How Roads are Made - Types of Road
Have you ever wondered what roads are made of? Not all roads are constructed from the same materials. You might be surprised to know the fact that before the 1920’s the roads in US and Canada were made of dirt. The dirt was pressed evenly and the vegetation and stones or rocks were removed in between. But unfortunately it was difficult to maintain as the compactness of the surface of the road can be easily disturbed by strong rains. Today’s transport like trucks, buses are a lot more bulkier if you compared to the carts and carriages from the olden days, and therefore, in order to make more strong and solid roads, the technique of road construction and materials needed have undergone a big change. Depending upon the materials we use, roads can be divided into several types
Chip Seal Road
Chip seal is one of the most common types of road used in Canada, Australia, USA and New Zealand. This road is ideal for less busy streets such as industrial streets or residential roads, highways or country roads. In order to make this type of road, they pour a layer of tar onto a road before a layer of fine gravel is pressed on it. After that, a steamroller will proceed to drive over the gravels, setting them into the tar. The excess of gravel would be brushed aside by the labors so that they wont cause obstruction. When we are driving on newly sealed Chip-seal roads, we should drive very carefully and slowly as some loose gravel can hit our windscreen. Chip seal are probably the most popular roads in the world, this is because they are constructed very easily and rapidly
Asphalt roads are now considered as a new development and they have become widely used in the last decade or so. Asphalt roads are also very strong that they do not wear and tear easily despite of hard and bulky transportation. Therefore they are suitable used for busy roads, urban commercial areas, the main streets of a town, and places where vehicles stop and start a lot. Asphalt roads are made by mixing gravel and tar seal. It is mixed beforehand, and the whole mixture is then poured onto the road. After that, it is smoothed and left to dry. The disadvantage of using this type of road is that it loses grip when wet
Concrete, Gravel and Dirt Roads
Roads that are made of concrete are stronger than the ones made from asphalt, but they take longer time for construction. Concrete roads are usually used for heavy traffic. Concrete usually last longer than asphalt but it can also crack and chip if not reinforced with rebar.
In olden cities, some of the roads were made from smooth stones. Bricklayers would have placed the pavers over a prepared bed, grout or concrete were then used to hold the individual stones in place. But when the use of asphalt became popular, many of those brick and stone roads were simply paved over.
Gravel roads are often constructed in rural areas where there is fewer traffic. This type of road is very cheap to make and only need little maintenance. Fine gravel is poured evenly on the surface of the ground before being pressed until the whole gravel adjusts to make a uniform path.
Roads that made from dirt can often be found as pathways in forests and bushes. These roads are not suitable for 4 wheelers especially during wet season because the dirt will turn into mud. This type of road is recommended only for walking, horse ride, or going on a bicycle or tricycle.