FDOT Section 911

Lime Rock Base Calculator — Florida FDOT Specifications

Q: What is Florida Limerock Base?

Florida Limerock is a soft, high-carbonate oolitic limestone aggregate certified under FDOT Section 911. When wetted and vibrated, its calcium carbonate dust dissolves into a slurry that hardens into an unyielding, high-bearing road base (LBR 100+).

Q: Why is an asphalt prime coat required over limerock base?

Limerock is sensitive to heavy surface water penetration before paving. Applying a penetrating liquid asphalt prime coat seals the compacted lime surface, preventing rain from washing out fines before the final asphalt surface is paved.

Florida Limerock Base (FDOT Section 911 / Miami Oolite) is the primary road foundation material in Florida, engineered for high moisture tolerance and 100+ Limerock Bearing Ratio (LBR).

ASTM / AASHTO Verified

Compaction & Waste Factors Included

Dump Truck Capacity Dispatcher

Imperial Standard (yd³ & Tons)

Lime Rock Base Calculator — Florida FDOT Specifications

Precision volume, tonnage, compaction shrinkage & dump truck dispatcher

FDOT Section 911

1. Excavation Area & Compacted Depth

Length (ft)

Width (ft)

Compacted Depth (in)

Project Presets:

2. Compaction Shrinkage (%)

3. Grading & Waste Buffer (%)

Geotechnical Material Density: 135 lb/ft³ (1.82 Tons/yd³)

Compacted Dry Density (lb/ft³)

Material Price ($/Ton)

Material Estimation Output

Total Weight to Order (incl. buffers)

25.1

Tons (approx. 1.3 Tri-Axle Loads)

Compacted In-Place Vol 11.1 yd³ 300 cu ft in place

Loose Delivery Volume 13.8 yd³ +24% combined buffer

Lift Schedule 2 Lifts (3.8" ea) 7.5" total loose spread

Material Subtotal $778.00 Excl. freight & taxes

Engineering Recommendation:

For a 6.0" compacted Lime Rock Base Calculator base, spread in 2 separate loose lifts of 3.8". Mist with water to achieve optimum compaction before running a 3,000+ lb plate compactor.

FDOT Highway Standard

FDOT Section 911 Oolitic Limerock Engineering Specifications

FDOT Section 911 / FM 5-515

Compacted Dry Density 134 lb/ft³ (2,146 kg/m³)

Weight per Volume 1.81 Tons / yd³

Sieve Gradation 3-1/2" Down to Carbonate Dust

Compaction Factor +18% to +22%

Optimum Moisture (OMC) 9.0% – 12.0% by Weight

CBR Bearing Ratio LBR 100+ (High Florida Bearing)

Governing Standard FDOT Standard Specifications Section 911

Max Lift Thickness 4" to 6" Maximum per Pass

Calcium Carbonate (CaCO3) 70% Minimum CaCO3 + MgCO3

Liquid Limit Non-Plastic (FM 1-T 089)

LBR Bearing Ratio LBR > 100 (FM 5-515)

Civil Engineering Math

How to Calculate Florida Limerock Base Tonnage, LBR Conversions & Loads

Mathematical equations for Florida limerock volume conversions, compaction shrinkage (+18–22%), and dump truck fleet distribution.

1 Surface Area

Area Geometry

Area = Length (ft) × Width (ft)

Determine the square footprint of your driveway, patio, slab, or pad. For curved shapes, break the area into offset rectangles.

2 In-Place Volume

Compact Volume

Vol (yd³) = (Area × Depth_in ÷ 12) ÷ 27

Convert design depth to volumetric units. This represents the final solid in-place compacted volume required after rolling.

3 Compaction Loss

Gross Loose Volume

Loose Vol = Compact Vol × (1 + 20%)

Quarries sell aggregate in its loose, aerated state. Adding 20% accounts for void compression under mechanical vibration.

4 Weight & Ordering

Quarry Tonnage

Tons = Vol (yd³) × 1.82 × 1.05 Waste

Convert volume to bulk weight using dense-graded stone density, adding 5% for site grading tolerance and edge bevel waste.

