Technical Info





GENERAL PROVISIONS

100. SCOPE OF WORK

The work to be completed under this contract includes the furnishing of all labor, materials and equipment necessary for the construction of the proposed improvements in conformance with the plans and specifications.

101. References:

A. American Society of Testing and Materials

1. ASTM C 29, Test for Unit Weight and Voids in Aggregate.
2. ASTM C 33, Specifications for Concrete Aggregates
3. ASTM C 39, Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
4. ASTM C 42, Text methods for Obtaining and Testing Drilled Cores and Sawed Beams of Concret
5. ASTM C 78, Standard Text Method for Flexural of Concrete (Using Simple Beam with Third-Point Loading
6. ASTM C 140, Methods of Sampling and Testing Concrete Masonry Unit
7. ASTM C 150, Specifications for Portland Cement (Type I or II only
8. ASTM C 172, Practice of Sampling Fresh Concrete
9. ASTM C 494, Specifications for Chemicals Admixtures for Concrete
10. ASTM C 618, Specification for Coal Fly Ash and Raw or Calcimined Natural Pozzolan for Use as a Mineral Admixture in Portland Cement Concrete
11. ASTM C 944, Standard Test Method for Abrasion Resistance of Concrete or Mortar Surfaces by the Rotating Cutter Method
12. ASTM C 989, Specifications for Ground Granulated Blast Furnace Slag for One in Concrete and Mortars
13. ASTM E 329, Standard Recommended Practice for Inspection and Testing Agencies for Concrete, Steel, and Bituminous Materials as Used in Construction
14. ASTM C 1077, Practice for Laboratories Testing Concrete and Concrete Aggregates for Use in Construction and Criteria for Laboratory Evaluation
15. ASTM C 448, Specification for Standard Sizes of Coarse Aggregates for Highway Construction
102. Contractor Qualifications:

The use of a NRMCA Certified Pervious Concrete Installer is required. Prior to award of the contract, the placing contractor shall furnish owner/engineer/architect a statement attesting to qualifications, experience, and the following:

1. A minimum of five completed projects with addresses
2. Unit weight acceptance data
3. Pavement test results including void content and unit weight
4. Sample of product (i.e. core or test panel)

If the placing contractor and concrete producer do not have sufficient experience with Pervious Pavement, the placing contractor shall retain an experienced consultant to monitor production, handling, and placement operations at the contractor's expense.

200. MATERIALS:

201. General:

Locally available materials having a record of satisfactory performance shall be used.

202. Cement:

Use Portland Cement Type I or Type II conforming to ASTM C 150.

203. Fly Ash:

Use Type F fly ash conforming to ASTM C 618.

204. Aggregate:

Use Federal DOT No. 89 coarse aggregate (3/8 to No. 50) per ASTM D448. If other gradation of aggregate is to be used, submit data on proposed material to Stoney Creek Materials, L.L.C. for approval.

205. Air Entraining Agent:

Not applicable.

206. Admixture:

Use Degussa or equal Admixture

207. Water:

Use potable water or water that complies with Federal DOT Standard Specifications.

208. Curing Agents:

Use curing agents that are non-yellowing, non-reacting to cementitious materials.

209. Non-woven Geo-textile Filter Fabric:

Use a non-woven polypropylene geo-textile filter fabric. Fabric should be inert to biological degradation and resistant to chemicals, alkali and acid. (Like that of Mirafiâ 140N filter material)

300. PROPORTIONS:

301. Concrete Mix Design:

Contractor shall furnish to the concrete "batch plant" a proposed mix design that includes proportions of materials.

Standard Design Mix*

2700
Lbs.
3/8” clean aggregate
564 Lbs. Type I Portland Cement including 20% “Type F” Fly Ash
24 Gals. Municipal water
2.5 Gals. Admixture

*This is the standard or typical design mix. Specific design mixes are available for unique applications. Contact your certified contractor.

302. Cement Content:

For pavements subject to vehicular traffic loading, the total cementitious material shall not be less than 564 lbs. per cubic yard, with a recommended 80% being Type l Portland and 20% being “Type F” Fly Ash.

