SUDAS Revision Submittal Form

SUDAS Revision Submittal Form Status Date: As of 3/13/15 Topic: Permeable interlocking pavers Manual: Design & Specs Manual Location: Design Section 5L-1; Spec Section 7080 Requested Revision: Reason for Revision: Comments: See attached additions. Developed new sections to include in both manuals. None. District: 1 2 3 4 5 6 Initial Comments: None. Final Comments: None. Action: Deferred Not Approved Approved District: 1 2 3 4 5 6 Initial Comments: None. Final Comments: None. Action: Deferred Not Approved Approved District: 1 2 3 4 5 6 Initial Comments: Clarify the second paragraph on page 1 of the Design section ("Permeable pavements can dramatically reduce the surface runoff from most rainfall events"). Note - added "disconnecting and distributing runoff through filtration and detention" to the end of the sentence. Final Comments: Delete "concrete" (when referencing the pavers) throughout the figures. Note - done. Action: Deferred Not Approved Approved District: 1 2 3 4 5 6 Initial Comments: Page 2 of the Design section states that the operating speed of the facility should be below 45 mph; should that be 35 mph? What about clay pavers? In Spec Section 7080, 1.07, delete the surcharge language. Note - the speed was changed to 35 mph, clay pavers were added, and the surcharge language was deleted. Final Comments: None. Action: Deferred Not Approved Approved District: 1 2 3 4 5 6 Initial Comments: Are there prequalification requirements? Show a detail of the curb and gutter section with intakes. Extend the aggregates under the curb and gutter section, similar to Figure 7080.102. Note - prequalification requirements were added and the figures were modified. Final Comments: PCC collar brings storm sewer collars to mind. Suggested using "PCC edge restraint" or "PCC band." Note - changed to PCC edge restraint. Action: Deferred Not Approved Approved

District: 1 2 3 4 5 6 Initial Comments: None. Final Comments: In 1.08, F, 3 it says "refilling joint material after 6 months." Suggested deleting "material" because it makes it sound like the contractor just has to provide the material and maybe not doing the work. Note - done. Action: Deferred Not Approved Approved Final District Action Summary: All 6 districts approved; see comments above. Board of Directors Action:

DRAFT Design Manual Chapter 5 - Roadway Design 5L - Permeable Interlocking Pavers 5L-1 Permeable Interlocking Pavers A. General Permeable pavements are designed to infiltrate runoff, whereas runoff sheds off the surface of conventional pavements. In permeable pavements, runoff passes through the surface and is stored in the aggregate base. In pervious soils, the runoff infiltrates the soil; in less permeable soils, a subdrain system is placed to slowly discharge the runoff. Runoff volume reduction is achieved as the water is infiltrated into the underlying soils. Peak runoff rate reduction is realized due to the stormwater being stored in the aggregate subbase and slowly released to the downstream piping systems. Traditionally, at a minimum, the depth of the aggregate subbase is designed to meet the storage needs for the Water Quality Volume (WQv), which is 1.25 inches of rainfall in Iowa. Permeable pavements can dramatically reduce the surface runoff from most rainfall events by disconnecting and distributing runoff through filtration and detention. The use of permeable pavements can result in stormwater runoff conditions that approximate the predevelopment site conditions for the immediate area covered by the pavers. The design of permeable interlocking pavements (PIP) involves both structural and hydrological analyses. Figure 5L-1.01 illustrates a typical cross-section of a PIP. These two design elements are typically not interconnected and in reality are often in conflict. This is particularly the case with the subgrade treatment and volume of aggregate subbase. Structural design requires a compacted subgrade and the hydrologic design desires an uncompacted subgrade to allow as much infiltration as possible. In most instances, the hydrologic requirements for filter and storage aggregate exceed the structural needs for the unbound aggregate subbase. Figure 5L-1.01: Permeable Interlocking Paver Cross-section 1 DRAFT