Real-World Numerical Example

Worked Calculation: 1,000 sq ft Driveway at 6" Compacted Depth

Target Material: Lime Rock Base Calculator

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Step 1 — Calculate In-Place Volume:

1,000 sq ft × (6 ÷ 12 ft) = 500 cu ft ÷ 27 = 18.52 cubic yards

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Step 2 — Apply +20% Compaction & +5% Waste:

18.52 yd³ × 1.20 (shrinkage) × 1.05 (waste) = 22.95 loose cubic yards

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Step 3 — Multiply by Quarry Bulk Density (1.81 Tons / yd³):

18.52 compacted yd³ × 1.24 combined factor × 1.82 Tons/yd³ = 41.8 Tons total order weight

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Step 4 — Calculate Hauling & Estimated Material Cost:

42 Tons ÷ 20-ton Tri-Axle = 3 Dump Truck Loads | Quarry Stone Cost: ~$1176

Order Sheet Summary

Total Order Weight: 41.8 Tons

Loose Volume: 23.0 yd³

Truckloads Required: 3 Tri-Axle Loads

Estimated Quarry Price: $1176

FDOT FM 1-T 027 Sieve Standard

FDOT Miami Oolite Limerock Particle Distribution & Carbonate Sieve Test

Laboratory grain-size analysis for Florida limerock base with mandatory 70%+ calcium and magnesium carbonate purity.

Standard Sieve Size % Passing (Design Target)

1 3-1/2" (90.0 mm)

Spec: 100% 100%

2 2" (50.0 mm)

Spec: 80% – 100% 90%

3 1/2" (12.5 mm)

Spec: 45% – 75% 60%

4 No. 4 (4.75 mm)

Spec: 30% – 60% 45%

5 No. 200 (75 µm)

Spec: 5% – 20% 12%

Selected Sieve Analysis Spec: 100%

3-1/2" (90.0 mm)

Target Percent Passing

100%

Geotechnical Function:

Maximum top size for FDOT Section 911 limerock.

Dense-Grading Principle: Continuous particle distribution from top size to sub-75µm fines locks stone voids, reducing empty space from 35% to <12% under vibration.

Civil Estimating & Geotechnical Engineering Review

Peer-Verified

Formulas, density conversions, and lift recommendations are modeled after AASHTO M147 (Materials for Aggregate and Soil-Aggregate Subbase) and ASTM C33/D2922 standards. Reviewed by licensed civil engineers and heavy highway earthwork estimators.

• AASHTO M147 Compliant • ASTM C136 Sieve Analysis • ASTM D698 / D1557 Proctor Compaction

Coastal Pavement Section

Florida High-Water-Table Pavement Profile: Limerock Subgrade Section

Cross-sectional structural layer breakdown for Florida coastal roads, sandy subgrades, and high-water-table conditions.

FDOT Asphalt Friction Course (FC-9.5 / FC-12.5)

Superpave Hot Mix Asphalt

1.5" – 2.0" Surface Course

Asphalt Prime Coat

EPR-1 or Prime Asphalt

0.10–0.15 gal/yd² Penetrating Seal

FDOT Limerock Base Course (Compacted)

Miami Oolite Limerock (LBR 100)

6.0" – 8.0" 98% AASHTO T180

Stabilized Subgrade Course

Limerock Stabilized Native Sand (LBR 40)

12.0" Compacted 98% AASHTO T180

Native Florida Sugar Sand Subgrade

Clean Fine Sand (AASHTO A-3)

Unbound Native Proof-Rolled Subgrade

Layer Inspection 1.5" – 2.0"

FDOT Asphalt Friction Course (FC-9.5 / FC-12.5)

Superpave Hot Mix Asphalt

Compaction Standard: Surface Course

Engineering Function & Placement:

Waterproof asphalt surface course preventing water penetration.

Subgrade Rule: Never place aggregate over uncompacted or organic subsoil. Proof-roll native soil with a loaded dump truck before laying the geotextile separation membrane.

Structural Depth Schedules

FDOT Limerock Thickness Guide for Sandy Soils & Coastal Subgrades

Recommended layer thicknesses for Florida residential driveways, parking lots, and FDOT roadway foundations over sandy soils.

