FLEXIBLE -PAVEMENT MATERIALS (INCLUDING MATERIALS FOR STABILIZING) BASE AND STABILIZED BASE MATERIAL S
911-1 Description.
This Section governs materials to be used in the construction of base and subgrade stabilization including limerock, shell, shell -rock, cemented coquina shell , and recycled concrete aggregate (RCA).
911-2 Materials.
911-2.1 General:
911-2.1 1 Approval of Material: Approval of mineral aggregate sources shall be
in accordance with 6 -2.3.
911-2.1 2 Deleterious Substances: Materials shall not contain deleterious
substances that would result in: prevention of the bituminous prime coat from adhering to the base course; a detriment to the finishing, strength, or performance of the base ; or a surface which is susceptible to distortion under construction traffic . Such substances include, but are not limited to: cherty or other extremely hard pieces, lumps, balls or pockets of sand or clay size material, organic matter, loose sand, loose, free shells, corals or skeletal remain of other marine invertebrates retained on the No. 4 sieve, or water sensitive clay minerals.
911-2.2 Limerock Composition: Limerock material shall consist of unconsolidated or
partly consolidated limestone of marine origi n.
911-2.3 Shell Material: Composition: Shell materials shall consist of naturally
occurring deposits formed essentially of broken mollusk shell, corals and the skeletal remains of other marine invertebrates. Live or steamed shell, or man -made deposits as a by-product of the shellfish industry will not be permitted.
911-2.3 1 Bank Run Shell: Shell materials meeting the requirements of this
Section which are presently found as “dry land” deposits.
911-2.3 2 Dredged Shell: Shell materials meeting the req uirements of this
Section which are dredged from ocean, bay or lake deposits.
911-2.4 Shell-Rock Material Composition: Shell-rock materials shall consist of
naturally occurring heterogeneous deposits of limestone with interbedded layers or lenses of loose and cemented shell, to include cemented sands (calcitic sandstone). This material shall be mined and processed in a manner that will result in a reasonably homogenous finished product.
911-2.5 Cemented Coquina Shell Material Composition: Cemented coquina shell
materials to be used as cemented coquina base or stabilized base, shall be defined as naturally occurring deposits formed essentially of broken mollusk shell, corals and the skeletal rema ins of other marine invertebrates, which are presently found as “dry land” deposits and which have been cemented together by carbonates or other natural cementing agents.
911-2.6 Recycled Concrete Aggregate (RCA) Composition: RCA shall consist of
concrete material derived from the crushing of hard portland cement concrete. In addition to the deleterious materials noted in 911 -2.1.2, RCA shall be asbestos free. The following limits shall not be exceeded: FY 2023-24 Return to Table of Contents Bituminous Concrete ................................ ...... 1% by weight Bricks ................................ .............................. 1% by weigh t Glass and Ceramics ................................ ......... 1% by weight Wood and other organic substances ............. 0.1% by weight Reinforcing steel and welded wire fabric .... 0.1% by weight Plaster and gypsum board ............................ 0.1% by weight
911-3 Material Requirements .
911-3.1 Limerock Bearing Ratio (LBR): Materials shall meet the requirements in
Table 911-1 in accordance with FM 5-515: Table 911-1 Limerock Bearing Ratio (LBR) Material Requirement Limerock Average Results per LOT - 100, minimum Individual Results - 90, minimum Shell Shell-Rock Cemented Coquina Shell RCA Individual Results - 150, minimum
911-3.2 Liquid Limit and Plasticity : Materials shall meet the requirements in
Table 911-2 in accordance with AASHTO T 89 and AASHTO T 90: Table 911-2 Liquid Limit and Plastic Properties Material Liquid Limit Plastic Properties Limerock Base Not to exceed 35 Non-Plastic (NP) Stabilized Base Plasticity not to exceed 10 Shell - NP Shell-Rock Cemented Coquina Shell - NP RCA - NP
911-3.3 Carbonates : Materials shall meet the carbonate requirements in Table 911-3 in
accordance with FM 5-514: Table 911-3 Percentage of Carbonates (Calcium and Magnesium) Material Requirement Limerock minimum - 70% Shell minimum - 50% Shell-Rock minimum - 50% Cemented Coquina Shell minimum - 50% RCA Not Applicable FY 2023-24 Return to Table of Contents
911-3.4 Gradation and Size Requirements: Materials shall meet the gradation and size
requirements in Table 911-4 in accordance with FM 1-T27 and FM 1-T11: Table 911-4(1) Gradation Requirements Material Requirement Limerock Base At least 97% shall pass a 3 -1/2 inch sieve(2) Stabilized Base At least 97% shall pass a 1-1/2 inch sieve(2) Shell Dredged shell Passing 3 -1/2 inch sieve - 97% Passing No. 4 sieve - 50%, maximum Passing No. 200 sieve - maximum 7.5% (washed) Bank-run shell Passing 3 -1/2 inch sieve - 97% Passing No. 4 sieve - 80%, maximum Passing No. 200 sieve - 20%, maximum ( washed) Shell-Rock Passing 3 -1/2 inch sieve - 97%, minimum Passing No. 4 sieve - 70%, maximum Passing No. 200 sieve - 20%, maximum (washed) Cemented Coquina Shell RCA Sieve Size Percent by Weight Passing 2 inch 100 3/4 inch 65 to 95 3/8 inch 40 to 85 No. 4 25 to 65 No. 10 20 to 50 No. 50 5 to 30 No. 200 0 to 10
1.The maximum dimension shall not exceed six inches.
2.The material shall be well graded down to dust. The fine material shall consist entirely of dust of fracture.
911-4 Exceptions, Additions, and Restrictions .
Approved materials shall not be mixed with other approved or non -approved materials . FY 2023-24 Return to Table of Contents SECTION 914 STABILIZATION MATERIALS
914-1 General.
This Section governs materials to be used in subgrade stabilization. Meet the following requirements: Table 914-1 Plasticity Index (AASHTO T 90) Maximum 10 Liquid Limit (AASHTO T 89) Maximum 40 Passing a 3 -1/2 inch screen (AASHTO T 27) Minimum 97% LBR No Requirement
914-2 Materials for Stabilizing (Limerock Bearing Ratio -LBR).
914-2.1 Commercial Materials : Materials may be either limerock, shell rock, cemented
coquina or shell base sources approved in accordance with 6 -2.3.
914-2.2 Local Materials: Local materials used for stabilizing may be soils or recyclable
materials such as crushed concrete, roof tiles and asphalt coated base, reclaimed asphalt pavement (RAP) or Fossil Fuel Combustion Products (FFCPs) provided the following limits for organic content are met . Table 914-2 Average Organic Content* (FM 1-T267) Maximum 2.5% Individual Organic Content Sample (FM 1-T267) Maximum 4% *Note: A minimu m of three samples per source . FFCPs may be used provided they meet the requirements of 403.7047, F.S., are not used outside the paved area and are not less than 3 feet above the design high groundwater table. All materials for stabilizing must meet all applicable air or water quality standards or criteria in Florida Department of Environmental Protection (FDEP) rules . FY 2023-24 Return to Table of Contents
Source: Florida Standard Specifications for Road and Bridge Construction, 2024 Edition. Pages 995–997 of 1,299.