04 ATTACHMENT 6 - Laserfiche WebLink

Project No. E9164-04-0 2 - 13 - April 15, 2020 6.12 Pavement Recommendations 6.12.1 The upper 12 inches of pavement subgrade should be scarified, moisture conditioned to at least 2% above optimum and compacted to at least 95% relative compaction. Prior to placing aggregate base, the finished subgrade should be proof-rolled with a laden water truck (or similar equipment with high contact pressure) to verify stability. 6.12.2 Sidewalk, curb, gutter, and driveway encroachments should be designed and constructed in accordance with City of Pleasanton requirements, as applicable. 6.12.3 We recommend the following asphalt concrete (AC) pavement sections for design to establish subgrade elevations in pavement areas. The project civil engineer should determine the appropriate Traffic Index (TI) based on anticipated traffic conditions. The flexible pavement sections below are based on estimated design TIs and an R-Value of 5 for the subgrade soils. We can provide additional sections based on other TIs if necessary. TABLE 6.12 FLEXIBLE PAVEMENT SECTION RECOMMENDATIONS Location Estimated Traffic Index (TI) AC Thickness (inches) AB Thickness (inches) Parking Stalls 4.5 3 8 Driveways 6.0 3 ½ 12 ½ Heavy-Duty 7.0 4 15 ½ Note: The recommended flexible pavement sections are based on the following assumptions: 1. AB: Class 2 AB with a minimum R-Value of 78 and meeting the requirements of Section 26 of the latest Caltrans Standard Specifications. 2. AB is compacted to 95% or higher relative compaction at or near optimum moisture content. Prior to placing AB, the subgrade should be proof-rolled with a loaded water truck to verify stability. 3. AC: Asphalt concrete conforming to local agency standards or Section 39 of the latest Caltrans Standard Specifications. 6.12.4 The AC sections in Table 6.12 are final, minimum thicknesses. If staged-pavements are used, the construction bottom AC lift should be at least 2 inches thick. Following construction, the finish top AC lift should be at least 1½ inches thick. 6.12.5 Unless specifically designed and evaluated by the project structural engineer, where concrete paving will be utilized for support of vehicles, we recommend the concrete be a minimum of 6 inches thick and reinforced with No. 3 steel reinforcing bars placed 24 inches on center in both horizontal directions. In addition, doweling, reinforcing steel or other load-transfer mechanism should be provided at joints if desired to reduce the potential for vertical offset. The concrete should have a minimum 28-day compressive strength of 3,500 psi. 6.12.6 We recommend that at least 6 inches of Class 2 Aggregate Base (AB) be used below rigid exterior concrete pavements. The aggregate base should be compacted to at least 95% relative compaction near optimum moisture content. 6.12.7 Consideration should be given to providing a thickened edge on the outside of concrete slabs subject to wheel loads. The thickened edge should be 2 inches thicker than the design slab thickness at the slab edge and taper back to the design slab thickness 3 feet behind the face of the slab.