Chapter 5 - Roadway Design 5L-1 - Permeable Interlocking Pavers PIP are used for low speed/low volume streets, alleys, parking lots, and driveways. The design and operating speed of the facility should be below 35 mph. Permeable paver projects should only be developed in areas dominated by impermeable surfaces or surfaces that are fully vegetated so that sediment runoff is minimized and life of the pavement is maximized. PIP are capable of handling truck traffic. The following elements should be reviewed prior to undertaking a detailed design process: Underlying geology and soils NRCS hydrologic soils groups History of fill, disturbance, or compaction of underlying soils Current drainage patterns and volume of runoff Local and downstream drainage facilities Distances to potable water supply wells Elevation of the static water table Traffic volumes, including percent trucks Because water is stored in the subbase rock, it may be necessary to protect structures that are adjacent to the permeable paver project by sealing the foundation walls. The PIP must be a minimum of 100 feet from a municipal water supply well. There are two types of permeable interlocking pavers. One type is concrete pavers that are 3 1/8 inches thick; the other type is clay brick pavers that are at least 2 5/8 inches thick. The concrete pavers must comply with ASTM C 936. There are two ASTM standards for brick pavers, depending on the traffic loading. ASTM C 902 is for pedestrian and light vehicular traffic locations. ASTM C 1272 is for heavier vehicular traffic and will be the type listed in the SUDAS Specifications. The clay pavers should be 2 3/4 inches thick, Type F brick for PX applications according to ASTM C 1272. B. Structural Design The design procedure for permeable interlocking pavers is the same as for flexible pavements. Research has shown that the load distribution and failure modes of PIP are similar to other flexible pavements. Because the designs are the same as for flexible pavements, the AASHTO Guide for Design of Pavement Structures (AASHTO, 1993) can be used. The paver used in design for concrete pavers is a 3 1/8 inch thick paver with a minimum 1 inch bedding layer. The structural coefficient is 0.44 per inch. This provides a structural number of 1.82. The clay brick paver is 2 3/4 inches thick, which has a corresponding structural number of 1.21. The remaining structural support comes from the aggregate layers and the soil subgrade. The American Society of Civil Engineers has developed a design standard called Structural Design of Interlocking Concrete Pavement for Municipal Streets and Roadways (ASCE/T&DI/ICPI 58-10). The structural design for clay brick pavers is the same as for concrete pavers. The engineer will need to determine or select the following: Design traffic loading (ESALS) Design life (40 years minimum) Design reliability (usually 75% to 80%) Overall standard deviation (0.45) Required structural number to meet traffic loading Initial serviceability (flexible pavements = 4.2) Terminal serviceability (local streets = 2.0) Subgrade resilient modulus based on saturated soil characteristics, including seasonal variability 2 DRAFT

Chapter 5 - Roadway Design 5L-1 - Permeable Interlocking Pavers Drainage conditions Once these elements are determined, the design thickness of the unbound aggregate subbase can be determined. The ASCE design standard has tables showing thickness of the layers that were developed using the AASHTO 1993 Guide. Thickness is selected based on the ESALS, the soil category, and the drainage. Three types of interlock are critical to achieve: vertical, rotational, and horizontal. Vertical interlock is achieved by the shear transfer of loads to surrounding pavers through the material in the joints. Rotational interlock is maintained by the pavers being of sufficient thickness and aspect ratio (3:1 minimum), being placed close together, and restrained by a curb from lateral forces of vehicle tires. Rotational interlock can be further enhanced if there is a slight crown to the pavement cross-section. Horizontal interlock is primarily achieved through the use of laying patterns that disperse forces from braking, turning, and accelerating vehicles. Herringbone patterns, either 45 or 90, are the most effective patterns for maintaining interlock. A string or soldier course should be used at the interface between the pavers and the edge restraint. A PCC edge restraint is typically used for street and alley projects. The edge restraint may be a standard curb and gutter section, a vertical curb section, or a narrow concrete slab, and should be placed on the subbase aggregates. After placement, the pavers are compacted with a high frequency plate compactor, which forces the joint material into the joints and begins compaction of the paver into the bedding layer. The pavement is transformed from a loose collection of pavers into an interlocked system capable of spreading vertical loads horizontally through the shear forces in the joints. One of the direct conflicts with the hydrologic design of PIP is the compaction of the subgrade soils. The structural design calls for subgrades compacted to 95% Modified Proctor Density according to AASHTO T 180. The effective compaction depth should be 12 inches minimum. This compaction requirement will prevent efficient infiltration of water through the subgrade and thus will likely necessitate a piping design to handle the stormwater that accumulates in the storage aggregate (unbound subbase). The engineer should provide a geotextile between the subgrade and the storage aggregate (subbase) as a means of preventing mixing of the materials. The geotextile should comply with Iowa DOT Section 4196 for subsurface drainage. C. Hydrologic Design The design process follows traditional storm sewer procedures for pavements. The initial step in the hydrologic design is the determination of the design storm event. Some agencies may establish the storm return period and the rainfall intensity. Information on intensity-duration-frequency for various return periods can be found in Chapter 2. In addition, the contributing area must be determined. The runoff volume should be determined according to the methods described in Chapter 2 using a design rainfall depth of 1.25 inches as a minimum, unless the jurisdiction has a different policy. The next step involves establishing the drainage area. The storm event is then applied to the drainage area and the volume of runoff is determined. The permeability of the subgrade soil is a critical design element. If the subgrade soil permeability is less than 1/2 inch per hour, a subdrain piping network will be needed. Soil compaction to support vehicular traffic will decrease permeability. Good design practice for vehicular traffic loads is to provide a minimum CBR of 5. Thus as the soil permeability is determined it should be assessed at 3 DRAFT

