I know some asphalt is rubberized... And I kno the reasons... But I cant figure out why they would use concrete and when they decide to use it. It makes for a rough ride... No one likes it
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Concrete roads are superior to asphalt road. They have a service life 4 times that of asphalt. They have a much lower rolling resistance leading to a 15% to 20% fuel savings for the motorist. Concrete is nearly impervious to oil and fuel spill damage, and has a better weathering profile. Bitumen processing produces a butt load of VOC's. Bitumen is a limited resource; whereas, limestone is abundant.
Asphalt is considerably cheaper.
The standard for asphalt¹ road construction is:
The sub-grade: reshaped and compacted native substrate with all the organic layers removed.
A permeable membrane²: allows water to drain from the sub-base while limiting erosion.
The sub-base: compacted gravel aggregate.
The base course: the load bering course of asphalt.
The binder course³: a load spreading course of asphalt.
The surface course: the smooth, wearing course.
Notes:
¹ New asphalt roads are not underlain with concrete. The materials have dissimilar rates of thermal expansion and the concrete wins that battle every time, shortening the service life of the overlying asphalt courses. Only use asphalt over concrete if your brother is in charge of approving contracts for repaving.
² Not needed in dry climates.
³ Not used in some types of high stability construction methods.
Asphalt is considerably cheaper.
The standard for asphalt¹ road construction is:
The sub-grade: reshaped and compacted native substrate with all the organic layers removed.
A permeable membrane²: allows water to drain from the sub-base while limiting erosion.
The sub-base: compacted gravel aggregate.
The base course: the load bering course of asphalt.
The binder course³: a load spreading course of asphalt.
The surface course: the smooth, wearing course.
Notes:
¹ New asphalt roads are not underlain with concrete. The materials have dissimilar rates of thermal expansion and the concrete wins that battle every time, shortening the service life of the overlying asphalt courses. Only use asphalt over concrete if your brother is in charge of approving contracts for repaving.
² Not needed in dry climates.
³ Not used in some types of high stability construction methods.
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I dare you to show me ONE road that is entirely made of asphalt. Asphalt is usually used on top of concrete. Concrete has tensile strength and stress capacity that asphalt completely lacks.