Company Services & Solutions
- Rollcon LLC: Recognized as a premier Roller Compacted Concrete (RCC) contractor in the U.S., offering turnkey planning, design, and construction services.
- Turnkey Services: A comprehensive project delivery method where Rollcon handles everything from planning and design to the final construction of paving projects.
- Roller Compacted Concrete (RCC): A zero-slump, high-density mixture of aggregates, water, and cement (or supplementary cementitious materials) that is placed using conventional asphalt paving equipment and compacted immediately by heavy vibratory rollers. Designed for heavy-duty applications due to its high early strength and durability, typically achieving design strengths of 3,000 to 5,500 psi. RCC offers a high-speed construction solution with low lifecycle costs.
- Cement-Treated Base (CTB): A mixture of aggregate or granular soils combined with Portland cement and water, used as a high-strength base for highways and industrial yards.
- Cement-Modified Soil (CMS): Soil treated with a relatively small proportion of Portland cement to amend undesirable properties of problem soils.
- Soil Stabilization: The process of treating subgrade soils (often with cement or lime) to improve engineering properties and suitability for construction.
- Pervious Concrete: A paving solution offered by Rollcon that allows water to pass through, reducing runoff and managing stormwater.
- Zero-Slump Concrete: A term Rollcon uses to describe RCC, emphasizing its stiffness and ability to be placed without forms, similar to asphalt.
- Dual-Lift Construction: A paving technique where two layers of RCC are placed sequentially (11 to 20 inches in total thickness) to achieve greater depth and structural integrity.
- Design-Build: A project delivery system implied by Rollcon’s capability to provide “complete planning, design, and construction services” in-house.
- Industrial Paving: A core service sector for Rollcon, focusing on refineries, manufacturing plants, and heavy-duty storage facilities.
Market Sectors & Applications
- Data Center & Mission Critical: An immerging market that utilizes RCC for the rapid speed of construction and high durability
- Port & Intermodal: A primary market sector for Rollcon, involving heavy-duty pavements for shipping terminals and rail yards.
- Distribution & Manufacturing: A key client sector requiring large-scale, durable pavements for logistics centers and warehouses.
- Energy & Industrial: Paving applications for power plants, refineries, and other energy infrastructure.
- Residential Developments: The use of RCC for neighborhood streets, notably in large-scale subdivisions like Colony Ridge.
- Heavy-Haul Roads: Roadways designed to support extreme loads from industrial transport and logging equipment.
- Logistics Center: Large-scale distribution hubs, such as the Walmart Distribution Centers, which utilize massive areas of RCC paving.
- Scrap Yards: Industrial facilities that benefit from RCC’s resistance to heavy impact and metal abrasion.
- Container Yards: Areas in port terminals (e.g., Port Houston) specifically paved with RCC to stack heavy shipping containers.
- Rail Intermodal: Facilities connecting rail and truck transport, often paved with RCC for speed and durability.
- Public Sector: Government-funded projects like state highways and municipal roads where Rollcon operates.
Technical Benefits & Performance
- High Early Strength: A characteristic of Rollcon’s RCC, typically attaining structural capacity in only 24–72 hours.
- Lifecycle Cost: The total cost of ownership; RCC has a lower lifecycle cost than asphalt due to durability and low maintenance.
- Frost Durability: The ability of RCC to withstand freeze-thaw cycles, a topic of specific research and reporting by Rollcon.
- Deicer Salt-Scale Resistance: The capacity of the pavement to resist surface damage from salt used to melt ice.
- Non-Air Entrainment: A characteristic of standard RCC mixes which, despite lacking entrained air, have shown resistance to frost in field performance.
- Spherical Air Bubbles: Small air voids (approx. 1.5%) that can beneficially influence the frost durability of RCC.
- Hydraulic Fluid Resistance: RCC’s ability to remain undamaged by oil or hydraulic fluid spills, unlike asphalt.
- Rutting Resistance: RCC’s rigidity prevents the formation of ruts or wheel path depressions common in flexible pavements.
- Shoving and Pushing: Resistance to surface displacement caused by heavy vehicle breaking and turning.
- High Temperature Resistance: RCC will not soften or deform under extreme heat, maintaining structural integrity.
- Accelerated Pavement Testing (APT): A testing method used by DOTs (e.g., Louisiana) to simulate years of traffic wear in a short period on Rollcon test sections.
Construction & Material Specifics
- Local Aggregates: Utilizing on-site or nearby materials for RCC to reduce costs and environmental impact.
- Compacted Mixture: The dense state of aggregate, cement, and water that forms the pavement structure.
- Bituminous Layer: An asphalt surface layer that can be placed on top of Roller Compacted (RCC) to complete the pavement structure.
