for Highway Construction Page 185 of 715 SECTION 302 – EMULSION TREATED BASE
302.01 Description.
Construct 1 or more courses of emulsion treated base.
302.02 Materials.
Provide aggregate as specified in 703. The Engineer will accept aggregate for quality requirements at the point of delivery. Provide emulsified asphalt of the type and grade as specified in 702. The Engineer w ill accept the material at the point of delivery. Use the following standard test methods: Compaction Standard for Coarse Granular Materials by Use of the Vibratory Spring- load Compactor ......................................................... Idaho IT 74 In-Place Density and M oisture Content of Soil and Soil Aggregate by Nuclear Methods (Shallow Depth) ................................................. AASHTO T 310 Method B Instead of Idaho IT 74, if approved, the maximum dry density of aggregate base may be tested with: Moisture Density Relations of Soils ..................................................... AASHTO T 180 Method D Prepare an Idaho IT 74 density curve or an AASHTO T 180 Method D moisture- density curve for the aggregate base and submit bef ore placement . This testing is incidental .
302.03 Construction Requirements.
Mix the aggregate , emulsified asphalt , and water in an approved stationary plant. Mix the emulsified asphalt with water at a ratio of 1:1 and uniformly mix with the aggregate base until approximately 4 percent diluted emulsified asphalt, by weight of dry aggregate, has been added. Additional water may be required to complete the mixing of the aggregate base and to facilitate compaction. Place the base material on the roadbed by means of an approved aggregate spreader. Do not exc eed a maximum compacted thickness of 0.5 foot for each layer. Construct the base in 2 or more layers of approximate equal thicknes s if the required compacted depth of the base exceeds 0.5 foot. The compacted depth of a single layer of the base may be increased to 0.8 foot when vibrating or other approved types of special compacting equipment are used. Shaping and spreading may be per formed with motor graders or approved methods in areas where it is not practical to operate the spreader. Compact for its full width after each layer has been spread and continue compaction until 100 percent of the applicable maximum density is attained. Produce a surface for each layer with uniform texture and aggregate that is firmly keyed. Maintain the surface during the compaction operations. for Highway Construction Page 186 of 715 302.04 Method of Measurement. The Engineer will measure acceptably completed work for emulsion treated base and emulsified asphalt by the ton. The Engineer will not use batch weights as a method of measurement. The Engineer will use the weight of the emulsion treated base quantity in the accepted base and will include the weight of aggregate and emulsified asphalt . The Engineer will deduct the weight of water and emulsified asphalt in excess of 7 percent of the weight of dry aggregate from the weight of the emulsion treated base.
302.05 Basis of Payment .
The Department will pay for accepted quantities as follows: Pay Item Pay Unit Emulsion T reated Base .......................................................................... Ton Emulsified Asphalt for Emulsion T reated Base ....................................... Ton for Highway Construction Page 187 of 71 5 SECTION 303 – AGGREGATE BASE
303.01 Description.
Provide, place, and construct 1 or more courses of aggregate on a prepared surface.
303.02 Materials.
Provide aggregate as specified in 703. The Department will accept the aggregate from the windrow or roadway. If purchased and stockpiled, acceptance will be at the crushing plant. The Contractor may use crushed glass in base. Uniformly blend the crushed glass with the aggregate. Ensure the glass -aggregate blend meets the aggregate gradation specified. The Contractor may use glass crushed to ¾ inch minus up to approximately 15 percent by weight of aggregate base . Place the glass -aggregate base material at least 1 foot below unpaved surfaces. The Contractor may use glass crushed to 5/16 inch minus up to approximately 15 percent by weight in aggregate base , with no restriction on location. Use the following standard methods for tests: Compaction Standard for Coarse Granular Materials by Use of the Vibratory Spring- load Compactor ......................................................... Idaho IT 74 In-Place Density and Moisture Content of Soil and Soil Aggregate by Nuclear Methods (Shallow Depth) ................................................. AASHTO T 310 Method B Instead of Idaho IT 74, if approved, the maximum dry density of aggregate base may be determined as follows: Moisture Density Relations of Soils ........................................................... AASHTO T 180 Method D Prepare and submit an Idaho IT 74 density curve or an AASHTO T 180 Method D moisture density curve for the aggregate base before placing. This testing is incidental .
303.03 Construction Require ments.
A.General. Do not exceed a maximum compacted thickness of 0.5 foot for each layer. Construct the base in 2 or more layers of approximate equal thickness if the required compacted thickness of the base exceeds 0.5 foot. The compacted t hickness of a single layer of the base may be increased to 0.8 foot when vibrating or other types of special compacting equipment are used with approval. After each layer has been spread, compact the layer for its full width. Continue compaction until at least 95 percent of the maximum dry density is attained. Determine the density of aggregate base in place in accordance with AASHTO T 310 Method B. Maintain the surface of each layer dur ing the compaction operations so a uniform texture is produced and the aggregate firmly keyed. Apply enough water uniformly over the base materials during compaction to ensure proper compaction is achieved.
Source: Idaho Standard Specifications for Highway Construction, 2023 Edition. Pages 221–222 of 768.