for Highway Construction Page 189 of 71 5 SECTION 304 – RECONDITIONING
304.01 Description.
Recondition the surface of an existing road, shape the shoulders, and dispose of surplus material.
304.02 Materials.
Not specified.
304.03 Construction Requirements.
Scarify the roadbed, including the shoulders to the depth and width specified. Pulverize the scarified material so 5 percent or less of this material, exclusive of gravel or stone, is retained on a 2 -inch sieve. Moisten and compact the pulverized material to the required density. Blade and water the surface, if directed, and continue blading and watering during the rolling operations. Satis factorily main tain the surface until the base or surface course has been placed. Apply additional water to prevent checking or raveling, if needed. Excavation and repair soft spots as specified in 205 .03.E .
304.04 Method of Measurement.
The Engineer will measure acceptably completed work as follows:
1.Reconditioning will be by the station or mile and will include blading of shoulders, scarifying and pulverizing of the existing roadbed, handling of existing asphalt mixtures, compaction of the roadbed, finishing of the surface, and maintenance of the completed surface.
2.At the Engineer’s request, randomly -selected empty transport ing vehicles may be w eighed on a local certified scale able to produce a scale ticket for the Engineer’s documentation and verification.
3.Water by the thousands of gallons (MG), where 1 MG equals 1,000 gallons, transported or conveyed by means of calibrated tanks or distributors or by means of accurate water meters. Only the water used in mixing materials or ordered to keep the surface moist will be measured for payment .
304.05 Basis of Payment .
The Department will pay for accepted quantities as follows: Pay Item Pay Unit Reconditioning ........................................................................................ Station or Mile Water for Reconditioning ........................................................................ MG Excavation of Soft Spots ......................................................................... CY Soft Spot Repair ..................................................................................... CY The Department will pay for removal and disposal of unsuitable material under excavation of soft spots. The Department will pay for backfill material used to replace unsuitable material under its respective item or as extra work (104.02) . The Department will not pay for the Contractor’s optional replacement material. 305-306 for Highway Construction Page 190 of 715 SECTIONS 305-306 - RESERVED for Highway Construction Page 191 of 71 5 SECTION 307 – OPEN- GRADED BASE
307.01 Description.
Construct 1 or more courses of open- graded base on a prepared surface.
307.02 Materials.
Provide material for open- graded base as specified in 703.
307.03 Construction Requirements.
Place the first layer of open- graded base directly over Type II subgrade separation geotextile in a lift of at least 12 inches thick but less than 18 inches thick. The minimum lift thickness is 6 inches and the maximum lift thickness is 12 inches above the initial lift. Compact the first layer with at least 6 full coverages and compact subsequent layers with at least 2 full coverages for each 6- inch lift thickness with a vibratory roller meeting the following requirements:
1.A rated minimum centrifugal force of 30,000 pounds per impact.
2.At least 1,000 vibrations per minute.
3.Operate at a speed less than 130 feet per minute. Do not allow equipment on the geotextile before placing the firs t lift of open -graded base. Do not dump the open- graded base directly on the geotextile. Dump the material on the previously placed lift and push ahead. Switch off the vibrators if there is evidenc e of the vibrating rollers causing excess movement, depressions, or voids other than what is considered normal compaction displacement until otherwise directed. During the compaction process, keep the open- graded base visibly moist. Keep soil, mud, or other undesirable fine material from accumulating on its surface once t he open- graded base is in place. If contamination does occur during the construction operation, replace material as directed at no cost to the Department. Place open- graded base Class III as specified in 303.
307.04 Method of Measurement.
The Engineer will measure acceptably completed work by the cubic yard, neat line measurement of the roadway section, or the ton.
307.05 Basis of Payment .
The Department will pay for acceptable quantities at the contract unit prices as follows: Pay Item Pay Unit Open- graded base Class ...................................................................... CY or Ton The Department will pay for geotextile under 640.
Source: Idaho Standard Specifications for Highway Construction, 2023 Edition. Pages 225–226 of 768.