Structural Depth & Lift Schedule by Use Case

Recommended compacted thickness and placement lift sequences

AASHTO / ICPI Guidelines

Project Application	Recommended Depth	Lift Sequence	Target Compaction	Engineering Note
Pedestrian Walkways & Garden Paths	3.0 – 4.0 inches	1 Lift (3–4" loose)	95% Standard Proctor	Edge restraints recommended to prevent foot-traffic gravel scatter. Geotextile optional on firm soil.
Paver Patio & Outdoor Living Slabs	4.0 – 6.0 inches	1–2 Lifts (3" compacted each)	98% Modified Proctor	Top with 1.0 inch of ASTM C33 concrete bedding sand. Screed flat without compacting sand prior to paver placement.
Light Residential Driveways (Cars & SUVs)	6.0 inches	2 Lifts (3" compacted each)	98% Modified Proctor	Crown driveway 1/4" per foot from center to edges. Install 4–6 oz non-woven geotextile over clay subgrades.
Heavy Vehicle, RV & Boat Storage Pads	8.0 – 10.0 inches	3 Lifts (3" compacted each)	100% Modified Proctor	Over-excavate pad footprint 12 inches beyond parked tire footprint for lateral edge confinement.
Shed, Pole Barn & Equipment Foundations	5.0 – 6.0 inches	2 Lifts (3" compacted each)	98% Modified Proctor	Extend gravel pad 12–18 inches beyond shed drip edge to capture roof runoff without foundation erosion.
Commercial Parking Lots & Highway Sub-Base	10.0 – 14.0 inches	3–4 Lifts (3–4" compacted each)	100% AASHTO T180	Requires proof-roll QA testing with loaded dump truck (20-ton axle) and nuclear density gauge verification.

Geotechnical Subgrade Rule

Subgrade Soil Adjustments & Geotextile Requirements

ASTM D1883 Subgrade Evaluation

CBR > 15%

Dense Gravel / Coarse Sand Subgrade

Base Depth Mod: Standard design depth (0" added)

Geotextile: Optional / Not Required

CBR 6% – 10%

Firm Silt / Sandy Loam Subgrade

Base Depth Mod: +1.0 to +2.0 inches extra base

Geotextile: Recommended (4 oz Fabric)

CBR 2% – 4%

Expansive Clay / Black Cotton Soil

Base Depth Mod: +2.0 to +4.0 inches extra base

Geotextile: Mandatory (6 oz Non-Woven Geotextile)

CBR < 2%

Wet Saturated / Organic Muck Subgrade

Base Depth Mod: +4.0" to +6.0" Base + 4" Surge Stone

Geotextile: Mandatory (Class 1 Geotextile + Biaxial Geogrid)

FDOT FM 5-515 / Proctor Lab

Limerock Compaction Mechanics: 100% LBR 100 & Slurry Grouting Physics

Moisture-density simulator showing how 10.5% moisture produces an impermeable slurry that seals limerock voids to 98% Modified Proctor density.

1. Loose Lift Thickness (Inches) 4.0" Loose Lift

2.0" (Hand Tamper) 4.0" (Max Plate Compactor) 6.0" (Small Roller) 8.0" (Heavy 5-Ton Roller)

2. Moisture Content (% by Dry Weight) 10.5% OMC (Optimum)

2% (Too Dry / Friction) 10.5% (Optimum Peak) 12% (Over-Saturated / Pumping)

Compaction Result: Optimal 98% Proctor

At 10.5% moisture and 4.0" loose lift, stone dust particles lubricate under vibration, packing completely into rock voids without excess pore water pressure.

Field Compaction Parameters

Target Proctor Density: 98% Modified Proctor (AASHTO T180 / FM 5-515)

Compaction Shrinkage: +20% extra loose volume

Water Dosage per 100 sq ft: ~25 Gallons

Compactor Passes: 6 to 8 passes with heavy vibratory steel roller

Recommended Machinery:

5-to-10 ton vibratory smooth drum roller with active drum sprayers.

Florida Hauling Logistics

Florida Dump Truck Fleet Dispatcher & Sandy Site Access Guide

Calculate Florida dump truckloads (tandem, tri-axle, dump trailer) and evaluate site access over soft Florida sand subgrades.

Selected Vehicle Specification

Tri-Axle Commercial Dump Truck

Most economical rate per ton (Contractor standard)

Payload Weight 18–22 Tons

Payload Volume 11–13.5 yd³

Clear Gate Width 12 ft Min

Overhead Wire Clear 24 ft Raised

Site Access Rule: A loaded tri-axle weighs ~65,000 lbs (32.5 tons gross). Ensure driveway culverts and bridges are rated for this axle weight before scheduling delivery.

Delivery Site Checklist:

Check overhead tree branches and power/phone wires.

Mark septic tanks, leach fields, and sprinkler heads.

Never dump on a cross-slope >8% (dump bed tip-over risk).

Have driver tailgate-spread stone in a thin pass to save shovel time.

Budget & Labor Estimator

Florida Quarry Limerock Pricing, Freight & Driveway Budget Simulator

Estimate Florida quarry direct rates ($22–$36/ton), local hauling fees, plate compactor rentals, and asphalt contractor paving quotes.

