Design and Construction Services

Construction Services administers and inspects the following projects which are tendered by Design Services:

Disclaimer

Asphalt Resurfacing generally consists of the following steps:

1. Milling off selected areas of old asphalt either along the curb or within the street
2. Patching any pot holes or badly deteriorated areas
3. Adjusting any street hardware (manhole frames, catch basin frames) to the new grade of the asphalt
4. Placing and compacting hot mix asphalt pavement
5. Completing any restoration of adjacent properties

Asphalt used for resurfacing is generally placed in 40 mm to 50 mm thick lifts. Street resurfacing can improve driving conditions and correct improper drainage and will last generally for 10 to 12 years depending on traffic, weather conditions and the proper strategy of treatments.

Inconvenience with a resurfacing project is generally minimal to medium. The noise and fumes of heavy equipment are sometimes factors. Streets which are 'under construction' for sometimes 3 to 4 weeks can cause problems for both the public and the Municipality. This can be termed 'the nature of the beast'. There is a certain amount of inconvenience, which we have accepted, to get the best possible value for the dollar. This is something that we take very seriously and monitor on a constant basis.

See where Resurfacing fits into the life cycle of street repairs.

Crack Sealing is generally made up of the following steps:

1. Rout out selected cracks with a saw to a specified depth
2. Clean out and dry the crack with high pressure air and heat
3. Place hot pour crack sealant
4. Place sand over the sealant to reduce stickiness

Normally inconvenience with a crack sealing is minimal. The noise and dust of the saw which routs out the crack is usually the only factor. The time spent on a street is generally only a few hours but may be longer due to the amount of traffic and the amount of cracks to be sealed.

Surface Sealing can be broken down into two groups:

• Micro Surfacing
• Slurry Sealing

1. Crack sealing any selected cracks
2. Patching any pot holes or deteriorated areas
3. Adjusting selected street hardware (manhole frames, catch basin frame) to the new grade of the Micro Surfacing.
4. Placement of the Micro Surfacing

Micro Surfacing is a modified polymer emulsified asphalt and is a relatively new treatment. It acts as a wearing surface and seals the existing asphalt surface, and is usually placed in 10 mm to 15 mm thick lifts. Micro Surfacing is self supporting up to a point so it can be used to fill in wheel ruts. It can last 5 to 7 years depending on traffic, weather conditions and the proper strategy of treatments.

Micro Surfacing is a slurry mixture that will take approximately 20 to 30 minutes to harden once placed. It is within this time frame which Micro Surfacing can cause problems for the public. If it is stepped in, it will track like tar until hardened. Tires will also pick it up easily. If in doubt whether it is hardened or still wet, it is best to stay off.

See where Micro Surfacing fits into the life cycle of street repairs.

Slurry Sealing is essentially the same as Micro Surfacing. The primary difference is how the material can be used. Micro Surfacing can be classified as heavy duty, while Slurry Seal can be classified as light duty. Slurry Seal is usually placed in a maximum thickness of 10mm and can be used on streets where the traffic volume is light, but doesn't hold up as well as Micro Surfacing on the heavier traffic volume streets.

Reconstruction - Paving Renewals

Paving Renewals are tendered by Design Services. Construction Services and Design Services will normally work closely on the project. Once the project is awarded by Regional Council, Construction Services will administer the actual construction.

Paving Renewal projects generally consists of the following steps:

1. Milling off all asphalt and replacing any gravel, curb and sidewalk as required
2. Placing and compacting Hot Mix Asphalt
3. Completing restoration of adjacent properties

Paving Renewals, in some cases, will have underground conduit, sewer pipe or water main installed in association with the street reconstruction. This requires coordination with the other utilities such as NSPI, Aliant or the Regional Water Commission and could significantly increase the length of time for the project to be completed.

The amount of inconvenience for a project of this type is usually the greatest among the different street treatments. Generally access to property is maintained, but inevitably, when concrete is poured or pipe is laid, complete access is limited. Dust and the noise of heavy equipment are other factors.

See how a Paving Renewal fits into the life cycle of street repairs.

