2. Highway Construction
Contents :
Introduction
The Steps to the Construction of a Road
Stages in Road Construction
The Construction of Roadways
Activities Associated With Road Construction
Road Compaction Techniques
Road Construction Technology
Disadvantages of Road Construction on Soil
Road Construction Procedures
How to Lay a Paved Road
Road Construction Safety Signs
Activities Associated With Road Construction
Common Physical Hazards at Construction Sites
Road Construction Safety Checklist
Safety Checklist for Construction
Common Construction Tools
3. 1:Introduction :
Asphalt concrete, commonly known simply as asphalt, is the most common road
surface. (Photo: Iakov Kalinin/iStock/Getty Images)
The basic construction process for building a road is similar for any road. The
differences arise in the finishing of the road or the surface materials used to finish a
road. The process begins with road design, including surveying the route, allowing
for drainage and considering the expected volume of traffic and planned
development in the area.
4. 2:The Steps to the Construction of a Road
Road construction involves many steps from planning to legal and environmental issues, to contract bidding, construction
and maintenance. Road construction takes time, and requires lots of people, organizations and steps.
•Planning
•Planning entails producing the original design concept which covers points like the road's length and width, the
corridor route and construction materials. It is necessary to identify sources of funding to cover the projected
operating budget.
Addressing Environmental issues and Preliminary Engineering
•Preliminary engineering begins with land surveying to identify issues standing in the way of project completion. It
may require clearing trees, buying privately owned property or documenting environmental impact and the ensuing
public hearings and federal review.
5. 3:Stages in Road Construction
Road construction has many stages and can take many years.
Road construction is a lengthy process that can take more than 10 years, depending on the size of the future pathway. It
involves several construction crews and plant machinery and requires careful planning and various evaluations, including
environmental and structural assessments. Once construction has begun, there are several stages before the road can be
used by vehicles.
•Clearing and Excavation
•The area on which the road is going to be built on must be cleared of all vegetation, which requires the removal of
trees, shrubs and bushes. Excavation vehicles will also dig up and remove rocks and stones from the future road's
pathway. To prevent the cleared land from erosion, control devices, including fences, ditches and basins are
installed.
Mounting
•The road takes shape as diggers, excavation plant machinery and bulldozers mount dirt and soil over the area where the future pathway will
run. The surface is then leveled and smoothed by graders. Culverts and drains, consisting of large concrete pipes, are laid to prevent the road
from flooding by leading away groundwater, sewage or stormwater.
6. 4:The Construction of Roadways
A variety of construction equipment is used to construct roads.
Road construction, whether for low-volume access roads or complex interstate highways, follows the same general sequence
of construction activities.
•Initial Activities
•At the start of construction, vehicle and pedestrian detours and environmental mitigation measures are implemented.
The road corridor is cleared of trees, shrubs and other vegetation. Underground utility work is completed and major
drainage structures, including storm sewers or drainage cross-culverts, are installed.
Major Structures and Paving
•Bridges and retaining walls are constructed. Curbs, gutters and sidewalks are placed. The roadway base soil is
prepared and a subgrade layer of material, such as gravel,
Final Construction Activities
•Pavement markings are installed on the final paved surface. Roadside signs, traffic signals, street lighting and
guardrails are erected. Landscaping anirrigation systems are installed.
7. Cement Concrete Paving
Cement concrete
Cement concrete uses cement and water as the binding agent for the aggregate mix. Concrete paving also
requires thick base layers of compacted aggregate to form a solid surface for the road. Workers must then
construct forms, or molds, along the edges of the planned road to prevent the concrete from spreading before it
sets. Cement concrete is broken up with regular joints, connected by wire baskets and dowels. This allows the
concrete to expand and contract during seasonal temperature changes without cracking the surface of the road.
The surface may be tined, or grooved, with a machine for better traction.
8. Tar and Chip/Macadam
Hot tar.
This style of paving has been used for many years, and it was the first type of paving installed on early roads.
Today, tar and chip are often used as a recoating material, not as the original pavement on public roads. However,
it is still a popular treatment for driveways and is regularly used for road repair on public roads because it is cost
effective and durable. In tar and chip paving, a thick layer of tar or bitumen is spread on the prepared base
surface, and then a layer of chips, or small stones, is spread over the tar and compressed into the tar with a roller.
The stones may be of varying sizes for different finished appearances. When this method is used for driveways,
sometimes colored or decorative stones are used. This can be a durable and cost-effective finishing method.
9. 5:Activities Associated
With Road Construction
Road construction can put a damper on your commute.
Road construction is a detailed and lengthy process that requires adequate planning, the correct construction
team and the implementation of critical safety standards.
•Contracting Road Construction Work
•The initial activity associated with road construction is locating and contracting the construction
company that will build the road. The World Bank website explains that the United States construction
sector operates using a bidding process. Construction companies bid on a construction project and the
most effective bid gets accepted. A contract is then established that combines the client's needs,
contractor obligations, project budget and the length of time to complete the road construction. The goal
is to produce an effective and safe road for a reasonable price, so that both parties as well as the public
benefit.
10. Road Development and Design
•Once the contract is agreed upon, the client and the contractor must develop the construction
plan including the design of the road. The Federal Lands Highway website explains that road
construction must meet federal regulations including pavement requirements, design
specifications and preconstruction procedures. The road development and design process is
critical in order to plan a road that will be cost effective and safe and meet the specific area
needs. The road development plan also has to meet environmental compliance responsibilities
to ensure that the road is a positive and not harmful addition. The final construction plan must
be approved by the city or state in order for the contractor to obtain the necessary building
permits and start the construction of the road.