- Elevation Tolerance: The precision of grading typically within 1/8th of an inch for CTB projects.
- Yield Tolerance: A measure of material usage efficiency; Rollcon notes a one-percent yield tolerance on major highway projects.
- No Forms: A major construction advantage of RCC, eliminating the labor and material cost of setting forms.
- No Reinforcement: RCC pavements typically do not require steel rebar or dowels, saving cost and installation time.
- Fast Construction: A primary benefit cited, with projects capable of 70% faster turnaround than conventional methods.
- Next-Day Traffic: The ability to open RCC pavements to traffic typically within 24 hours of placement.
- Safety Protocol: A critical operational focus, with clients citing zero incidents on massive material replacement projects.
- Resiliency: The capacity of concrete pavement to recover from and withstand environmental disasters.Sustainability: RCC contributes to economic and environmental goals through reduced material use and long lifespan.
- Maintenance Costs: Described as “minimal” over the life of an RCC pavement.
- Integrated Team: Rollcon’s internal workforce approach, avoiding outsourcing to ensure quality and safety.
- National Presence: Rollcon executes projects across the United States, not limited to a single region.
- Consultation: Free project assessments offered by Rollcon to determine if RCC is the right fit for a client’s needs
General Terminology
- Approval: Written authorization or acceptance from the Engineer prior to starting an activity.
- Construction Stakes: Markers positioned by the Engineer to establish lines and grades for street work and structures.
- Contractor: The construction firm or subcontractor hired to perform work under the contract specifications and drawings.
- Design Strength: The compressive strength used by the designer in the thickness design method to determine the RCC plan thickness.
- Engineer: The owner or agent of the owner who administers the work under contract specifications and drawings.
- Intent of the Contract: The requirement for the contractor to build pavement in reasonably close conformity with the lines, grades, and thickness shown in the plans.
- Lot: A specific volume or area of pavement placed in one day, or with one mixture, used for acceptance testing.
- Plan Thickness: The nominal pavement layer thickness shown in the project plans.
- Prequalification: The submission of evidence regarding successful prior installation of RCC pavement and proposed equipment.
- Quality Management Plan (QMP): A required document typically submitted 30 days prior to paving that outlines organization, schedule, equipment, and procedures.
- Required Average Strength: The average strength used in mixture proportioning to ensure the concrete meets acceptance criteria.
- Specified Compressive Strength: The strength used in design, typically 4,000 psi (non-freeze-thaw) or 4,500 psi (freeze-thaw) at 28 days.
- Sublot: The volume, area, or lineal quantity requiring a sample test for acceptance.
- Testing Laboratory: An organization that performs tests to determine characteristics or performance of materials, meeting ASTM C1077 requirements.
- Testing Technician: An engineer, technician, or experienced craftsman qualified to perform tests.
- The Plans: Drawings and details describing the dimensions, elevations, and locations of the pavement and infrastructure.
Material Specifications & Physics
- Aggregates: A blend of fine and coarse fractions used in RCC mixtures.
- Chemical Admixtures: Materials added to the mix to alter properties, such as retarders or hydration stabilizers.
- Coarse Aggregate: Aggregate conforming to AASHTO M80 or ASTM C33 standards.
- Combined Aggregate Gradation: The particle size distribution of the blended aggregate and sand, which must conform to specific sieve size ranges.
- Fine Aggregate: Aggregate conforming to AASHTO M6 or ASTM C33 standards.
- Fly Ash: A supplementary cementitious material; replacement is limited to 25% of Portland cement.
- Ground Granulated Blast Furnace Slag (GGBFS): A supplementary material that may replace up to 50% of Portland cement.
- Hydration Stabilizer: An admixture used to facilitate delivery logistics or keep joints fresh.
- Maximum Wet Density (MWD): The maximum unit weight of a dry RCC mixture at optimum moisture, determined per ASTM D1557.
- Moisture Content: The amount of water in the RCC mixture, typically must be within ±1.0% of the optimum.
- Optimum Moisture Content (OMC): The water content at which maximum wet density is achieved for a specific compaction effort.
- Plasticity Index: A measure of plasticity; aggregates for RCC must not exceed a PI of five.
- Portland Cement: Hydraulic cement conforming to AASHTO M85 or ASTM C150.
- Reference Wet Density (RWD): The calculation of MDD multiplied by , used as the baseline for density acceptance.
- Shelf Life: The manufacturer’s recommended storage duration for materials; expired materials are prohibited.
- Silica Fume: A supplementary cementitious material conforming to ASTM C1240.
- Supplementary Cementitious Materials (SCMs): Mineral admixtures (fly ash, slag, etc.) added to concrete to improve plastic or hardened properties.
