One of the most useful materials that we use today that you probably see every day but often ignore is asphalt. The very surface of the roads that our vehicles go over every day is made of Asphalt. This material is actually quite interesting. Not only is it very durable but it is also quite cost effective and can even by recycled allowing more money to be saved. The use of asphalt actually provides a number benefits including smoother roads, safer driving, and environmental friendliness.
The primary use of asphalt is for road paving, but there are different mixtures of asphalt that have different properties and each is better suited for certain areas like porous asphalt for areas that have constant rain or gritty asphalt to help avoid the danger of skidding in case a car needs to brake and stop. Today, we are going to take a look at different mixtures of asphalt based on how they are made.
1.) Hot mix asphalt concrete – Also known as HMAC for short, this type of asphalt is made with the heating the binder of the asphalt to be able to lessen its viscosity. In addition the aggregate is dried out so that any moisture is removed before they are mixed. The mixing process is done together both asphalt and aggregate and they are mixed in a temp of 330 degrees F for asphalt that has been polymer modified and 300 degrees for virgin asphalt while asphalt cement is mixed at 200 degrees. This type of Asphalt is usually used on airfield, major highways, and even racetracks.
2.) Warm mix asphalt concrete – Also known as WMA for short, this type of asphalt mixture gets added with either some wax, emulsion, zeolites, or water into the binder before the asphalt is mixed. Because of this, the asphalt can be mixed in a lower temperature thus more fossil fuel is saved and less CO2 is released making this asphalt mixture more environmentally friendly. The production of WMA asphalt has increased quite significantly recently.
3.) Cut-back asphalt concrete – This type of asphalt mixture is made by dissolving the asphalt binder in some kerosene or another type of light petroleum before the asphalt is mixed with the aggregate. Because the asphalt binder is dissolved, it becomes less viscous making it much easier to work with and compact. Once the asphalt mixture is laid onto the road, the kerosene or petrol evaporates.
4.) Cold mix asphalt concrete – The process of making this type of asphalt is much similar to cut-back asphalt. In this Asphalt mixture, the asphalt is emulsified with a mixture of soap and water before it is mixed with the aggregate. Just like cut back asphalt the asphalt in the emulsion is much easier to work with and also easier to compact. As the asphalt is laid out and sets, it starts to take on the properties cooled HMAC. This type of asphalt mixture is usually used to patch up roads and laid on areas which aren’t as used or have less traffic.