Asphalt roadAsphalt is among the most flexible materials used for pavements. It is a mixture of sand, rough aggregate stone, asphalt cement and fine aggregate. Depending on the temperature used in manufacturing, it is classified as warm, hot or cold mix asphalt.

Contractors like Auckland Asphalt Repairs usually use hot mix asphalt (HMA) for concrete kerbs, driveways, tennis courts, roads, parking lots and racetracks. Each job requires a different type of HMA. Here are the classifications of HMA available for your project:

Dense-graded mixes

This HMA is classified according to its aggregate size and mainly falls into two subsections: fine and coarse-graded mixes. A fine-graded dense-grade mix has a higher small stone and sand percentage than the coarse-graded mix. Dense-graded mixes are appropriate for all traffic settings and are suitable for levelling, patching and friction jobs.

Stone matrix asphalt

This HMA has gaps that are deliberately implemented to avert rutting and sustain durability. It is more costly than dense-graded mixes because it requires modified asphalt binders, a higher content of asphalt and more long-lasting aggregates. It is typically used on high volume roads and large projects because of its inhibiting cost.

Open-grade mixes

This HMA is the most permeable among the three mixes because it is made of fine-grade sand and crushed stones. Open-grade mixes are classified into open-grade friction course (OGFC) and asphalt treated permeable base (ATPB) mixes. OGFC typically has a minimum of 15% air void and is used for surface layers since it prevents water splashes from vehicles in wet conditions. ATPB is only used under stone matrix asphalt, concrete or dense-grade mixes for drainage.

HMA is a cost-effective and durable option for all asphalt projects. HMA repairs are the finest way to permanently repair potholes and offer a longer lasting solution than cold mixes. Asphalt paving is costly, and a shoddy job can lead to pooling of water around your building’s foundation. Ensure you hire a qualified asphalt contractor for your project.