for Highway Construction Page 240 of 71 5 SECTION 408 – FOG COAT
408.01 Description.
Apply a fog coat and blotter , if required.
408.02 Materials.
Provide fog coat material that is diluted emulsified asphalt . Provide the emulsified asphalt as specified in 702 . Mix approximately equal volumes of emulsified asphalt and water before application. Provide blotter material as specified in 703. The Engineer will determine acceptability of material from the Contractor -provided sources at the point of delivery and at the source from designated sources.
408.03 Construction Requirements.
A.Equipment. Provid e equipment for applying the fog coat as specified in 406.03.B and blotter material as specified in 402.03.
B.Application of Fog Coat . Apply fog coat material with a pressure distributor in a uniform, continuous spread. Ensure the distributor does not exceed 25 mph. Do not exceed the specified asphalt applicatio n rate at the junction of the spread overlap. Correct skipped areas or defic iencies. Obtain approval for the quantities, rate of application, and temperature of the fog coat material before applying the fog coat. Do not apply the fog coat if surface or weather conditions prevent proper construction. Apply the fog coat so there is the least amount of inconvenience to traffic and to allow 1-way traffic without pickup or tracking. Apply the fog coat on the roadway in the same direction as traffic travels. Place fog coat over a seal coat within 1 working day of the completed seal coat or as conditions allow.
C.Application of Blotter . Spread blotter at the approved rate to absorb the excess asphalt if the fog coat material does not penetrate and the roadway must be used by traffic.
408.04 Method of Measurement.
The Engineer will measure acceptably completed work as follows:
1.Diluted emulsified asphalt by the gallon after dilution with no correction for temperature.
2.Blotter by the ton or cubic yard.
408.05 Basis of Payment .
The Department will pay for accepted quantities at the contract unit prices as follows: Pay Item Pay Unit Diluted Emulsified Asphalt for Fog Coat ................................................. gal for Highway Construction Page 241 of 715 Blotter ..................................................................................................... Ton or CY for Highway Construction Page 242 of 71 5 SECTION 409 – PORTLAND CEMENT CONCRETE PAVEMENT
409.01 Description.
Construct a portland cement concrete pavement as specified. Submit a proposed mix design. The Engineer will review the mix design for compliance with the specifications.
A.Classification . Proportion the materials for concrete to produce a workable concrete mix as specified in Table 409.01-1 . Table 409.01- 1 – Basic Mix Design Parameters Concrete Class in 100 psi (28 Day) (a) (b) (g) Minimum Cementitious Content lb/yd3 (c) (d) (e) (f) Water to Cement Ratio Slump in Air Content Percent 45 600 0.42 maximum 2 maximum 4 - 7
a.The class of concrete is the specified compressive strength when using the applicable tests as specified in 409.02.
b.A design value of 5,600 psi is specified to achieve the specified compressive strength.
c.Cement itious is cement plus secondary cementitious material (SCM).
d.It may not always be possible to produce concrete of the required strength using the minimum cementitious contents. No separate payment will be made by the Department for additional cementitious material required to meet specified strength.
e.Use SCM as specified in 714.
f.It may not always be possible to produce concrete using the minimum SCM content that will ensure mortar bar expansion does not ex ceed the standard limit when tested in accordance with CRD C 662 or ASTM C 1293. If additional SCM is needed to meet mortar bar expansion requirements, the Contractor may add it to the mix without a corresponding increase in cement provided the strength requirements are met. Obtain approval to add lithium or other mitigating measures to meet the mortar bar expansion requirement. A separate payment will not be made by the Department for additional cementitious material required to meet the specified compressive strength. The alkali content of the concrete must be kept below 3.0 lb/yd3 Na2Oe.
g.Concrete class designated as Class F will contain SCM. Minimum SCM content varies by product, for fly ash and slag cement (slag) minimum content is 20% by weight of total cementitious material. Fly ash will not exceed 25% of total cementitious material. Slag will not exceed 35% of the total cementitious material. Ternary and quaternary blends will contain at least 20% SCM. Total SCM content will not exceed 50%.
B.Acceptance. Concrete acceptance is based on compliance with parameters specified for paving concrete. Strength is accepted based on the results of the 28- day compressive strength tests determined in accordance with AASHTO T 22. The average strength of 3 companion cylinders is 1 test. When the 28- day strength for a test falls below the specified strength, concrete represented by that test is subject to rejection or a price adjustment . The Engineer may accept paving concrete at a reduced price, if the strength is within 10 percent of the spec ified strength. Concrete represented by tests more than 10 percent below specified strength is subject to rejection. Remove unacceptable concrete at no additional cost to the Department. The Engineer will use Table 409.01- 2 to determine the unit price adjustment of failing paving concrete allowed to remain in place.
Source: Idaho Standard Specifications for Highway Construction, 2023 Edition. Pages 276–277 of 768.