- 794 - SECTION 1008 -- FLY ASH
1008.01 Description
1.Fly ash shall be Class C or F meeting the requirements of ASTM C 618.
1008.02 Material Characteristics
1.All fly ash will be acceptance tested by the Department. This includes production plant samples and field samples.
2.Fly ash shall conform to the requirements of Class C or Class F pozzolan as defined in ASTM C 618 except that the maximum loss on ignition for Class F pozzolan shall be 3.0%. Either class of fly ash shall not contain more than 1.5% of available alkalis as Na 2O.
3.Fly ash produced in furnace operations utilizing liming materials or soda ash (sodium carbonate) as an additive will not be acceptable.
1008.03 Procedures
1.Fly ash shall be protected, stored, handled, and sampled in the same manner as specified for Portland cement in Sections 1002 and 1004 and the Department’s Materials Sampling Guide .
2.Each shipment of fly ash sent to the project or ready mix plant shall be accompanied with a certificate of compliance from the supplier. The certificate must include the following information:
a.Name of the supplier.
b.Source of the fly ash.
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.
i.The Department’s specificat ions that the product is in compliance with.
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 fly ash meets the specification requirements of the Nebraska Department of transportation for Class _____ fly ash.” Signed ___________________________________ For ______________________________________ (Supplier)
4.Two copies of the certificate of compliance shall be sent with the shipment for the Engineer. The Engineer will retain one copy for his/her file and send the other copy to the Department’s Materials and Research Division to serve as notification of rece ipt and identification of the fly ash. Fly Ash 1008.04 - 795 - 5. Fly ash may be used as soon as it is received, provided it is accompanied by the proper certificat e of compliance and the results of previous tests indicate a satisfactory product.
1008.04 Acceptance Requirements
1.Approved fly ash will be on the Department’s Approved Products List. Fly ash may be added to the Department’s Approved Products List if it is in conformance with the Department’s Acc eptance Policy for Fly Ash. This information is available upon request from the Department's Concrete Materials Section.
2.Should any sample indicate nonc ompliance with the specifications, use of material from that source bas ed on certification only may be withheld. It will be necessary that the fly ash be held in special silos or bins at the generating plant or some facility under control of the company furnishing the fly ash until such time that test results show compliance. When it can be shown that c ontinuing production from that generating plant has a high assurance of meeting specifications, material acceptance may once again be based on certification only.
3.If tests made on field samples taken by the Department fail to meet any of the specification re quirements, all shipments from the supplier will be held until tests have been completed by the Department’s Materials and Research Division and approval for use is issued. This procedure will be continued until it can reasonably be assured that the fly ash from the supplier w ill again continue to meet contract requirements. - 796 - SECTION 1009 -- SILICA FUME
1009.01 Description
1.Silica fume is very fine pozzolanic material composed mostly of amorphous silica produced by electric arc furnaces as a by-product of the production of elemental silicon or ferro-silicon alloys.
1009.02 Material Characteristics
1.Silica fume shall conform to the requirements of ASTM C 1240, including the optional chemical and ph ysical requirements, except that the minimum SiO 2 shall be 90% by weight.
2.Silica fume in slurry form shall not be allowed.
1009.03 Procedures
1.The Contractor shall provide a dequate protection for the silica fume against dampness.
2.Silica fume shall be protected from temperatures in excess of 90°F (32C).
3.Silica fume shall be protected from exposure to direct sunlight.
4.Each shipment of silica fume sent to a project or ready mix plant shall be accompanied with a certific ate of compliance executed by the manufacturer. The certificate must include the following information:
a.The name of the manufacturer. b. The location of the manufacturer. c. The batch or lot number. d. The date of manufacture. e. The weight of the shipment.
f.The Department’s specificat ions that the product is in compliance with.
5.No silica fume which has become caked or lumpy shall be used. 6. Silica fume which has been spilled shall not be used. 1009.04 -- Acceptance Requirements
1.Silica fume approved for use is on the Department’s Approved Products List. The suppliers, in addition to providing a manufacturer's certification of compliance for each sh ipment, must submit certification annually to the Department’s Materials and Research Division stating that their product meets Depart ment’s specifications.
2.Silica fume that arrives wit hout proper certif ication shall be sampled, tested, and approved by the Department’s Materials and Research Division before use.
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 828–829 of 1,048.