Basis of Payment 610.24 The quantity, determined as provided above, will be paid for at the contract price per unit of measurement, respectively, for each of the particular pay items listed below that is shown in the bid schedule, which price and payment will be full compensation for all work included in this section except furnishing and placing steel S-bar anchors, which will be measured and paid for under Section 554. No direct payment will be made for metal slots, anchors, or other devices placed in accordance with subsection 610.17(b). Payment will be made under: 613.01 This work shall consist of Reinforced Earth* walls constructed in accordance with these specifications and in reasonably close conformity with the lines, grades, design, and dimensions shown on the plans or established by the Engineer. *a trademark. Materials 613.02 General. The Contractor shall make his own arrangements to purchase the face panels, reinforcing and tie strips, fasteners, joint filler, and all necessary attachments from sources listed in the contract documents. (a) Concrete Face Panels. Cement shall be Type II conforming to Section 701. Concrete shall have a minimum compressive strength at 28 days of 4500 psi (31.03 MPa). Air entraining, retarding or accelerating agents or any additive containing chloride shall not be used without approval of the Engineer. Tie strips connecting pins, and PVC pin form and lifting and handling devices shall be set in place to the dimensions and tolerances shown on the plans prior to casting. (1) Testing and Inspection. Acceptability of the precast units will be determined on the basis of compression tests and visual inspection. The precast units shall be considered acceptable regardless of curing age when compression test results indicate strength will conform to 28-day specifications. The Contractor or his supplier shall furnish facilities and perform all necessary sampling and testing in an expeditious and satisfactory manner. Panels shall be considered acceptable for placement in the wall when 7-day strengths exceed 60 percent of 28-day requirements. (2) Casting. The panels shall be cast on a flat area, the front face of the form at the bottom, the back face at the upper part. Tie strip guides shall be set on the rear face. The concrete in each unit shall be placed without interruption and shall be consolidated by the use of an approved vibrator, supplemented by such hand-tamping as may be necessary to force the concrete into the corners of the forms and prevent the formation of stone pocket or cleavage planes. Clear form oil of the same manufacture shall be used throughout the casting operation. (3) Curing. The units shall be cured for a sufficient length of time so that the concrete will develop the specified compressive strength. Any panel pour which does not reach specified strength within 28 days shall be rejected. (4) Removal of Forms. The forms shall remain in place until they can be removed without damage to the unit. (5) Concrete Finish and Tolerances. Concrete surface for the front face shall have the finish approved by the Engineer and for the rear face an unformed surface finish. Rear face of the panel shall be roughly screeded to eliminate open pockets of aggregate and surface distortions in excess of 4-inch (6.35 mm). (6) Tolerances. All units shall be manufactured within the following tolerances: All dimensions within 6-inch (4.76 mm). Angular distortion with regard to the height of the panel shall not exceed 0.2-inch (5.08 mm) in 5 feet (1.52 m). Surface defects on formed surfaces measured on a length of 5-inch (127 mm) not more than 0.1-inch (2.54 mm). (7) Compressive Strength. Compression tests to determine the minimum strength requirements shall be made on cylinders. A minimum of three cylinders will be made from each day's production and cured in the same manner as the precast units. Testing methods shall be in accordance with AASHTO Specifications T 22 and T 24. (8) Rejection. Units shall be subject to rejection because of failure to meet any of the requirements specified above. In addition any or all of the following defects shall be sufficient cause for rejection: a. Defects that indicate imperfect moulding. b. Defects indicating honeycombed or open texture concrete. (9) Marking. The date of manufacture shall be clearly scribed on the rear face of each panel. (10) Handling, Storage and Shipping. All units shall be handled, stored, and shipped in such manner as to eliminate the danger of chipping, cracks, fractures and excessive bending stresses. Panels in storage shall be supported on firm blocking located immediately adjacent to tie strips to avoid bending the tie strips. (11) Concrete Footing. Concrete shall conform to Section 602. (b) Steel Face Panels. Steel face panels shall be fabricated of cold rolled galvanized steel and conform to the plans and the minimum requirements of ASTM A446 Grade C or other approved material. Galvanization shall conform to the minimum requirements of ASTM A 525, Class G 210. (c) Reinforcing and Tie Strips. Reinforcing and tie strips shall be shop fabricated of galvanized steel, conforming to the minimum requirements of ASTM A 446 Grade C. Galvanization shall conform to the minimum requirements of ASTM A 525, Class G 210. They shall be cut to lengths and tolerances shown on the plans. Holes for bolts shall be punched in the location shown. Minimum bending radius of tie strips shall be 1-inch (25.4 mm). All reinforcing and tie strips shall be carefully inspected to insure they are true to size and free from defects that may impair their strength or durability. (d) Fasteners. Bolts and nuts shall be hexagonal cap screw S.A.E., Grade 5, nominal size 2-inch (12.70 mm) by 1-inch (25.40 mm) with a 34-inch (19.05 mm) thread length, hot dip galvanized. (e) Joint Filler. (For use with concrete face panels.) (1) Filler for vertical joints between panels shall be flexible open cell polyether foam strips, Grade 1035, 2-inch x 2-inch, (50.8 mm x 50.8 mm) conforming to the minimum requirements of ASTM D 1564. (2) Filler for horizontal joints between panels shall