Contents

• Introduction
• Asphalt
• Ground Cover
• Refractory Concretes
• Shotcrete
• Storm Water Management

Related Literature

Asphalt Advantages

• Safety
• Cost-effectiveness
• Lower Transport & Construction Costs

Safety

The superior skid resistance (wet or dry) of road surfaces made with LWA increases safety.

This high skid resistance is maintained throughout the road's service life because of the aggregate's rough micro surface texture. Pavements made with normal weight aggregates (especially those using limestones, dolomites and gravel) may polish or become slick under the action of traffic and lose a large percentage of their skid resistance. Lightweight aggregates do not polish as they wear. LWA pavement maintains its high skid resistance because under wear, fresh interior cells with rough ceramic-like edges are continually exposed.

All tires sold in the United States are certified for friction compliance on a hot-mix LWA pavement built for the Federal Highway Safety Administration in San Angelo, Texas. Lightweight hot mix was chosen for its constant high friction and durability.

Cost-effectiveness

LWA's unique and superior bonding capabilities with asphalt extend roadway service life.

 When bonded to the asphalt, lightweight aggregate presents a tough, durable pavement that holds up well under traffic and outlasts most pavements made with normal weight aggregate. LWA has minimal dust unlike normal weight aggregate that is often coated with dust that prevents uniform bonding and creates public complaints during application. Lightweight aggregates consistently pass Los Angeles Abrasion Requirements as well as other quality tests. LWA also shows superior "freeze-thaw" resistance and durability to de-icing salt corrosion. If snow plow damage occurs, LWA is far more resistant to being stripped out than normal weight aggregate. Lightweight aggregate is the proven solution for cost-sensitive highway and road departments. LWA offers lower direct and indirect costs over the service life of the road and is the reason more state and local transportation departments are specifying LWA.

Lower Transport and Construction Costs

• Material haul costs are reduced because LWA weighs about half that of normal weight aggregate thus allowing for a much larger volume of material per truck load and less overall tonnage to be hauled.  Contractors consistently report fewer breakdowns because of less equipment wear and tear.
• LWA is much easier to hand-broadcast.
•  Chip seal projects are safer because there are fewer and less dangerous flying particles caused by passing vehicles. Windshield damage claims are practically eliminated.
• Brooming or vacuuming excess chips from chip seal projects is much easier with LWA
• Lightweight aggregate is easily pre-wetted and will hold moisture for days in a stockpile providing an almost dust-free placement -a plus when emulsions are used with chip seals.
• Lightweight aggregate is readily available throughout the U.S., Canada and much of the world.
• The contractor can use the same machinery and equipment as with normal weight aggregate with one exception: only use pneumatic rubber-tire rollers with chip seal projects (no steel-wheel rollers).