917-1 Composition.
Mineral filler shall consist, in general, of limerock dust, portland cement, slag dust, hydrated lime, or any other inert mineral matter from sources approved by, the Engineer. The mineral filler shall be thoroughly dry and free from lumps consisting of ag gregations of fine particles. Ground phosphate will not be allowed as a mineral filler. Stone or slag screenings may also be used as filler material for asphalt concrete mixtures, under the provisions specified in 917 -3, below.
917-2 Gradation.
The mineral filler shall meet the following gradation requirements: Total passing No. 30 sieve ................................ ........... 100% Total passing No. 80 sieve .......................... 95% (minimum) Total passing No. 200 sieve ........................ 65% (minimum)
917-3 Provision for Use of Coarser Filler Material.
Process screenings f rom stone or slag, having a coarser gradation than as specified above, may also be used as filler material provided the particular product, and the source thereof, are approved by the Engineer and that the material meets the following requirements.
1.All of the material shall pass the No. 10 sieve, and not more than 35% shall pass the No. 200 sieve.
2.The material passing the No. 200 sieve shall be free from organic impurities, and not more than 4.0% of such shall consist of clay minerals. The plastic ity index of the material passing the No. 200 sieve shall not exceed 4.
3.For the stone or slag material from which the screenings are produced the loss, when subjected to the Los Angeles Abrasion Test, shall not exceed 45%. FY 2023-24 Return to Table of Contents SECTION 919 GROUND TIRE RUBBER
919-1 Description.
This Section specifies the requirements for ground tire rubber (GTR).
919-2 General Requirements.
919-2.1 General: The GTR shall be produced from tires and shall be substantially free
from contaminants including fabric, metal, mineral, and other non -rubber substances. Up to 4% (by weight of rubber) of talc or other inert dusting agent, may be added to prevent sticking and caking of the particles.
919-2.2 Ground Tire Rubber (GTR) for Use in Asphalt Rubber Binder: GTR shall
be sufficiently dry so as to be free flowing and to prevent foaming when mixed with asphalt cement. The use of pelletized asphalt rubber is permit ted provided the components of the pelletized rubber particles meet the requirements of this Section. Additionally, the pelletized particles must disassociate once blended with asphalt cement.
919-2.3 Ground Tire Rubber (GTR) for Use in Flowable Fill: GTR may replace up to
20% of the fine aggregate.
919-2.4 Approved Product List (APL) : GTR and pelletized rubber used shall be one of
the products listed on the Department’s Approved Product List (APL). Manufacturers seeking evaluation of their product shall submit an application in accordance with Section 6.
919-3 Physical Requirements .
The physical properties of the ground tire rubber shall be determined in accordance with FM 5-559, and shall meet the following requirements: Specific Gravity ................................ ................. 1.02 to 1.20 Moisture Content ................................ .......Maximum 0.75% Metal Contaminants ................................ ...Maximum 0.01% Gradation .............. Minimum 98% Passing the No. 30 Sieve
919-4 Chemical Requirements.
The chemical composition of the ground tire rubber shall be determined in accordance with ASTM D297-13 and shall meet the following requirements: Acetone Extract ................................ .............Maximum 25% Rubber Hydrocarbon Content ............................... 40 to 60% Ash Content ................................ .................... Maximum 8% Carbon Black Content ................................ ........... 20 to 40% Natural Rubber ................................ ...................... 16 to 45%
919-5 Packaging and Identification Requirements.
The ground tire rubber shall be s upplied in moisture resistant packaging such as either disposable bags or other appropriate bulk containers. Each container or bag of ground tire rubber shall be labeled with the manufacturer’s designation for the rubber and the specific type, maximum nomi nal size, weight and manufacturer’s batch or LOT designation. FY 2023-24 Return to Table of Contents
Source: Florida Standard Specifications for Road and Bridge Construction, 2024 Edition. Pages 1004–1004 of 1,299.