303. Aggregate Content:

The volume of aggregate per cubic yard shall be equal to 27 cubic feet when calculated as a function of the unit weight determined in accordance with ASTM C 29 jigging procedure.

304. Admixture Content

Admixture shall be 2.5 gallons per yard of concrete.

305. Mix Water Content:

Mix water quantity shall be a minimum of 24 gallons per yard of concrete such that the cement paste displays a wet metallic sheen without causing the paste to flow from the aggregate. (Mix water quantity yielding a cement paste with dull-dry appearance has insufficient water for hydration).

400. SUB-GRADE PREPARATION, FORMS:

401. Sub-grade permeability:

Prior to placement of pervious pavement, the sub-grade shall be tested for rate of permeability by a suitable test of sub-grade soil permeability. The tested permeability must reasonably compare to the design permeability. A rate of 1/10th of an inch per hour can be used as a minimum percolation rate if this meets local water quality sedimentation/filtration/detention regulations.

402. Sub-grade Support:

Scarify sub-grade organic material (3" min) and proof roll to identify and eliminate any soft, wet, or puddle areas. Permeability of the sub-grade must be maintained. A geo-technical study must be performed to establish suitable soil stability. If fill material (embankment) is required to bring the sub-grade to final elevation, the fill material shall be clean and free of deleterious materials per geo-technical study. Do not over compact the fill material.

403. Sub-grade Moisture:

The sub-grade shall be in a moist condition (within +/- 3%) of the optimum moisture content as determined by the modified compaction test ASTM D 1557.

404. Filter Fabric Installation:

Placement of the non-woven geo-textile filter fabric should be continuous throughout the entire storage area. This includes both the bottom and the walls to the finish grade of the storage pond. Seams should be overlapped a minimum of 12”.

405. Aggregate/Water Storage Material:

The depth of crushed rock shall be determined by an engineering study for storm water storage. The material shall be (but not limited to) aggregate 100% retained on 1 ½ inch sieve, 100% passing a 2-inch sieve with no fines (e.g. washed river bed rock or crushed stone) per geo-technical study. Once in place, the aggregate shall be compacted in a single pass using a plate or roller compactor to provide uniform flat surface. Any truck ruts or other irregularities in the sub-grade must be smoothed prior to placing the concrete. Immediately prior to concrete placement, the aggregate shall be saturated with water in order to minimize pulling moisture from freshly poured concrete.

406. Forms:

Forms may be made of wood or steel and shall be the depth of the pavement. Forms shall be of sufficient strength and stability to support mechanical equipment following spreading, strike-off and compaction operations without deformation of plan profiles.

500. MIXING, HAULING, DISCHARGE, PLACING, JOINTING, CURING:

501. Transportation:

The cement/aggregate mixture may be transported to the site or mixed on the site.

502. Delivery:

At delivery, each mixer truck will be inspected for appearance of concrete uniformity according to Section 305. A slump test shall be performed prior to the introduction of the Admixture. A slump of 4” to 6” is recommended at this time. Water may be added to obtain the required mix consistency without causing the paste to flow from the aggregate.

503. Mix Time:

A minimum of 75 revolutions or 10 minutes (whichever is longer) at high mix speed shall be required following the addition of Admixture to the cement/aggregate mix.

504. Discharge:

Discharge shall be a continuous operation and shall be completed as quickly as possible. Concrete shall be deposited as close to its final position as practical. The fresh concrete must enter the mass of previously placed concrete. The practice of discharging onto sub-grade and pulling or shoveling to final placement is not allowed.

505. Jointing:

Transverse control (contraction) joints may be installed at 20-foot intervals. They shall be installed at a depth of ¼” to 3/8” in the pavement. Longitudinal control joints may be installed at the midpoint of the constructed lane width that exceeds 15 feet. These joints can be installed in the wet concrete (no saw cut). The procedure should begin as soon as the pavement has been laid to prevent raveling and uncontrolled cracking (normally after curing). Transverse construction joints shall be installed whenever placing is suspended a sufficient length of time that concrete may begin to harden. In order to assure an aggregate bond at construction joints, existing concrete pavement surface edge must be finished on a vertical (cold joint). Isolation (expansion) joints will not be used except when pavement is abutting slabs or other adjoining structures.

