Pavement Maintenance and Rehabilitation Plans

Pavement Maintenance and Rehabilitation Plans

It is important to understand the expected pavement performance and costs for the entire life cycle of the pavement. The overall costs and value need to be determined over many years to effectively consider the different options in terms of pavement type, design life, and future maintenance and rehabilitation. Life-cycle cost analysis (LCCA) has been used for many years to help make decisions regarding pavement type as well as selecting pavement preservation options. Broadly, the overall costs are divided into initial or typically capital costs and future or typically operational costs. Initial costs are typically covered by specific capital budgets and, in the municipal environment, in many cases by developers who design and construct the roadway infrastructure to municipal specifications. Therefore, for the purpose of this analysis, only future operational costs are included in the LCCA. In a typical LCCA, two or more alternate choices are available for an initial pavement design or cross-section. At the end of the initial service life, some form of rehabilitation, such as a mill and overlay for a flexible pavement, replacement of worn or cracked pavers for ICP and slab repairs and possible diamond grinding for smoothness and surface friction restoration for a rigid pavement, is usually required. Based on the initial pavement designs, the expected maintenance and rehabilitation over the design life are then determined and incorporated into a single, inflation-adjusted cost in order to evaluate and compare the different options in a fair and consistent manner. An analysis period of 50 years was used for the roadways/parking areas and 40 years for the sidewalks/ trails.

Low Volume Roads/Parking Areas

Typical maintenance plans for low volume roads/parking areas are provided in the sections below. The maintenance schedule for asphalt concrete and concrete over aggregate base/subbase are based on a technical report titled “Methodology for the Development of Equivalent Pavement Structural Design Matrix for Municipal Roadways including Maintenance and Rehabilitation Schedules and Life-Cycle Cost Analysis”, for the Ready Mixed Concrete Association of Ontario & Cement Association of Canada” (RMCAO/CAC) in 2011.

Interlocking Concrete Pavers on Aggregate Base/Subbase

ICPs have been used by many municipalities across North America. Use of ICP for municipal pavements is typically based on development requirements for a high-quality appearance in specific areas of the city attracting tourist and retail type activities. The recommended maintenance and rehabilitation schedule for ICP on a granular base/subbase are outlined in Table 3 below. This plan was developed based on a research study completed by ICPI to develop an ICP pavement surface distress identification manual in 2008. This manual was the predecessor to the development of ASTM E2840 Standard Practices for Pavement Condition Index Surveys for Interlocking Concrete Roads and Parking Lots. The

maintenance and rehabilitation quantities provided are for a 1 km length of 2-lane roadway and will need to be adjusted for different section lengths or areas in the case of a parking lot if necessary.

Table 3. ICP Roadway/Parking Area Maintenance Plan (Aggregate Base/Subbase).

Expected Quantity Activity Description

Year (per 2 lane 1 km of road)

8 Reset Pavers 2 %

18 Replace Worn/Rutted Pavers (wheelpath) 18 Reset Pavers 5 % 5 %

18 Joint Sand Replenishment 28 Replace Cracked Pavers 28 Reset Pavers 25 % 2 % 5 %

28 Joint Sand Replenishment 38 Replace Worn/Rutted Pavers (wheelpath) 38 Reset Pavers 38 Joint Sand Replenishment 48 Replace Cracked Pavers 25 % 5 % 5 % 25 % 3 %

Interlocking Concrete Pavers on Concrete Base

The recommended maintenance and rehabilitation schedule for ICP on a concrete base/subbase are outlined in Table 4.