Chapter 5 - Roadway Design 5L-1 - Permeable Interlocking Pavers the density required to realize a CBR of 5 under soaked conditions. To maximize the effectiveness of the PIP, the pavement grade should be as flat as possible, although steeper grades can be used. The general guideline is that the longitudinal grade should be greater than 1% and less than 12%. Three design alternatives exist for the PIP. They are: Full infiltration: All of the stormwater runoff from the design storm is infiltrated into the subgrade soils. See Figure 5L-1.02.A. Partial exfiltration: Some of the design storm runoff is infiltrated and the remainder is collected in the subdrain system and slowly discharged into the downstream systems. This is accomplished by setting the subdrain pipe above the top of the subgrade. See Figure 5L- 1.02.B. Full Exfiltration: Soil permeability is limited and thus all of the runoff volume is carried away through the subdrain piping. See Figure 5L-1.02.C. Designers must also evaluate and provide for larger storm events. One way to provide for the larger storms but still provide for infiltration of the water quality storms is to raise the elevation of the intakes above the pavers so the small storms are infiltrated and the large storms are handled by the intakes and pipe network. Once the volume of runoff and the soil permeability are known, the thickness of the storage aggregate layer (Iowa DOT Gradation No. 13/ASTM Gradation No. 2) can be determined. The void space (volume of voids/volume of aggregate) for Iowa DOT Gradation No. 13 is 40%. A 40% void space provides 0.4 cubic feet of stormwater storage for each cubic foot of aggregate. Thus, the volume of the storage aggregate will need to be 2.5 times the volume of water to be stored. Due to the need to compact the subgrade soil to handle vehicles, it is very likely that subdrains will be needed to discharge at least a portion of the runoff. The elevation and sizing of the subdrains should be set to provide for full discharge of the design storm within 72 hours either through infiltration into the subgrade soil or through subdrain pipe discharge. In order to prevent absorption of the bedding stone into the storage aggregate layer, a layer of filter aggregate (Iowa DOT Gradation No. 3/ ASTM Gradation No. 57) is needed. This layer is typically 4 inches thick. The bedding aggregate (Iowa DOT Gradation No. 29/ASTM Gradation No. 8) is then placed 2 inches thick, compacted, and leveled. Fine graded sand should not be used as the bedding and for filling of voids due to the increased clogging potential. The pavers are placed, additional bedding stone is added to fill the voids in between the pavers, the area is swept, and finally the pavers are compacted. Sweeping prior to compaction is important to prevent stones on the surface from marring or cracking the pavers. That process may need to be repeated to entirely fill the voids. The final step is to sweep and remove any excess void filler stone. 4 DRAFT

Chapter 5 - Roadway Design 5L-1 - Permeable Interlocking Pavers Figure 5L-1.02: Permeable Interlocking Paver Design Alternatives 5 DRAFT