1. Total Project Area (Square Feet) 1,000 sq ft

100 sq ft (Walkway) 600 sq ft (2-Car Pad) 1,200 sq ft (Driveway) 10,000 sq ft (Acre Lane)

2. Material Quarry Price ($ / Ton) $28 / Ton

$15/Ton (Pit Direct Caliche/RCA) $28/Ton (Avg Crusher Run) $75/Ton (Imported Granite)

Equipment & Hauling Options:

Delivery Fee (per truckload)

Equipment Rental

DIY vs Contractor Cost Comparison

DIY Total Cost (Materials + Rental + Delivery)

$1,444

~$1.44 per square foot

Contractor Turnkey Cost (Excavation + Install + Base)

$5,500

~$5.50 per square foot ($4.50 – $7.50 / sq ft range)

DIY Labor Savings: You save approximately $4,056 in contractor excavation and installation labor on this project.

Material Selection Matrix

Florida Limerock vs. Coquina, Shell Rock & Recycled Concrete Base

Compare FDOT Oolitic Limerock, Coquina Shell Rock, Crushed Concrete (RCA), and Bank Run Shell.

Material Type	CBR Bearing Ratio	Compacted Density	Permeability	Avg Cost / Ton	Recommended Application
Florida Oolitic Limerock This Page	LBR 100+	134 lb/ft³	Impermeable (Slurry Sealed)	$24 – $32	Florida highways, driveways, commercial parking lots, building pads
Coquina / Shell Rock Base	LBR 80 – 100	128 lb/ft³	Low	$26 – $36	Coastal residential driveways, rustic Florida paths, unpaved lanes
Crushed Recycled Concrete (RCA)	LBR 100+	125 lb/ft³	Low-Moderate	$18 – $26	Commercial parking sub-base, budget pads, heavy equipment yards
Bank Run Shell	LBR 60 – 80	120 lb/ft³	Moderate	$28 – $40	Decorative coastal driveways, boat ramps, walkways

Quality Assurance & Failure Prevention

Florida Limerock Field QA: Limerock Bearing Ratio (LBR), Moisture Slurry & Primer

Execution Procedure: Attempt to drive a standard 1/2-inch (#4) steel rebar or probe into the compacted base using hand pressure.

Pass: Rebar cannot penetrate deeper than 1/2 inch into the stone matrix without a sledgehammer. Fail: Rebar easily slides into base deeper than 2 inches.

Troubleshooting Protocols

Common Road Base Failure Modes & Remediation

Field Repair Checklist

Soft, Spongy Pumping Under Compactor

Critical Severity

Root Cause:

Over-saturation of aggregate or wet, uncompacted native clay subgrade underneath.

Contractor Solution & Fix:

Stop rolling immediately. Allow surface to dry in the sun for 24–48 hours. If subgrade clay is pumping, excavate 4" deeper, install non-woven geotextile fabric, and place 3" of clean surge rock before re-laying base.

Surface Washboarding, Ravelling & Loose Dust

Moderate Severity

Root Cause:

Aggregate was rolled bone-dry without water lubrication, causing surface particles to shear instead of lock.

Contractor Solution & Fix:

Heavily mist surface with garden hose or water truck spray bar to 6%–7% OMC. Scarify top 2 inches with grader teeth or rake, then make 4–6 overlapping passes with a vibratory plate compactor.

Deep Wheel Rutting in Tire Tracks

High Severity

Root Cause:

Lift thickness was spread too deep (> 4.5" loose), resulting in dense top crust over loose bottom aggregate.

Contractor Solution & Fix:

Excavate rutted section. Re-place material in thin loose lifts not exceeding 3.5 to 4.0 inches per pass, compacting each lift to 98% Proctor before spreading the next.

Edge Blowout & Shoulder Erosion

Moderate Severity

Root Cause:

Comprehensive technical reference on Miami Oolite carbonate geology, Limerock Bearing Ratio testing, and high-water-table stabilization.

Florida Testing Standard Civil Standard Section 01

The Limerock Bearing Ratio (LBR) and Florida Oolite Geology

In Florida civil engineering, pavement strength is measured using the Limerock Bearing Ratio (Florida Test Method FM 5-515) rather than the standard California Bearing Ratio (CBR). The test benchmarks penetration resistance against a standard crushed Miami Oolite limerock sample defined as LBR 100 (which corresponds to CBR ≈ 80%). FDOT Section 911 mandates that all structural limerock base material must achieve a minimum LBR of 100, contain at least 70% calcium and magnesium carbonate (CaCO3 + MgCO3), and be completely non-plastic.

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