />SPECIFlCATIONS, the seaming apparatus and/ar seamer shall not be accepted <br />and shall not be used for seaming until the deficiencies are corrected and two <br />consecutive successful full trial seams Ara achieved. <br />4. CONTRACTOR shall mark the test weld with date, ambient temperature, <br />welding machine number, welding technician identification, machine <br />temperature and speed. For extrusion welding, CONTRACTOR shall record the <br />nozzle and extrusion settings. <br />5. CONTRACTOR shall cut remainder of successful vial seams into two pieces, <br />March 26, 1996 Section 02776.0 <br />02778.0-18 Geomembrane <br />Revision 4 <br />