Equipment & Machinery
- Central Mix Batch Plant: A Tilt Drum Rotary or Horizontal Shaft Mixer capable of producing homogeneous mixtures per ASTM C94.
- Dual Steel Drum Roller: Self-propelled compaction equipment used for primary and final compaction.
- Dump Trucks: Vehicles used for transporting RCC, which must be dumped clean with no buildup in corners.
- Early Entry Saws: Concrete saws capable of cutting new RCC for crack control with minimal raveling.
- Edge Shoe: A device attached to the paver to produce a compacted vertical cold joint face.
- High-Density Screed: A paver component equipped with tampers or pressure bars to achieve 90% density before rolling.
- Material Transfer Device: Equipment used to feed the paver from an offset position, required for high-speed projects or dual lift construction.
- Paving Machine: Equipment of suitable weight and stability to spread and compact RCC to required thickness and texture.
- Pneumatic Roller: Rubber-tire rollers used for compaction efforts alongside steel drum rollers.
- Pugmill Plant: A central plant type with a twin-shaft pugmill mixer capable of continuous mixing.
- Retractable Protective Covers: Covers for haul trucks to protect RCC from rain, evaporation, or heat during transport.
- Spray Bar: A device on a water truck capable of evenly applying a fine mist to the RCC surface.
- Surge Hopper: A hopper attached to the discharge belt of a pugmill to minimize segregation during truck loading.
- Synchronized Metering Devices: Plant components that dispense correct proportions of aggregate and cement for continuous mixing.
- Tamper Bar: A compaction device located within the high-density screed of the paver.
- Timing Device: A device on batch mixers that indicates mixing time after all materials enter the mixer.
- Water Truck: Site equipment used to keep the subgrade, subbase, and finished RCC moist.
Construction Procedures & Methods
- Adjacent Lane Placement: Placing a paving lane next to a fresh lane, ideally within 30 minutes.
- Cold Horizontal Joint: An interface between lifts where the bottom lift has dried or delayed >45 minutes; requires cleaning.
- Cold Joint Preparation: Cleaning loose material and wetting the joint face before placing new RCC.
- Cold Vertical Joint: A longitudinal joint where the adjacent lane is not placed within 60 minutes.
- Cold Weather Placement: Paving operations when temperatures fall below 40°F (C).
- Compaction Timing: The requirement to complete all compaction within 60 minutes of mixing.
- Curing: Keeping the RCC surface continuously moist for at least 5 days or using a curing compound.
- Dual Lift Construction: Placing RCC in two layers, often requiring synchronization or retarding admixtures.
- Expansion Joints: Joints installed to accommodate thermal effects, based on regional climatic conditions.
- Fresh Horizontal Joint: A bond between lifts where the top lift is placed within 45 minutes of the bottom lift.
- Fresh Vertical Joint: A longitudinal joint where the adjacent lane is placed within 30 minutes.
- Hand Spreading: Manual distribution of RCC, generally prohibited except for small repairs behind the paver.
- Haul Time: The time limit for transporting RCC from plant to paver, typically maximum 30 minutes.
- Hot Weather Precautions: Measures taken when temperatures exceed 90°F (C), such as cooling aggregates.
- Isolation Joints: Joints lining fixed structures like manholes to separate them from the pavement.
- Joint Sealing: Installing sealants in prepared joints if required by project documents.
- Lift Thickness: Single lift thickness is achievable between 4 inches and 10 inches; greater thicknesses require Engineer approval.
- Mixing Time: The duration materials must remain in the mixer to ensure thorough blending.
- Multiple Lift Placement: Compacting a bottom lift to density before placing the top lift, usually within 45 minutes.
- Plant Calibration: A comprehensive check of scales and metering devices prior to production.
- Proof Rolling: Checking the subgrade for soft areas using a loaded 50,000 lb dump truck prior to paving.
- Sawing: Cutting crack control joints to 1/4 depth of the lift thickness.
- Static Mode: Operating a steel drum roller without vibration, required for final compaction.
- Subbase Fine Grading: Grading the subbase to a tolerance of +0, -1/2 inch prior to RCC placement.
- Test Section: A 100-ft trial pavement constructed 3-7 days before starting work to validate mix and equipment.
- Troweling: A finishing technique used to improve the aesthetic appearance of the RCC surface.
Quality Control & Acceptance
- Compressive Strength Test: Determining strength via cylinders (ASTM C1435/C39) or cores (ASTM C42).
- Core Visual Inspection: Examining extracted cores for honeycombing or segregation at the bottom of the lift.
- Corrective Grinding: Using a grinding device to fix smoothness deficiencies.