506. Placing and Finishing Equipment:

The contractor shall provide mechanical equipment of either Rolling screed, slip form, vibrating screed, laser screed, or comparable finishing apparatus including but not limited to an asphalt/concrete lay down device that will provide a minimum of 10 psi vertical force. The pervious concrete pavement will be placed to the required cross section and shall not deviate more than + 3/8 inch in 10 feet from profile grade. Surface-only applied vibration, if used, shall be shut off immediately when forward progress is halted for any reason.

If hand installation is necessary, a compaction device that provides sufficient compactive effort shall be used immediately following the strike-off operation. After mechanical or other approved strike-off compaction operation, no other finishing operation will be allowed.

The contractor will be restricted to pavement placement widths of a maximum of eighteen (18) feet unless the contractor can demonstrate to the satisfaction of the consulting engineer the competence to provide pavement placement widths greater than the maximum specified.

507. Curing and Curing Agents:

Curing procedures should begin within 20 minutes after placement. It is recommended that a curing agent be use on all placements. Follow manufactures instructions. An even application should be applied after edging and finishing as a continuous process to the placement of the pervious concrete. Such applications should happen within the first 20 minutes of placement. A second application may be applied, as soon as the first coat has dried. This sheen coat may be provided to the customer for a more aesthetic finish. Unless extreme weather conditions are present, NO covering is necessary.

After the recommended curing agent has dried to a non-tacky surface, it is recommended in extreme weather conditions (such as >90ºF or <40ºF or windy conditions), to cover the pervious pavement surface with a minimum of six (6) mils thick polyethylene sheet or other approved covering material. The cover shall overlap all exposed edges of the pervious pavement and shall be secured (without using dirt or stone) to prevent dislocation due to winds or adjacent traffic conditions. It is recommended that this covering stay in place for a minimum of 72 hours.

600. TESTING, INSPECTION, ACCEPTANCE:

601. Laboratory Testing:

The owner will retain an independent testing laboratory. The testing laboratory shall conform to the requirements of ASTM E 329 and ASTM C 1077 and shall be inspected and accredited by a recognized national authority.

The agent of the testing laboratory performing field sampling and testing for concrete shall be certified by the American Concrete Institute as a Concrete Field Testing Technician Grade I, or by a recognized state or national authority as an equivalent level of competence.

602. Inspection and Acceptance:

A minimum of one gradation test of the storage aggregate is required to determine percent passing of the No. 200 sieve per ASTM C 117.

A minimum of one test for each day's placement of pervious concrete shall be conducted in accordance with ASTM C 172 AND ASTM C 29 to verify unit weight. Delivered unit weights are to be determined in accordance with ASTM C 29 using a 1.25 cubic foot cylindrical metal measure. The measure is to be filled and compacted in accordance with ASTM C 29 Paragraph 11, jigging procedure. The unit weight of the delivered concrete shall be +/-five (5) percent of design weight.

Test panels shall have two cores taken from each panel in accordance with ASTM C 42 at a minimum of seven (7) days after the placement of the pervious concrete. The cores shall be measured for thickness, void surfaces, and unit weight. Untrimmed, hardened core samples shall be used to determine placement thickness. The average of all production cores shall not be less than the specified thickness with no individual core being more than 1/2 inch less than the specified thickness. After thickness is determined, the cores shall be trimmed and measured for unit weight in the saturated condition as described in paragraph 6.3.1 "Saturation" of ASTM C 140. The trimmed cores shall be immersed in water for 24 hours, allowed to drain for one (1) minute, the surface water removed with a damp cloth, and then weighed immediately. Ranges of satisfactory unit weight values are +/- five (5) percent of the design unit weight.

After a minimum of seven (7) days following each placement, three cores shall be taken in accordance with ASTM C 42. The core shall be measured for thickness and unit weight determined as described above for test panels. Core holes shall be filled with concrete meeting the pervious pavement mix design.

