- 736 - SECTION 907 -- GABIONS AND REVET MATTRESSES
907.01 Description
1.The Contractor shall furnish, a ssemble, tie, and fill with approved stones mesh wire baskets constructed and placed in conformity with the lines, grades, and dimensions shown in the contract.
907.02 Material Requirement
1.Materials shall conform to t he requirements of Section 1074.
907.03 Construction Methods
1.The Contractor shall construct all gabion and revet mattress structures as shown in the contract.
2.All basket units shall be assembl ed by binding all adjacent vertical edges with basket connecting clips placed every 4 inches (100 mm).
3.Empty units shall be set to line and grade as shown in the contract. 4. Connecting clips shall be used to join the units together in the same manner as described above for assembling.
5.Internal connecting wires shall be uniformly spaced and securely fastened in each outside cell of the structure or where ordered by the Engineer.
6.A fence stretcher, chain fall, or iron rod may be used to stretch the wire baskets and hold alignment.
7.a. The baskets shall be filled wi th stone, carefully placed so that air void volume is minimized.
b.Hand placing of the rock-f ill shall be required on the exposed faces of the units so that the rock fill appears to be uniformly stacked.
c.The ledge rock shall be placed on its natural face surface rather than on the edge face.
d.After a basket has been filled, the lid shall be bent over until it meets the sides and edges.
8.Each basket shall be overfi lled approximately 2 inches (50 mm) above the sides before closing the lids. The lid shall then be secured to the sides, ends, and partitions with the connecting wire in the manner described above for assembling. Special attentio n shall be given to see that all projections or wire ends are turned into the baskets.
9.The Contractor shall also comp ly with all manufacturer installation requirements. The Contractor shall s ubmit the installation requirements to the Engineer two weeks prior to installation.
907.04 Method of Measurement
1.Gabions and revet mattresses shall be measured by the each.
907.05 Basis of Payment
1.P a y I t e m P a y U n i t Gabion, Type _____ Each (ea) Revet Mattress, Type _____ Each (ea) 2. Payment is full compensation for all work described in this Section. - 737 - SECTION 908 -- CONCRETE SLOPE PROTECTION, DITCH LINING, FLUMES AND DISCHARGE STRUCTURES
908.01 Description
1.The Contractor shall furnish all materials, prepare the subgrade, and construct the following as described in the contract:
a.Concrete slope protection.
b.Concrete ditch lining. c. Concrete flumes. d. Concrete discharge structures.
908.02 Material Requirements
1.Concrete shall be Class "47B-3000" (47B-20).
2.All materials shall conform to the requirements in Table 908.01. Table 908.01 Material Requirements Applicable Materials Section Concrete ........................................... 1002 Preformed Jo int Filler .............................. 1015 Reinforcin g Steel ..................................... 1020, 1022, 1023
908.03 Construction Methods
1.a. The Contractor shall pre pare the subgrade by trenching or filling to the required elevation.
b.The subgrade shall be thoroughly tamped. c. In cuts, the excavation shall be made sufficiently wide to allow placing of forms and performing the required placing and finishing work.
d.In fills, the su bgrade shall be made at least 1 foot (300 mm) wider on each side than required by the flumes or discharge structures. The subgrade shall be compacted to a minimum of Class I embankment or as shown in the contract.
e.The subgrade shall be excavated carefully in order that the finished grades conform to the neat lines of the bottom and slopes of the structure as shown in the contract.
f.No raised places or bumps will be allowed. Depressions left in the surface of the subgrade s hall be filled with concrete.
g.If necessary, water shall be added by sprinkling to facilitate compaction.
h.At the time concrete is deposited, the subgrade shall be thoroughly moistened. Water ponding on the surface will not be allowed.
i.Sand-fill, when required, shall be uniformly compacted. The moisture content shall be sufficient to allow sa tisfactory compaction.
2.Tie bars shall be placed at the locations shown in the contract. Tie bars shall be used in all concrete di scharge structures that are placed adjacent to the concrete pavement.
3.The forming requirements of Section 607 shall apply to this work.
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 770–770 of 1,048.