We park on asphalt parking lots and drive on asphalt highways and roads every day, but how often do we think about the equipment required to build them?
Let’s take a look at the equipment needed to construct these asphalt surfaces and how it’s used.
Milling Machines
Milling machines are used to remove the top layer of an existing pavement before a new asphalt layer is laid. Milling can remove only the surface or the entire depth of the pavement, known as full-depth removal. Paved areas may need to be milled to level the surface or repair the damaged layer.
A milling machine, also called a cold planer, is a heavy-duty piece of equipment with a large rotating drum. Cutters inside the drum rotate and cut up the existing asphalt surface to the required depth. A vacuum sucks up the milled material where it’s loaded onto a conveyer belt attached to the milling machine. Water is typically applied to the drum during the milling process to reduce the machine’s extreme heat and minimize the dust milling causes. A dump truck moves alongside the milling machine to collect the material as it’s removed. This method saves both time and effort. The milled asphalt is recycled and used in other projects.
Sweepers
After the asphalt pavement has been milled, a sweeper is used to clean the surface. Large particles of debris can cause uneven compaction of the asphalt. Even small amounts of dust and debris left on the ground can prevent the new asphalt from bonding properly with the surface below. It’s also necessary to sweep after milling to prevent small rocks from hitting the oncoming traffic and damaging vehicles’ windshields.
Dump Trucks
Most asphalt paving job sites use several types of dump trucks to haul asphalt from the plant to the job site. Here are some of the most common ones:
Bottom Dump – Bottom dump trucks are also known as belly dump trucks because they release their load from underneath instead of spilling it out like standard dump trucks. Sloped internal walls guide the asphalt out through opened gates.
End Dump – These trucks raise the front end and let the asphalt slide down the bottom of the bed and out the back through a tailgate. End dump trucks are popular because they are versatile and easy to maneuver.
Live Bottom – Live bottom, or flo-boy, dump trucks have a conveyor system at the bottom of their bed to unload their payload. Hot Mix Asphalt (HMA) is discharged out of the trucks’ bed without raising the bed. These trucks are more expensive to operate and maintain because of the conveyor system, but they can decrease segregation problems because the HMA is moved out in large piles. They can also eliminate some potential types of truck bed paver contact because the bed isn’t raised during the unloading process.
Pavement Design and Testing
ParklandGEO can provide pavement related from preliminary and detailed design through to post-construction pavement management, maintenance and rehabilitation. We offer pavement related design recommendations as part of many of our geotechnical engineering projects as well as the following specialized pavement services:
CCIL Certified aggregate lab (Type D Advanced)
CCIL Certified technicians for testing
Pavement Design
Pavement Management
Failure Investigations
Superpave mix designs and aggregate testing
Construction testing for pavement materials and roads
ParklandGEO usually undertakes pavement design as part of municipal infrastructure or industrial/ residential land development projects; and provides designs based on pavement assessments for reconstruction/ upgrade projects on existing roadways. We have provided designs for flexible asphalt concrete pavements (ACP), rigid Portland cement concrete (PCC) pavements, roller compacted concrete (RCC) pavements, interlocking paver block/ slab pavements and granular pavements including pads and resource roads on muskeg.
ParklandGEO has considerable experience undertaking pavement assessment and failure investigations on industrial, urban road and highway project sites. In Western Canada most hard surface roads are constructed with ACP. We are very familiar with Pavement Management System evaluations for ACP, including structural assessments based on deflection testing, visual condition assessments, ride comfort indexes, etc. While we subcontract major deflection testing projects (i.e. FWD or Dynaflect), we have the ability to undertake localized pavement deflection testing for smaller projects using Benkelman Beam equipment. We have experience using a number of subgrade, base and pavement reinforcement options including: geotextiles, geo-grids, geo-cells, cement stabilized subgrade, cement stabilized base (soil cement), Full Depth Reclamation (foamed asphalt base), Deep Asphalt Base Replacement, ACP layers with Polymer Modified Performance Grade Asphalt Cement and composite pavements including PCC pavement layers. Our innovative knowledge in pavement technology helps us to provide our rehabilitation project clients with optimized pavement designs and reduced life cycle costs.