•Work Zone Safety Requirements
•The U.S. Department of Transportation and the Federal Highway Administration (FHWA) have
developed work zone safety requirements for road construction sites. The FHWA website
explains that the National Highway Work Zone Safety Program was designed and
implemented in order to reduce the number of fatalities and injuries from crashes in work
zones. Construction contractors must review the safety guide and implement the necessary
safety procedures including the placement of concrete barriers, the installation of informative
signs, the use of flashing arrows and the application of rumble sticks. Construction zones are
also required to have significantly reduced speed limits in order to protect motorists,
construction workers and pedestrians.
11. 6:Road CompactiTechniques
Rollers and vibrator equipment consolidate soil in the road bed.
Soil compaction maximizes the soil density under a construction site. The process eliminates excess
moisture and void spaces in the soil. It increases the load-bearing capacity of the soil to minimize shifting
or differential settlement. Compaction provides stability and reduces water seepage, swelling and
contraction. The reduction in water absorption helps prevent and minimize free-thaw conditions that can
cause cracking and crumbling of construction materials during the winter.
•Types of Compaction
•Compaction Techniques and Moisture
•Compaction Machine
•Rammers and Vibratory Plates
•Rollers
12. 7:Road Construction Technology
Road construction technology facilitates the engineering of a road's grade and density.
The technologies involved in road construction encompass many aspects of civil engineering and design. In addition to the
traditional methods of creating roadways using conventional materials, emerging technologies are increasingly incorporating
ecologically-friendly building techniques and innovative approaches to infrastructure formation, according to Environmental
Construction Technologies.
•Rural
•Technologies utilized in rural road planning include the mechanical methods used in designing, grading and paving,
such as scrapers, bulldozers, excavators and vibratory compactors. According to the International Labour
Organization, approaching roadway construction in this manner prompts higher levels of employment and increased
accessibility to basic goods and services for economically challenged peoples.
Soil Stabilization
•Although not a new technology, soil stabilization and road remediation play an integral part in the composition and
management of roads.
13. 8:Disadvantages of Road Construction on Soil
Road construction requires compacting the soil, which is one of the worst things you can do to it.
Most roads are built on deep soil. For a long-lasting and stable road, the soil must be prepared properly. Soil has
many different properties, depending on what kind of soil it is.
•Compaction
•Soil in its natural state is loose and by definition unconsolidated. To build a road, the soil must be compacted
so that it can support the weight of numbers of heavy vehicles. Compacting a soil crushes the soil structure
together and minimizes the amount of pore space.
Natural Use
•After a soil is converted to supporting a road, it is very difficult for it to ever return to its natural state. The
compaction necessary to build the road and the subsequent compaction of the soil by vehicles makes it highly
infertile.
Erosion
•Compacted soils are more easily eroded. Erosion occurs on soils that do not allow water to enter quickly
enough. As water builds up on the surface of a hard-compacted soil, it begins to flow downhill. Depending on
the gradient, the water will pick up speed. The faster the water moves, the more deeply it can cut into the soil.
Groundwater
•Building a road on soil has the disadvantage of reducing the amount of water that can flow through the area
where the road is locate.
14. 9:Road Construction Procedures
•Mapping
•Before construction ever begins, extensive mapping takes place. Surveyors map the entire area to pinpoint where the
new road will sit. Once complete, adjacent homes are mapped and if necessary, bought out through the government's
right of eminent domain, which occurs if the property falls within the new road's right-of-way.
Ground Assessment
•Once surveyors have completed mapping the area, they must next assess the ground for road suitability. Workers take
soil samples using a drill rig or hand auger, with a minimum of 25 samples every mile.
Earthwork
•Once the government has completed all the mapping, property acquisition and soil studies, actual groundwork can begin.
Landscaping and Paving
•Workers place blue stakes every 100 feet and begin to landscape the ground to meet the pre-mapped elevation
benchmarks. With the "blue tops" on the surface, contractors perform a final touch to the dirt road.
Finishing Touches
•Workers apply paint to the finished road and begin work on slopes and ditch bottoms to try and prevent erosion.
Maintenance
•Over time, the new road will experience damage due to weather and use. Chips will develop in the pavement from
freezing water, encroaching plants, snow chains and more.
15. 14:Road Construction Safety Checklist
Road Construction Safety Checklist
Every road construction site is different. However, there are rudimentary safety rules which apply to all sites, in
place to maintain the health and safety of both construction personnel and the public.
•Protective Wear
•On road construction sites, protective gear such as hard hats, reflective vests and steel capped boots are
mandatory for all staff and visitors to the site.
Emergency Procedures
•An emergency strategy is a crucial part of the safety of a road construction site.
Hazard Identification
•There are a multitude of hazards which can threaten the safety of site personnel, such as electrical,
mechanical, trip or fall hazards.
Security
•For safety reasons, is it essential to monitor who is on site at all times. Permanent staff are required to
undergo an induction process which explains the rules and responsibilities on site, after which they are
issued a security pass.
16. 15:Safety Checklist for Construction
Hard hats protect from many construction injuries.
Construction workers are exposed to job hazards on a daily basis. It's important for companies to follow a
safety checklist. Various types of injuries can result from improper safety on construction commercial and
residential construction sites. Construction job-related accidents can be significantly reduced with the proper
safety equipment and with safety checklists. According to the Occupational Safety and Health Administration,
the fatality rate for construction-related injuries is one of the highest in industry.
