- 971 - SECTION 1079 -- SLAG CEMENT FOR USE IN CONCRETE AND MORTARS
1079.01 Description
1.Slag Cement shall meet the requirements of ASTM C 989, Grade 100 or 120.
1079.02 Material Characteristics
1.All slag cement will be acceptance tested by the Department. This includes production plant samples and field samples.
1079.03 Procedures
1.Slag cement shall be protect ed, stored, handled, and sampled in the same manner as specified for Po rtland cement in Sections 1002 and 1004 and the Department’s Materials Sampling Guide.
2.Each shipment of slag cement s ent to the project or ready mix plant shall be accompanied with a Certificat e of Compliance from the supplier or manufacturing plant. The certificate mu st include the following information:
a.Name of the supplier or manufacture. b. Source of the slag cement. c. Consignee and desti nation of the shipment.
d.Project number to be used on, if available, and date shipped. e. Railroad car number or truck identification number.
f.Weight of the shipment.
g.Certified test number repres enting the material being shipped.
h.An unrepeated order number or other identification number so that each shipment is separately identified.
3.The following signed certificati on statement, or similar wording, must also be included on the form: “This is to certify that this shipment of slag cement meets the specification requirements of the Nebraska Departmen t of Transportation for slag cement, Grade 100 or 120”. Signed ____________________________________________ For _______________________________________________ (Supplier)
4.Two copies of the Certificate or Compliance shall be sent with the shipment to the ready mix plant or project. The concrete producer will retain one copy of the Certificate of Compli ance for their records and one will be collected by the Engineer if necessary.
5.Slag cement may be used as soon as it is received; provided it is accompanied by the proper Certificate of Compliance and the results of previous tests indicate a satisfactory product.
1079.04 Acceptance Requirements
1.a. Approved slag cement will be on the Department’s Approved Products List.
1079.04 Slag Cement for Use in Concrete and Mortars
- 972 - b. Slag cement may be added to the Department’s Approved Products List if it is in conformance with the Department ’s Acceptance Policy for slag cement.
2.a. Should any sample indicate noncompliance with the specifications, use of material from that source based on certification only may be withheld. It will be necessary that the slag cement be held in special silos or bins at the plant or some facility under control of the company furnishing the slag cement until such time that test results show compliance.
b.When it can be shown that continuing production from that plant has a high assurance of meeting specifications, material acceptance may once again be based on certification only.
3.a. If tests made on field samples taken by the Department fail to meet any of the specific ation requirements, all shipments from the supplier will be held until tests have been completed by the Department and approval for use is issued.
b.This procedure will be conti nued until it can reasonably be assured that the slag cement from the supplier will again continue to meet contract requirements. - 973 - SECTION 1080 -- WARM MIX ASPHALT
1080.01 Description
1.The Contractor has the option to use Warm Mix Asphalt (WMA) meeting the following requirements.
1080.02 Material Requirements
1.Warm Mix Asphalt (WMA)
a.Warm Mix Asphalt mixtures shall follow the requirements of Superpave Asphaltic Concrete and all ot her applicable sections with the following exceptions:
1.The Contractor shall request the use of a WMA additive in writing when submitting the Job Mix Formula. The requested additive shall be an approved Level I or II production product or combination thereof. The manufacturer’s recommended additive ra tes, specifications, and all other pertinent information shall be included in the requests. All requests must be approved by the Engineer prior to their use.
1080.03 Construction Methods
1.Level I Production
a.Level I WMA additives are as follows: water injection devices. b. Hydrated Lime at 1.25% by weight of virgin aggregate is required for all mixtures.
c.The allowable drop in temperature shall be a maximum of 40°F below the producer’s recommended production temperature for Hot Mix Asphalt (HMA), or less as required during production to achieve proper laydown and compaction properties. Plant production temperatures shall not drop below 230°F.
2.Level II Production a. Approved Level II WMA additives are listed on the Department’s Approved Products List.
b.For amine based WMA additives, 25% of the additive must be considered an amine based anti-stripping agent, unless Poly-Phosphoric Acid (PPA) is used. If PPA is used in the binder, the WMA shall be a non- amine based WMA, specifically fo r use and compatible with binders containing PPA. WMA additives and anti-strips shall be terminal blended by the binder supplier. For all other warm mix technologies hydrated lime shall be added at a minimum rate of 1.25% by weight of virgin aggregate, including the weight of limestone. Hy drated Lime shall not be used on Level II WMA mixtures when the WMA additive is an Amine based additive or when the Amine WMA additives are used in combination with Level I water injection. The minimum rate for amine based WMA additives shall be 0.7%. The dosage rate of anti-strip sh all not exceed manufacturer’s recommendations.
c.The drop in temperature shall be a maximum of 90°F from the producer’s recommended production temperature for HMA. Plant production temperatures shall not drop below 215°F.
3.Other WMA additives shall not be used unless otherwise approved by the Engineer.
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 1005–1006 of 1,048.