be resinbonded cork filler conforming to ASTM D 1752 (Type II) or equal as approved by the Engineer. Joint Covers. (For use with steel face panels.) Joint covers shall be fabricated of cold rolled galvanized steel and conform to the plans and the minimum requirements of ASTM A 446 Grade C. Galvanization shall conform to the minimum requirements of ASTM A 525, Class G 210. (g) Select Granular Backfill Material. All backfill material used in the structure volume shall be free from organic or otherwise deleterious materials and shall conform to the following gradation limits: Sieve size 10 inches (254.0 mm). No. 200 (75 μm) --. Percent passing 100 100-75 0-15 This material shall exhibit an angle of internal friction of not less than 25 degrees as determined by standard triaxial or direct shear testing methods. Material not conforming to these specifications shall not be used without the written consent of the Engineer. The Contractor, or the supplier as his agent, shall furnish the Engineer a Certificate of Compliance certifying the above materials comply with the applicable contract specifications. A copy of all test results performed by the Contractor or his supplier necessary to assure contract compliance shall also be furnished the Engineer. Acceptance will be based on the Certificate of Compliance, accompanying test reports, and visual inspection by the Engineer. Construction Requirements 613.03 Wall Excavation. Unclassified excavation shall be in accordance with the requirements of Section 203 and in reasonably close conformity to the limits and construction stages shown on the plans. 613.04 Foundation Preparation. The foundation for the structure shall be graded level for a width equal to or exceeding the length of reinforcing strips or as shown on the plans. Prior to wall construction, the foundation shall be compacted with a smooth wheel vibratory roller as provided under Section 212. (a) When concrete face panels are specified, at each panel foundation level, an unreinforced concrete leveling footing shall be provided as shown on the plans. The footing shall be cured a minimum of 12 hours before placement of wall panels. 613.05 Wall Erection. (a) Concrete face panels. Precast concrete panels shall be placed vertically with the aid of a light crane and lifting beam. For erection, panels are handled by means of eyes set into the upper edge of the panels. Panels should be placed in successive horizontal lifts in the sequence shown on the plans as backfill placement proceeds. As fill material is placed behind a panel, the panels should be maintained in vertical position by means of temporary wooden wedges placed in the joint at the junction of the two adjacent panels on the external side of the wall. External bracing may also be required for the initial lift. Vertical tolerances and alignment shall be 4-inch (6.35 mm)/10 feet (3.05 m). (b) Steel face panels. Skin elements are placed by hand in successive horizontal lifts as indicated on the plans. Backfill must be maintained no more than two skin elements below top of wall. Wooden wedges shall be placed at not more than 5-foot (1.52 m) centers between the skins on the exposed face to maintain verticality during backfilling. Batter boards shall be used to maintain verticality for the first five lifts. All wedges shall be removed as backfilling proceeds. A minimum of five lifts shall be supported by wedges at all times. 613.06 Backfill Placement. Backfill placement shall closely follow the erection of each lift of panels. At each reinforcing strip level, backfill should be roughly leveled before placing and bolting strips. As shown on the plans, reinforcing strips shall be placed normal to the face of the wall. The maximum lift thickness shall not exceed 10 inches (254.0 mm) (loose) and shall closely follow panel erection. The Contrac tor shall decrease this lift thickness if necessary to obtain the specified density. Backfill shall be compacted in accordance with subsection 203.19. Backfill compaction shall be accomplished without disturbance or distortion of reinforcing strips and panels. 613.07 Method of Measurement (a) Concrete face panels-The unit of measurement for furnishing and fabricating all materials for the walls, including concrete face panels, reinforcing and tie strips, fasteners, joint filler, and incidentals, will be the square foot. (b) Steel face panels-The unit of measurement for furnishing and fabricating all materials for the walls, including the steel face panels, reinforcing strips, fasteners, joint covers and incidentals, will be the linear foot. (c) The unit of measurement for wall erection will be the square foot. The quantity to be paid for will be the actual quantity erected in place at the site. Payment shall include compensation for all labor and materials required to prepare the wall foundation, put in place the reinforcing strips, and erect the panel elements to the lines and grade shown on the plans. For purposes of calculation each full size concrete face panel is equivalent to 24.2 square feet (2.25 m2). Each half size panel is the equivalent to 12.1 square feet (1.12 m2). (d) The unit of measurement for the concrete footing will be the number of linear feet, complete in place and accepted, measured along the line and grade of the footing. (e) The unit of measurement for the longitudinal reinforcing strips used for foundation strengthening will be the number of linear feet, complete in place and accepted. (f) Backfill-The unit of measurement for select granular backfill will be the embankment plan quantity cubic yards in accordance with subsection 109.01. Basis of Payment 613.08. The quantities, determined as provided above, will be paid for at the contract price per unit of measurement, respectively, for each pay item listed below and shown in the bid schedule, which prices and payment will be full compensation for the work prescribed in this section, except as provided in (1), (2), and (3) below: (1) Excavation will be measured and paid for as provided in Section 203. 207. (2) Water will be measured and paid for as provided in Section |