700. MAINTENANCE, CLOGGING, PREVENTION, SPECIAL RECOMMENDATIONS

701. Maintenance:

The finished and cured Pervious Pavement requires specific maintenance in order to maintain its pervious nature. It is recommended as a minimum (but not limited to) that the surface be vacuumed 4 times per year, on three-month intervals, in order to lift any silt or debris from the surface. This process will avert clogging of the pervious system. It may be necessary to increase the frequency of vacuuming should over-hanging vegetation, excessive dirt, and pollutants foul the pervious pavement surface.

Power washing is also recommended at a minimum of a semi-annual basis in order to flush silt or other contaminants from the pervious pavement. This is essential to maintaining the permeability of the pervious system. It has been determined that these fines cause little to no threat to the system when washed into the lower and larger aggregate.

702. Clogging and Prevention

It has been determined that the largest threat to clogging the system occurs during two basic times in the life of the system.

The foremost time is during the initial and/or re-modeling stages of construction, when contractors use the pervious pavement areas to store materials such as sand, gravel with fines, dirt, and/or landscape materials containing fines. These contaminants will clog the pervious pavement surface. Ownership must assume the responsibility of notifying these contractors to their responsibility to keep the pervious pavement areas protected. Examples of protection methods include (but are not limited to) using heavy Visqueen and/or plywood under such piles and covering all piles to prevent blowing and/or washing away of such materials due to weather conditions.

The second most recognized threat to the permeability of the pervious system is the near proximity of landscape ground covers such as mulch, dirt, or other organic materials containing large amounts of buoyant fines which might float during heavy rain showers or from poorly constructed or poorly maintained sprinkling devices. These organic fines will clog the pervious pavement.

It is recommended that such areas be designed to achieve two separate yet distinct goals. Firstly, prevent washing and floating of materials over or through the pervious system by grading or slumping drainage away from the pervious system. Secondly, prevent larger fines from lodging in the system voids by adding a filter material such as (but not limited to) sod to the vertical surface of the pervious pavement closest to the landscape areas. A combination of grade slumping and filter material is strongly recommended.

Note: The installation contractor cannot assume nor will assume any responsibility for the ongoing maintenance of the pervious system.

703. Special Recommendations:

703.1 Clean-up of hydrocarbons, oil spills, oil drips:
Many are concerned with the possibility of hydrocarbons leaching into the soil below the pervious pavement system. Fortunately, naturally occurring microorganisms will aerobically break down and rid the soil of these hydrocarbons. Average soils possess these microorganisms.

The secret in breaking down hydrocarbons is the availability of oxygen and nutrients that promote the healthy growth of the microbes. We recommend the use of a Nutrient Supplement product to assist in the breakdown of the hydrocarbons.

For standard parking lots, apply annual dosages of the Nutrient Supplement. The product will need to be “watered in” and made available to the oil for degradation. If applications are in heavy industrial locations, a “pre-installation” application is recommended. This will keep the nutrients available immediately for anticipated need.

For emergency spills, no excavation is necessary when an emergency heavy dosage is available within 24 hours of the spill. With this “Spill” dosage, the microbes will degrade the hydrocarbons to eventually dispose of the pollutants.

703.2 Organic Material Build-up, Clogging, and Clean-up:

When organic materials (leaves and landscape materials) clog the surface of the pervious pavement, it is recommended to use a sludge busting microbiological material. This material should be applied during the leaf drop or when organic materials are dumped and clog the surface.

The Sludge busting organics should be watered in (a minimum of 1/2") and maintain a moist environment for a minimum of 30 days. This allows the breakdown to fully take place and restores complete permeability. Applying this during leaf drop will normally be at a time of natural moisture.

703.3 Signage:

It is strongly recommended/encouraged that signage is posted in landscaped areas and at entrances to the property as reminders of the ecologically sensitive pavement structure and that certain guidelines must be adhered to including (but no limited to):

1. No piling of dirt, sand, gravel or landscape material without covering the pavement first with durable cover in order to protect the integrity of the pervious surface.

2. All landscape cover must be graded to prevent the washing and/or floating of materials onto or through the pervious surface

3. All chemical spills (inclusive but not limited to petrocarbons) should be reported to the property owners so they might determine proper flushing and/or the usage of microbiological material in order to neutralize any or all impact on the under soil/water ecological system.

These are some but may not be all areas of concern that owners of such properties should post signage to protect and prevent contamination of the pervious ecological system.