Chapter 5 - Roadway Design 5L-1 - Permeable Interlocking Pavers D. Construction Elements Monitoring and controlling the construction activities of a permeable interlocking paver project are critical to the long-term performance of the permeable pavement. Preventing and diverting sediment from entering the aggregates and pavement during construction must be of the highest priority. Aggregate stockpiles must be isolated to prevent contamination by sediment. Erosion and sediment control devices must be placed and maintained throughout the project until vegetation is fully established. All unnecessary vehicle and pedestrian traffic should be restricted once the aggregate placement has initiated. It may be necessary to wash vehicle and equipment tires to prevent tracking dirt and mud onto the aggregate layers. A test section (approximately 5 feet by 5 feet) should be constructed to provide a basis for construction monitoring. The test section should be placed on the prepared subgrade to illustrate the processes used to place the pavers and illustrate the paver pattern and the edge details. Restrict all equipment and workers from the paver placement area once the bedding stone has been placed, leveled, and compacted. Pavers may be placed by hand or mechanically. Placement should proceed from one end or side and continue work from the completed placement areas. An important consideration with mechanically placed pavers for large projects it to ensure the wear on the paver molds does not change the size of the pavers and thus impact the ability to correctly place the pavers. E. Maintenance As with any pavement, particularly permeable pavements, specific maintenance activities are necessary to achieve the design life of the pavement. PIP can become clogged with sediment that affects its infiltration rate. The rate of sedimentation can depend on the number and type of vehicles using the pavement, as well as the control of erosive soils adjacent to the pavement. The most important element of maintenance is keeping the sediment out of the pavement by vacuum sweeping. Regular vacuum street sweeping will maintain a high infiltration rate and keep out vegetation. Calibration of the vacuum force may be necessary to remove the sediment but minimize removal of the filler material from the joints. Over time, it may be necessary to add additional joint filler material to prevent intrusion by sediment. Winter maintenance involves plowing snow and applications of de-icing chemicals. Although not required, snowplows can be equipped with rubber edged blades to minimize chipping of the pavers. Use of de-icing chemicals is often not necessary because the PIP remains warmer throughout the winter. Sand should not be used as an abrasive for traction. The sand will clog the filler material in the pavement joints. 6 DRAFT

DRAFT Division 7 - Streets and Related Work Section 7080 - Permeable Interlocking Pavers PERMEABLE INTERLOCKING PAVERS PART 1 - GENERAL 1.01 SECTION INCLUDES A. Subgrade Preparation B. Placement of Storage Aggregate C. Placement of Filter Aggregate D. Placement of Bedding Course E. Placement of Permeable Interlocking Pavers F. Quality Control G. Protection of the Pavement 1.02 DESCRIPTION OF WORK Construct permeable interlocking pavement for mitigation of stormwater runoff. 1.03 SUBMITTALS A. Sample Pavers: Representative of the type and color proposed for the project. B. Installation Instructions: Manufacturer s published installation instructions. C. Material Certification: Submit certification letter from paver manufacturer indicating compliance with the ASTM specifications and the contract documents. D. Bedding, Filter, and Storage Aggregates: Submit 5 pound samples of each aggregate type. Include aggregate type, source, gradation, and compacted void content. E. Project Details: Include schedule, construction procedures, and quality control plan that describes material staging; paving direction; details of placement and compaction of the storage, filter, and bedding aggregate; and the paver installation procedures. F. Involved Parties: Submit a list of all subcontractors, material suppliers, and testing laboratories. 1.04 SUBSTITUTIONS Comply with Division 1 - General Provisions and Covenants. 1.05 DELIVERY, STORAGE, AND HANDLING Comply with Division 1 - General Provisions and Covenants. 1.06 SCHEDULING AND CONFLICTS Comply with Division 1 - General Provisions and Covenants. 1 DRAFT

DRAFT Division 7 - Streets and Related Work Section 7080 - Permeable Interlocking Pavers 1.07 SPECIAL REQUIREMENTS A. Qualifications of Paver Installer: 1. Experience: Successful completion of paver installations similar in design, material, and extent. Provide project location, owner name, and email contact information. 2. Certification: Successful completion of a permeable paver installation certification course developed by the Interlocking Concrete Paver Institute or the School for Advanced Segmental Paving. B. Test Section: Install a 5 foot by 5 foot mock-up paver area on the prepared substrate to determine joint sizes, lines, laying patterns, paver edge treatments, colors, and texture of the project. If approved by the Engineer, it may be incorporated into the project. 1.08 MEASUREMENT AND PAYMENT A. Class 10, Class 12, or Class 13 Excavation: Comply with Section 2010, 1.08, E. B. Engineering Fabric: 1. Measurement: Measurement will be in square yards for the surface area covered with engineering fabric. Both horizontal and vertical areas covered with engineering fabric will be measured. 2. Payment: Payment will be made at the unit price per square yard of engineering fabric. 3. Includes: Unit price includes, but is not limited to, placing and securing filter fabric and any overlapped areas. C. Underdrain: 1. Measurement: Each type and size of pipe installed will be measured in linear feet from end of pipe to end of pipe along the centerline of pipe, exclusive of outlets. The vertical height of cleanouts; the vertical height of observation wells; and lengths of elbows, tees, wyes, and other fittings will be included in the length of pipe measured. 2. Payment: Payment will be made at the unit price of each type and size of pipe. 3. Includes: Unit price includes, but is not limited to, furnishing and placing pipe, cleanouts, observation wells, and pipe fittings. D. Storage Aggregate: 1. Measurement: Measurement will be in tons based upon scale tickets for the material delivered and incorporated into the project. 2. Payment: Payment will be made at the unit price per ton of storage aggregate. 3. Includes: Unit price includes, but is not limited to, furnishing, hauling, placing, and compacting storage aggregate. 2 DRAFT