Table 4. ICP Roadway/Parking Area Maintenance Plan (Concrete Base/Subbase). Expected Quantity Activity Description

Year (per 2 lane 1 km of road)

8 Reset Pavers 2 %

18 Replace Cracked Pavers 18 Reset Pavers 5 % 5 %

18 Joint Sand Replenishment 28 Replace Cracked Pavers 28 Reset Pavers 5 % 2 % 5 %

28 Joint Sand Replenishment 38 Full Depth PCC Repair 38 Replace Cracked Pavers 25 Reset Pavers 38 Joint Sand Replenishment 48 Replace Cracked Pavers 10 % 10 % 5 % 5 % 10 % 3 %

Asphalt Concrete on Aggregate Base/Subbase

Asphalt Concrete (AC) pavements have been commonly used by municipalities due to their history of use and experience with maintenance and rehabilitation. Asphalt pavements typically deteriorate faster than ICP and PCC pavements and require a more extensive maintenance schedule to maintain an acceptable level of service. The recommend maintenance and rehabilitation schedule for AC on a granular base/subbase is shown in Table 5. The AC pavement maintenance plans are developed based on the RMCAO/CAC report. The maintenance plan includes a combination of preventive maintenance and rehabilitation. The quantities provided are for a 2-lane 1 km length roadway and will need to be adjusted for different section lengths or areas in the case of a parking lot if necessary.

Table 5. AC Roadway/Parking Area Maintenance Plan (Aggregate Base/Subbase). Expected Quantity Activity Description

Year (per 2 lane 1 km of road)

10 Rout and seal 250 m 10 Spot repairs, mill 40 mm/patch 40 mm 2 % 20 Mill AC 40 mm 20 Resurface with AC surface course 40 mm 25 Rout and seal 500 m 30 Spot repairs, mill 40 mm/patch 40 mm 5 % 35 Mill AC 40 mm 35 Full depth asphalt base repair 5 % 35 Resurface with AC surface course 40 mm 40 Rout and seal 500 m 43 Spot repairs, mill 40 mm/patch 40 mm 5 % 48 Mill AC 40 mm 48 Resurface with AC surface course 40 mm

Portland Cement Concrete on Aggregate Base

Concrete pavements have been used by municipalities intermittently across North America often depending on local pricing, availability of aggregates and local contractors capable of placing concrete pavements. The recommended maintenance and rehabilitation schedules for PCC pavements are outlined in Table 6.

The maintenance plan includes a combination of preventive maintenance and rehabilitation. The maintenance and rehabilitation quantities provided are for a 2-lane 1 km length roadway and will need to be adjusted for different section lengths or areas in the case of a parking lot if necessary.

Table 6. PCC Roadway/Parking Area Maintenance Plan (Aggregate Base). Expected Quantity Activity Description

Year (per 2 lane 1 km of road)

12 Reseal joints 25 Partial depth PCC repair 25 Full depth PCC repair 25 Reseal joints 40 Partial depth PCC repair 40 Full depth PCC repair 40 Reseal joints 20 % 2 % 5 % 40 % 5 % 10 % 40 %

Sidewalks/Recreational Trails

Typical maintenance plans for sidewalks/recreational trails are provided for each type of pavement in the sections below.

Interlocking Concrete Pavers on Aggregate Base/Subbase

ICPs have been used for sidewalks by municipalities intermittently across North America. Usage of ICP for municipal sidewalks is typically based on development requirements for a high-quality appearance in specific areas of the city attracting tourist and retail type activities. The recommended maintenance schedule for interlocking concrete sidewalks is outlined in Table 7. The maintenance quantities provided are for a 100 m length and will need to be adjusted for different section lengths or areas if necessary.

Table 7. ICP Sidewalk/Recreational Trail Preservation Plan (Aggregate Base).

Expected Quantity Activity Description

Year (per 100 m length)

10 Reset Pavers (m²) 5 % 15 Replace Cracked Pavers (m²) 3 % 15 Joint Sand Replenishment (m²) 5 % 20 Reset Pavers (m²) 15 % 25 Joint Sand Replenishment (m²) 15 % 30 Reset Pavers (m²) 15 % 35 Replace Cracked Pavers (m²) 15 % 35 Joint Sand Replenishment (m²) 15 %

Interlocking Concrete Pavers on Concrete Base The recommended maintenance and rehabilitation schedule for ICP on a concrete base/ subbase are outlined in Table 8.