- Deficient Thickness: Pavement thickness that is more than 0.5 inch less than the plan thickness.
- Diamond Grinding: A method to improve smoothness or texture of the exposed RCC surface.
- In-Place Wet Mat Density: Density measured directly behind the paver and after compaction using a nuclear gauge.
- Joint Density: Density measured at the joint, which must be at least 96% of the reference wet density.
- Price Adjustment Factor: A reduction in payment applied to pavement with deficient thickness or strength.
- Raveling: The dislodging of aggregate at saw-cut edges; must not exceed 3/8″ wide.
- Removal and Replacement: The required remedy for areas with strength <74% of design or thickness deficiency >0.5 inch.
- Segregation: The separation of coarse and fine aggregates, which must be minimized during loading and paving.
- Smoothness Tolerance: Surface variance not exceeding 0.375 inch under a 10-foot straightedge.
- Surface Texture: The final finish, which should be uniform and free of tears greater than 1/4″ depth/width.
- Thickness Verification: Determining pavement depth using cores or approved non-destructive devices.
Reference Standards (ASTM/AASHTO/CSA)
- AASHTO M6: Standard Specification for Fine Aggregate for Portland Cement Concrete.
- AASHTO M80: Standard Specification for Coarse Aggregate for Hydraulic Cement Concrete.
- AASHTO M85: Standard Specification for Portland Cement.
- AASHTO M148: Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete.
- AASHTO M194: Standard Specification for Chemical Admixtures for Concrete.
- AASHTO M240: Standard Specification for Blended Hydraulic Cement.
- AASHTO M295: Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan.
- AASHTO M302: Standard Specification for Slag Cement for Use in Concrete and Mortars.
- AASHTO T26: Standard Method of Test for Quality of Water to Be Used in Concrete.
- AASHTO T99: Test for Moisture-Density Relations of Soils Using a 2.5-kg Rammer.
- AASHTO T180: Test for Moisture-Density Relations of Soils Using a 4.54-kg Rammer.
- ACI 214: Evaluation of Strength Test Results of Concrete.
- ASTM C31: Practice for Making and Curing Concrete Test Specimens in the Field.
- ASTM C33: Standard Specification for Concrete Aggregates.
- ASTM C39: Test Method for Compressive Strength of Cylindrical Concrete Specimens.
- ASTM C42: Test Method for Obtaining and Testing Drilled Cores and Sawed Beams.
- ASTM C78: Test Method for Flexural Strength of Concrete (Simple Beam with 3rd Point Loading).
- ASTM C94: Standard Specification for Ready-Mixed Concrete.
- ASTM C150: Standard Specification for Portland Cement.
- ASTM C171: Standard Specification for Sheet Materials for Curing Concrete.
- ASTM C174: Standard Test Method for Measuring Thickness of Concrete Elements Using Drilled Concrete Cores.
- ASTM C309: Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete.
- ASTM C494: Standard Specification for Chemical Admixtures for Concrete.
- ASTM C496: Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens.
- ASTM C566: Test Method for Total Evaporable Moisture Content of Aggregate by Drying.
- ASTM C595: Standard Specification for Blended Hydraulic Cements.
- ASTM C618: Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan.
- ASTM C685: Standard Specification for Concrete Made by Volumetric Batching and Continuous Mixing.
- ASTM C989: Standard Specification for Slag Cement for Use in Concrete and Mortars.
- ASTM C1040: Test Method for Density of Concrete in Place by Nuclear Methods.
- ASTM C1077: Standard Practice for Agencies Testing Concrete and Concrete Aggregates.
- ASTM C1157: Standard Performance Specification for Hydraulic Cement.
- ASTM C1170: Test Method for Determining Consistency and Density of RCC Using a Vibrating Table.
- ASTM C1176: Practice for Making RCC in Cylinder Molds Using a Vibrating Table.
- ASTM C1240: Standard Specification for Silica Fume Used in Cementitious Mixtures.
- ASTM C1262: A test method cited by Rollcon as reliable for assessing the frost durability of RCC.
- ASTM C1435: Practice for Molding RCC in Cylinder Molds Using a Vibrating Hammer.
- ASTM C1602: Standard Specification for Mixing Water Used in the Production of Hydraulic Cement Concrete.
- ASTM D698: Test for Moisture-Density Relations of Soils Using a 2.5-kg Rammer.
- ASTM D977: Standard Specification for Emulsified Asphalt.
- ASTM D1557: Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort.
- ASTM E329: Standards of Recommended Practice for Inspection and Testing Agencies.
- CSA A23.1/A23.2: Concrete Materials and Methods of Concrete Construction/Test Methods.
- CSA A3001: Cementitious Materials for Use in Concrete.