DRAFT Division 7 - Streets and Related Work Section 7080 - Permeable Interlocking Pavers 1.08 MEASUREMENT AND PAYMENT (Continued) E. Filter Aggregate: 1. Measurement: Measurement will be in tons based upon scale tickets for the material delivered and incorporated into the project. 2. Payment: Payment will be made at the unit price per ton of filter aggregate. 3. Includes: Unit price includes, but is not limited to, furnishing, hauling, placing filter, and compacting aggregate. F. Permeable Interlocking Pavers: 1. Measurement: Measurement will be in square yards for the area of each type of permeable interlocking pavers installed. The area of manholes, intakes, or other fixtures in the pavement will not be deducted from the measured pavement area. 2. Payment: Payment will be made at the unit price per square yard of each type of permeable interlocking pavers. 3. Includes: Unit price includes, but is not limited to, testing, placement of bedding course, installing permeable interlocking pavers, placing joint/opening fill material, refilling joint after 6 months, and pavement protection. G. PCC Edge Restraint: 1. Measurement: Measurement will be in linear feet for each type and size of PCC edge restraint. The area of manholes, intakes, or other fixtures in the pavement will not be deducted from the measured pavement area. 2. Payment: Payment will be at the unit price per linear feet for each type and size of PCC edge restraint. 3. Includes: Unit price includes, but is not limited to, final trimming of subgrade or subbase, bars and reinforcement, joints and sealing, surface curing and pavement protection, safety fencing, and boxouts for fixtures. 3 DRAFT

DRAFT Division 7 - Streets and Related Work Section 7080 - Permeable Interlocking Pavers PART 2 - PRODUCTS 2.01 ENGINEERING FABRIC Comply with Iowa DOT Section 4196, requirements for subsurface drainage. 2.02 UNDERDRAIN A. Provide slotted or perforated pipe(s) complying with the requirements for Type 1 Subdrain in Section 4040. B. Provide 6 inch diameter collector pipes unless otherwise specified in the contract documents. C. Provide 4 inch diameter lateral pipes unless otherwise specified in the contract documents. 2.03 AGGREGATE Provide crushed stone with 90% fractured faces. Wash all stone materials to ensure less than 2% passing the No. 200 sieve. A. Storage Aggregate: Aggregate complying with Iowa DOT Section 4122, Gradation No. 13, Class 2 durability (AASHTO M 43/ASTM D 448, Size 2). B. Filter Aggregate: Aggregate complying with Iowa DOT Section 4115, Gradation No. 3, Class 2 durability (AASHTO M 43/ASTM D 448, Size 57). C. Bedding/Joint/Void Filler Aggregate: Crushed stone complying with Iowa DOT Section 4125, Gradation No. 29 (AASHTO M 43/ASTM D 448, Size 8). 2.04 PERMEABLE INTERLOCKING PAVERS A. Interlocking Concrete Pavers: Comply with ASTM C 936 for minimum 3 1/8 inch thick pavers. B. Clay Brick Pavers: Comply with ASTM C 1272 for minimum 2 3/4 inch thick, Type F brick for PX applications. 2.05 PCC EDGE RESTRAINT Provide PCC edge restraint complying with Section 7010. A PCC edge restraint may be standard curb and gutter section, a vertical curb section, or a narrow concrete slab. 4 DRAFT

