Fatigue-resistant flexible road structure

A fatigue-resistant flexible road structure comprising:

• one or more sub-base structural support layers positioned over a compacted earth foundation, at least one of the one or more sub-base structural support layers being an elastic sub-base layer including aggregate, filler, binder, and recycled tire rubber, the recycled tire rubber being included in an amount of 3% to 5% by weight of the sum of aggregate, filler, and rubber, the elastic sub-base layer having a fatigue life at least 25 percent greater than a non-elastic sub-base layer without recycled rubber and the elastic sub-base layer having a modulus of elasticity at least 25 percent lower than a non-elastic sub-base layer without recycled rubber;
• one or more load-distributing base layers positioned over the one or more sub-base structural support layers, the one or more load-distributing base layers including at least aggregate, filler, and binder, and having an air void content of approximately 3 to 5 percent;
• one or more surface layers positioned above the one or more load-distributing base layers, the one or more surface layers including at least one vehicle-contacting layer configured to prevent surface water from entering the base and sub-base layers, the one or more surface layers having an air void content greater than the air void content of the one or more load-distributing base layers.