HDOT does use an open-graded untreated aggregateĭrainage purposes. HDOTĭoes have a specification for ATPB, but it is rarely used. Or portland cement concrete to assist in drainage.įriction courses (OGFCs) are not typically used by either the Hawai'i Department of Transportation (HDOT) or the Counties. A pavement base layer sometimes used under dense-graded HMA, SMA Permeable pavement is a commonly used low impact development (LID) technique.īases (ATPB). Usually the goal is to allow the water to infiltrate into the ground underneath the pavement. An entire pavement structure that is designed to allow water to pass through the pavement. A thin surfacing layer used to improve safety by (1) improving visibility from reduced tire splash and spray in wet weather, (2) reducing hydroplaning risk by reducing water sheet flow across the pavement surface in wet weather, and (3) improved skid resistance. The three most typical uses for open-graded mixesĬourse (OGFC). Only crushed stone (or gravel) and a small percentage of Unlike dense-graded mixes and SMA, an open-graded HMA mixture
#Higher type mix base widening asphalt iowa dot trial#
The State of Hawai'i has done two SMA trial projects: one on the Big Island at Hilo Harbor in 2001, and one on the Moanalua Freeway in 2004. The amount of asphalt binder used in the mix and Mineral fillers and additives are used to minimizeĪsphalt binder drain-down during construction, increase Noise (due to a coarser surface texture) and less severe reflectiveĬracking.
Other reported SMA benefits include wet weatherįriction (due to a coarser surface texture), lower tire SMA, has been used with success in the U.S. In the right situations it is cost-effectiveīecause of its increased rut resistance and improved durability. More aggregate stockpiles (and sometimes more waste in creating the gradation from available stockpiles), higher asphalt content, modified asphaltīinder and fibers. SMA is generally more expensive than a typical dense-graded HMAīecause it requires more durable aggregates, Since aggregates do not deformĪs much as asphalt binder under load, this stone-on-stone The mix design goal is to create stone-on-stone contact Stone mastic asphalt, is a gap-graded HMA Stone matrix asphalt (SMA), sometimes called Particulars about dense-graded HMA are coveredīy the rest of this Guide. Suitable for all pavement layers and forĪll traffic conditions. Dense-graded mixes are used extensivelyįigure 1: Dense-graded HMA cut-away view. Dense-graded mixes are generallyĬan further be classified as either fine-graded or coarse-graded.įine-graded mixes have more fine and sand sized particles
ReclaimedĪsphalt pavement (RAP) is generally consideredĪ material within HMA, while forms of in-placeĬonsidered separately. Treatments and are therefore covered in the Maintenance & Rehabilitation section. Typically agencies consider other types of asphalt-based pavement Warm mix aspshalt (WMA) is a variant of HMA that is produced at lower temperatures. In this Guide) and includes traditional dense-graded mixesĪs well as stone matrix asphalt (SMA) and various open-graded HMAs. For clarity, this Guide makesĪ conscious effort to consistently refer to this material asĭistinguished by its design and production methods (as described Names such as hot mix, asphalt concrete (AC or ACP), asphalt,īlacktop or bitumen.
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