Reconstruction - Pulverization & Stabilization

• Full Depth Reclamation (FDR)

1. Thickness and condition of the existing asphalt
2. The grade of the street compared to the adjacent properties
3. Whether the street has concrete curb or not

Full Depth Reclamation generally consists of the following steps:

1. Sample the existing asphalt to establish the best design for the particular location
2. Pulverize the roadway including the existing asphalt surface and approximately 150mm of the road sub base
3. Pulverize again, and introduce a foamed asphalt emulsion mixture
4. Grade the roadway to its new profile and compact. The roadway now sits for approximately 1 to 3 days to set up
5. Place and compact approximately 50mm of hot mix asphalt.

If you would like more information on Pulverization, Prime Materials of Texas USA has a very good background on this and other Recycling methods.

Main Artery Patching of streets is generally made up of the following steps:

1. Mill out any deteriorated areas
2. Adjust selected street hardware (manhole frames, catch basin frame) to the new grade of the asphalt
3. Place hot mix asphalt pavement

   Patching projects are usually tendered in groups of 10 to 20 individual streets and can take up to 4 to 6 weeks to complete the entire project. A contractor will generally complete steps 1 and 2 first and follow shortly after with step 3.

Patching can take place anywhere on the roadway which means traffic control around the work area will often result in partial street closures. Contract patching is usually done on major roadways, so this can cause traffic delays. The noise of heavy equipment can also be an inconvenience. Generally patching a particular section of street will, at the most, take place within 2 days.

Contract Patching is not directly influenced by the life cycle models as the rest of the street treatments are; as patching is usually encompassed within the other treatments.

New Paving

• New Paving Gravel Roads

New Paving Gravel Roads generally consist of the following steps:

1. Scarify existing roadway surface
2. Place and compact gravel
3. Place and compact hot mix asphalt
4. Complete restoration of adjacent properties

New Paving Gravel Roads is a fairly straight forward process, if the existing gravel roadway is in good condition. Approximately 100 mm of gravel is placed, then 85 mm of asphalt is placed and compacted. New Paved streets will last for 20-30 years depending on traffic, weather conditions and the proper strategy of treatments.

Local improvement, or betterment charges are applied to abutters for the New Paving Gravel Road projects.

See how a New Paving fits into the life cycle of street repairs. 

Sidewalk Renewals are generally made up of the following steps:

1. Excavating the existing concrete sidewalk and curb if required
2. Placing gravels for the new curb and sidewalk
3. Pouring concrete for the new curb
4. Pouring concrete for the new sidewalk
5. Completing restoration of adjacent properties, including topsoil and sodding

Sidewalk Renewals are usually tendered in groups of 2 to 6 individual locations and can take up to 6 to 8 weeks to complete.

The new concrete sidewalk is usually 100 mm thick with 150 mm of gravel underneath. Driveway entrances are usually 150 mm thick with 150 mm of gravel underneath.

The size of new driveway entrances for residential properties are usually a minimum of 3 meters and a maximum of 4 meters wide. Business properties can have driveway entrances from 3 to 5 meters wide. An owner of a property can usually have the location of the driveway moved or the size increased or decreased, within guidelines, when the curb is being prepared for pouring. The inspector tries to contact each property owner prior to the concrete being poured to see if any changes are required. Each request is looked at separately; sometimes a request cannot be granted due to conflicts with the adjacent structures or property.

Generally, the biggest inconvenience with a sidewalk renewal is having access to property and parking is reduced or cut off; this is for a short period of time, usually only overnight once or twice during the length of the project.

New Sidewalks are generally made up of the following steps:

1. Excavating, or in filling. for the placement of sidewalk and curb
2. Placing gravels for the new curb and sidewalk
3. Pouring concrete for the new curb
4. Pouring concrete for the new sidewalk
5. Completing restoration of adjacent properties, including topsoil and sodding.

New Sidewalks are usually tendered in groups of 2 to 4 individual locations and can take up to 3 to 5 weeks to complete. The scope of work for a New Sidewalk may include sidewalk and curb; or it may just include sidewalk.

Generally the scope of work for a new sidewalk project is similar to a sidewalk renewal project. The main difference will be lack of any existing concrete sidewalk prior to construction. There may be no sidewalk at all or the existing sidewalk may be gravel or asphalt.

Local improvement, or betterment charges are applied to abutters for the New Sidewalk projects.