DRAFT Division 7 - Streets and Related Work Section 7080 - Permeable Interlocking Pavers PART 3 - EXECUTION 3.01 PRE-INSTALLATION PROTECTION A. Complete grading, utility installation, and other earth disturbing operations prior to excavating for the permeable paver system. B. Prior to placing permeable interlocking pavers, install sediment control practices upstream to protect the area from sediment in stormwater runoff from disturbed soil. 3.02 SUBGRADE PREPARATION FOR PERMEABLE INTERLOCKING PAVERS A. Excavate area to the elevations and grades specified in the contract documents. B. When underdrain is specified, excavate a minimum 12 inch wide by 8 inch deep trench at locations specified in the contract documents. C. Where fill materials are required, compact materials to 95% of maximum Modified Proctor Density. Do not over compact. D. Fill and lightly re-grade any areas damaged by erosion, ponding, or traffic compaction prior to placing the engineering fabric. 3.03 ENGINEERING FABRIC A. Install engineering fabric over completed subgrade, including trench for underdrain when specified. B. Overlap adjacent strips of fabric a minimum of 12 inches. C. Extend fabric up the sides of the subbase trench to the bottom of the proposed pavement. 3.04 UNDERDRAIN A. Underdrain Collector Pipes: 1. Place 2 inches of filter aggregate in the bottom of the underdrain trench over engineering fabric. 2. Begin underdrain collector installation at the outlet and continue upgrade. 3. Lay underdrain collector pipe to the proper line and grade. Place pipe with perforations down. 4. Place filter aggregate over installed pipe in layers no more than 6 inches thick. Thoroughly tamp each layer with mechanical tampers. 5. Provide cleanouts where specified in the contract documents. Comply with Figure 4040.232. 6. Connect underdrain collector to outlet. Comply with Figure 4040.233. Install rodent guard on all underdrain pipe 6 inches or smaller. 7. Install underdrain cleanout pipes and observation wells as specified in the contract documents. 5 DRAFT

DRAFT Division 7 - Streets and Related Work Section 7080 - Permeable Interlocking Pavers 3.04 UNDERDRAIN (Continued) B. Underdrain Lateral Pipes: 1. Place 2 inches of filter aggregate over the bottom of the prepared subgrade at lateral pipe locations specified in the contract documents. 2. Lay underdrain lateral over filter aggregate to the proper line and grade. Place pipe with perforations down. 3. Connect underdrain laterals to underdrain collector with wye or tee fitting. 4. Install plug or cap on upstream end of lateral pipe. 5. Place additional filter aggregate along each side of the lateral pipe to the springline of the pipe. 3.05 STORAGE AGGREGATE A. Place storage aggregate in 6 inch maximum lifts to the thickness specified in the contract documents. If underdrain system is specified, take care not to damage or displace pipe during placement of storage aggregate. B. Compact each lift with a vibratory drum roller until no visible movement can be seen in the aggregate layer. Do not crush aggregate. Do not operate compaction equipment directly over underdrain, until a minimum of 12 inches of storage aggregate is placed over the underdrain. C. Install storage aggregate to the elevation specified in the contract documents. 3.06 FILTER AGGREGATE A. Place filter aggregate directly over storage aggregate. B. Install aggregate in a single lift with a thickness of 4 inches. C. Lightly compact filter aggregate with one or two passes from a vibratory plate compactor or vibratory roller. If a vibratory roller is utilized, perform the final pass without vibration. Do not crush aggregate. 3.07 BEDDING AGGREGATE A. Place bedding aggregate directly over filter aggregate. B. Install aggregate in a single lift with a thickness of 2 inches. C. Use laser guided spreader or place screed rails on the completed filter aggregate layer. Use screed width no less than the full width of each cross-section component of the roadway and no less than 16 feet for parking areas. Surface variations must be within 3/8 inch when tested with a 10 foot straightedge prior to compaction. D. Lightly compact bedding aggregate with one or two passes from a vibratory plate compactor or vibratory roller. Recheck tolerance following compaction and make necessary corrections. Ensure surface is even, smooth with no roller ridges, and at the proper elevation to accommodate the pavers. E. Restrict pedestrians and equipment from screeded bedding prior to placement of pavers. 6 DRAFT