Table 8. ICP Sidewalk/Recreational Trail Maintenance Plan (Concrete Base/Subbase). Expected Quantity Activity Description

Year (per 100 m length)

10 Slab jacking (m2) 5 % 10 Reset Pavers (m2) 5 % 15 Slab jacking (m2) 10 % 15 Reset Pavers (m2) 10 % 25 Concrete Panel Replacement (m2) 5 % 25 Slab jacking (m2) 10 % 25 Reset Pavers (m2) 10 % 35 Concrete Panel Replacement (m2) 10 % 35 Slab jacking (m2) 10 % 35 Reset Pavers (m2) 10 %

Asphalt Concrete on Aggregate Base/Subbase

Asphalt concrete while rarely used for sidewalks, is the pavement type of choice for hard surfaced recreational trails. Recreational trails are typically wider than sidewalks in the order of 3 to 4.5 m in width. However, for comparison purposes, a 1.5 m width of recreational trail was used for the maintenance calculations. The recommended maintenance schedule for AC trails is outlined in Table 9. The maintenance quantities provided are for a 100 m length and will need to be adjusted for different section lengths or areas if necessary.

Table 9. AC Recreational Trail Maintenance Plan (Aggregate Base/Subbase). Expected Quantity Activity Description

Year (per 100 m length)

10 Transverse crack rout and seal 7.5 m 10 Spot repairs, mill 40 mm and patch 40 mm 2 % 20 Mill AC 40 mm 20 Resurface with AC surface course 40 mm 25 Transverse crack rout and seal 15 m 30 Spot repairs, mill 40 mm and patch 40 mm 5 % 35 Mill AC 40 mm 35 Full-depth asphalt base repair 5 % 35 Resurface with AC surface course 40 mm 40 Transverse crack rout and seal 15 m

Portland Cement Concrete on Aggregate Base

PCC while rarely used for recreational trails is the pavement type of choice for hard surfaced sidewalks in North America. The recommended maintenance schedule for concrete sidewalks is outlined in Table 10. The maintenance quantities provided are for a 100 m length for comparison purposes and should be adjusted for the actual project section lengths.

Table 10. PCC Sidewalk Maintenance Plan (Aggregate Base).

Expected Year

Activity Description

10 Slab jacking (m2) 10 Concrete edge grinding (per 1-1.5m) 15 Slab jacking (m2) 15 Concrete edge grinding (per 1-1.5m) 25 Concrete panel replacement (m2) 25 Slab jacking (m2) 25 Concrete edge grinding (per 1-1.5m) 35 Concrete panel replacement (m2) 35 Slab jacking (m2) 35 Concrete edge grinding (per 1-1.5m)

Quantity (per 100 m length) 5 % 5 % 5 % 15 % 10 % 10 % 15 % 15 % 10 % 10 %

Life-Cycle Cost

Life-cycle costing (LCC) has become an essential component of any modern infrastructure design. It has long been realized that maintenance and rehabilitation costs, not just the immediate initial construction costs should be considered when evaluating investment alternatives. The service life of a pavement is defined as the time between initial construction and the time when the pavement reaches a minimum unacceptable level of service. Municipal pavements are typically designed for an initial service life of 20 to 30 years. At the end of the initial service life, some form of rehabilitation action such as removal and resetting of concrete pavers for ICP, mill and overlay for AC pavements and concrete pavement restoration (CPR) consisting of full or partial depth repairs, load transfer retrofit, etc. for PCC is completed. The actual service life of the pavement is dependent on a variety of factors including type and composition of the traffic, timeliness of maintenance treatments, and environmental factors such as climate, temperature and precipitation. To develop comparative cost estimates to determine the whole life cost of different pavement types, it is necessary to know the timing, type and quantities of repairs and their service life. Life-cycle costing is a technique that quantifies all the costs necessary to construct and maintain a pavement over a set analysis period, typically between 30 and 50 years. Future costs are discounted to today’s dollars by using a discount rate which accounts for the effects inflation (future value of money) and interest rates (the cost of borrowing money) to determine the net present value of future costs. By comparing the total life-cycle cost of two or more pavement options, it is possible to make informed decisions on the best pavement alternative for a particular application. Life-cycle costing can be used to benchmark potential pavement options to determine which is the most cost effective. Traditionally, when performing a life-cycle cost analysis comparing pavement surface types, the capital costs for initial construction and maintenance and rehabilitation costs for each of the pavement types are considered.