Storm and/or Sanitary Sewer projects can be broken down into two groups :

• Conventional Excavation
• Sewer lining

Conventional Excavation is generally made up of the following steps:

1. Excavating trench for installation of pipe
2. Installation of pipe
3. Back filling of trench
4. Completing restoration of the street or adjacent properties

Sewer projects are sometimes combined with Street Reconstruction projects or projects tendered by the Regional Water Commission. This requires coordination with these departments and could significantly increase the length of time for the project to be completed.

Inconveniences could include noise from any drilling or rock breaking which is required and temporary loss of access to property due to pipe trenches.

Sewer lining is generally made up of the following steps:

1. Clean the existing sewer line
2. Prepare the existing sewer line for lining
3. Install new liner
4. Cut out existing laterals

This project eliminates the excavation process which can take more time as well as cause traffic problems. Generally, sewer lining is only used when the existing pipe remains the same size, or is reduced in size. Sewer lining can also be used during the pipe bursting process, though, this process has not been used in this area.

Upgrade Paving

• Stone & Oil or Chip sealed streets

Upgrade Paving of Stone & Oil or Chip sealed streets generally consists of the following steps:

1. Mill off the roadway surface
2. Placing and compacting gravels for the roadway if required
3. Pouring concrete curb and sidewalk, if necessary
4. Placing and compacting Hot Mix Asphalt pavement
5. Completing restoration of adjacent properties

Generally streets which are Stone & Oil or Chip sealed are older streets and are in a variety of conditions. The street may have storm and sanitary sewer or the sewer may have to be installed within the project. It may have the standard HRM right of way width or the existing street may have to be widened to meet the standard right of way width. It may have curb or it may not.

New Paved streets will last for 10-30 years depending on traffic, weather conditions and the strategy of treatments.

Traffic Improvements can vary greatly from project to project.

Different projects could include :

• Installing traffic signals at an intersection
• Installing pedestrian crosswalk signals
• Widening an existing roadway at an intersection for a right turning or left turning lane
• Widening an existing roadway, for example from 2 lanes to 4 lanes
• Closing an existing street to traffic

The scope of work for these projects could vary from:

• Traffic or Pedestrian Signals - excavating shallow trenches across the roadway for conduit and pouring concrete bases for signals - costing $20,000
• Widening existing roadways - expanding a 2 lane roadway to 4 lanes complete with new sewer, water main, concrete retaining walls, in filling. etc.- costing $3 to $4 million dollars.

Independent Consultants are sometimes engaged to study a traffic problem and make recommendations to rectify the problem, they could design, tender and inspect the project. Construction Services would liaise with the consultant during the project.

Streets & Roads would also handle smaller traffic improvements which could include erecting traffic signs or signals.

Recreation projects can vary greatly from project to project

Different projects could include:

• Construction new sport fields or sport courts
• Expanding existing sport fields or sport courts
• Correcting drainage problems on existing recreation facilities

The scope of work for these projects could vary from:

• New sport fields - taking an existing field or treed area, clearing the site, excavating for any required drainage, excavating and placing fill material and gravels for the sport field and placing the sport field floor.
• Correcting Drainage Problems - if a sport court has water ponding , excavate for the required drainage pipe, possibly install a catch basin and reinstate the site .

Real Property Operations would also handle smaller recreation projects which could include correcting drainage problems, sodding and sport fields or sport courts upgrading.

Miscellaneous projects can vary greatly from project to project

Different projects could include:

• Building or Repairing Retaining Walls
• Building Small Boat Landings
• Repairing Shore Lines
• HRM owned parking lot upgrading
• Bridges
• Walkways

The scope of work for these projects could vary from:

• Building or Repairing Retaining Walls - excavating the existing wall owned by HRM (which could be rock, Gabon, steel etc.), preparing the wall sub grade, placing drainage control, pouring or building the new wall.
• Repairing Shore Lines - HRM has property and facilities which abut the shoreline. For example, sewer pipe that runs along the shoreline may have its protective cover deteriorated over time. This protective cover may be larger rock placed over the pipe in area which the pipe cannot be buried. The deteriorate areas will be cleaned up and any new rock which is required would be placed. A project like this requires specialized equipment and floating barges to work from the waters' edge.

Works would also handle smaller miscellaneous projects which could include correcting drainage problems or upgrading HRM property .