DRAFT Division 7 - Streets and Related Work Section 7080 - Permeable Interlocking Pavers 3.08 INSTALLING PCC EDGE RESTRAINT Place PCC edge restraint according to Section 7010. 3.09 INSTALLING INTERLOCKING PERMEABLE PAVER SYSTEM Place and install pavers according to the pattern specified, the paver manufacturer s published installation specifications, and the following: A. Where pavers are placed against a curb and gutter or other pavement, installation of an edge course or soldier course is required if the pavement edge is not straight. Trim pavers as required to compensate for deviations in the adjacent pavement edge. Do not cut pavers to less than 1/3 their original size. B. Install PCC edge restraint. C. Place chalk lines on the bedding course to maintain straight joint lines. D. After pavers have been installed on the bedding course, and all cut pavers have been inserted to provide a full and complete surface, inspect pavers for damaged units and irregular joint lines. Remove and replace pavers as required. E. After inspection and replacement of damaged pavers, fill joint openings with bedding stone. Sweep the surface clean. F. Compact pavement surface with two passes of a vibratory plate compactor capable of at least 5,000 pounds centrifugal compaction force. Do not operate plate compactor within 6 feet of an unrestrained pavement edge. G. Re-inspect pavers, and remove and replace all damaged units. Refill joint openings completely. Sweep pavers clean. Complete compaction with two passes of the plate compactor. H. Refill all paver joint openings with bedding aggregate 6 months after installation. 3.10 QUALITY CONTROL A. Ensure horizontal alignment of the PCC edge restraint is within 1/2 inch of design alignment. B. Ensure final surface is within 3/8 inch when tested with a 10 foot straightedge. C. Ensure no greater than 1/8 inch difference in height between adjacent pavers. D. Maintain surface elevation within 1/4 inch above adjacent drainage inlets, gutters, and other appurtenances. 3.11 PROTECTION OF PAVEMENT A. Protect pavement from heavy construction traffic, including trucks, skid steers, loaders, and all tracked vehicles. B. Provide barriers and protection as necessary. 7 DRAFT

DRAFT Division 7 - Streets and Related Work Section 7080 - Permeable Interlocking Pavers 3.11 PROTECTION OF PAVEMENT (Continued) C. Do not place soil, mulch, sand, aggregate, or stockpile other materials on the pavement surface that may contaminate the pavement and plug the porous surface. D. Remove by vacuuming any base and bedding materials contaminated with sediment and replace with clean materials at no cost to the contracting authority. END OF SECTION 8 DRAFT

REVISION Refer to the contract documents for dimensions, grades, and additional requirements for permeable interlocking pavers and associated improvements. 1 Permeable interlocking pavers as specified in the contract documents. 2 2 inch minimum permeable pavement bedding aggregate to accomodate imperfections in the permeable pavement filter aggregate layer. 3 Permeable pavement storage aggregate thickness as specified in the contract documents. 4 When underdrain collectors and/or laterals are specified, install to the line and grade specified in the contract documents. Place permeable pavement filter aggregate to springline of pipe. Possible PCC curb and gutter or adjacent 6 pavement. 1 Set 4" below pavers Slope at 0% or as specified in the contract documents. 5 6 Place 4 inches of filter aggregate under curb and gutter section. Extend to 12 inches beyond the back of curb. Extend engineering fabric under aggregate. Install paver edge restraint system along unrestrained edges. 12" Permeable interlocking pavers Bedding Aggregate 2 4" Layer of Filter Aggregate 1 FIGURE 7080.101 SHEET 1 OF 1 5 Place filter aggregate around underdrain. 8" Place engineering fabric over subgrade and up sides of excavation. 12" 2" minimum Install 6" perforated underdrain collector when specified. 4 Install 4" slotted underdrain laterals and filter material when specified. 4 Slope subgrade as specified. Storage Aggregate 3 New 10-20-15 7080.101 SHEET 1 of 1 SUDAS Standard Specifications PERMEABLE INTERLOCKING PAVERS

REVISION Refer to the contract documents for dimensions, grades, and additional requirements for permeable interlocking pavers and associated improvements. 1 2 3 4 Permeable interlocking pavers as specified in the contract documents. 2 inch minimum permeable pavement bedding aggregate to accomodate imperfections in the permeable pavement filter aggregate layer. Permeable pavement storage aggregate thickness as specified in the contract documents. Set PCC edge restraint 1/4 inch below pavers. Alley Width (as specified) 2'-0" Bedding Aggregate 2 2'-0" 4 0% Slope Permeable Pavers 1 4 2% Slope 2% Slope 6" PCC Edge Restraint 4" Layer of Filter Aggregate Storage Aggregate 3 FIGURE 7080.102 SHEET 1 OF 1 Place engineering fabric over subgrade and up sides of excavation. Place filter aggregate around underdrain. 8" Slope subgrade at 1%. Install 6" perforated underdrain collector. New 10-20-15 7080.102 SHEET 1 of 1 SUDAS Standard Specifications TYPICAL ALLEY WITH PERMEABLE PAVERS