Types of Asphalt
Large potholes can ruin anyone’s day. Not only are they a nuisance to your car (and your alignment), but they also create a safety hazard for pedestrians. Whether you need to clear up a pothole in a street, a driveway, or a parking lot, asphalt is the material that you will need in order to smooth your way.
When working with asphalt, it is important to know the different varieties that are available. There are three main types of asphalt: Hot Asphalt, MC Cold Mix, and UPM. There are also different varieties of these asphalts for summer and winter use. Below is a brief overview of each type of asphalt.
Hot Asphalt is the type of asphalt that you mostly see when driving past a construction crew. Use mostly for paving and patching, Hot Asphalt, as its name suggest, is easiest to work with when the temperature of the asphalt is high. Hot Asphalt is a permanent solution to a problem, but must be used almost immediately after purchasing. As the asphalt cools, it becomes increasingly difficult to work with, and once completely cool, it hardens like a rock.
MC Cold Mix is asphalt that can be used as a temporary fix. Since the asphalt is used at cold temperatures, it is slow to cure and best used in areas that have little to no traffic.
UPM is also a cold mix asphalt, but unlike MC Cold Mix, it can be used as a permanent fix to any asphalt or concrete problem, Designed to work in any weather condition, UPM can be used to fix both wet and dry holes, allowing you to make any repair in any situation. Once that asphalt has been compacted, it is immediately ready to be tread upon. Learn more about the benefits of UPM.
These three different types of asphalt offer good solutions to asphalt problems that you might have in your home or business. By knowing the differences, you can make sure you pick the right one for your situation.
Applications & Uses of Bitumen in Construction
According to IS: 334-1951, bitumen is a non-crystalline solid or viscous material having adhesive properties, derived from petroleum either by natural or refinery process. During this process, smaller amounts of crude oil like kerosene, fuel oil, spirit and lubricating oil evaporate.
Bituminous materials were used for the construction of roads, preserving timber and for waterproofing stone walls. Nowadays, they are extensively used for surfacing of road and airport pavements.
Bitumen emulsion: It is a mixture of bitumen, water and an emulsifying agent, which is in liquid form formed in aqueous medium and stabilizing agents. There are three varieties of bitumen emulsion, namely, slow setting (SS), medium setting (MS) and rapid setting (RS) depending upon the stability provided by the emulsifying agent.
It can be easily applied at ambient temperature, merely mixing it with aggregates for road works starts the binding process. The colour change from brown to black indicates the binding and can be used for road repairs and soil stabilization.
Blown bitumen: It is produced by heating until it becomes a liquid and then passing air under pressure by which all the volatile compounds in it can be forced out. It is in solid form and has a high softening point so that if exposed directly to the sunlight for a long time, it does not melt.
How to Conduct a Soil pH Test at Home
As a home gardener, it's important to test soil pH because certain plants have specific pH requirements and won't thrive unless the soil pH falls within a particular range. pH measures the level of acidity in the soil and it affects a plant’s ability to absorb nutrients. If the soil pH level falls outside of a plant's recommended range, all the plant food and fertilizer in the world won’t help -- the plants can’t absorb nutrients.
Technically speaking, a soil pH test measures how many hydrogen ions are in the soil. On a scale of 1 to 14, a pH less than 7.0 is acidic, 7.0 is neutral, and anything higher than 7.0 is alkaline. Acidic or alkaline soil isn't necessarily bad; it all depends on the plants you're growing.1 Most plants can adapt to soil pH ranges from 6 to 7.5, but some plants have distinct requirements. For instance, blueberries require acidic soil in the range of 4.5 to 5.5 to produce berries while lavender tends to do best in alkaline soil about 8.0.
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