IAPA :: Asphalt FAQs

Stone-matrix asphalt (SMA) is a gap-graded asphalt pavement designed to improve rut resistance and durability through the use of a stable stone-on-stone skeleton held together by a rich mixture of asphalt cement, along with stabilizing agents such as fibers and/or asphalt modifiers.

HMA Mix Type Selection

Dense Graded Hot Mix Asphalt (Method) Texas Asphalt Pavement Alliance Item 341 Dense Graded Hot Mix Asphalt (QC/QA) Texas Asphalt Pavement Alliance Item 341 – Dense Grade HMA ... – Gradation is not as "gap graded" as an SMA mixture – More susceptible to cracking and water infiltration than SMA mixtures . Texas Asphalt Pavement

Types of Flexible Asphalt Pavements | G3 Quality

Jan 14, 2021· Rubberized Hot Mix Asphalt-Gap-graded, or RHMA-G, is a mixture with a high coarse aggregate content with a portion of aggregates missing from the middle of the gradation band – hence the "Gap". This gap is intended to provide sufficient space in the mixture for rubber modified binder while keeping the stone on stone contact for rut ...

2019 APAM Conference Hot Mix Asphalt (HMA) Update

•Stone Matrix Asphalt (Gap-Graded Superpave) Fine Texture Pavement Milling •FUSP 501JJ •Use Statement: •Use on all trunkline, one course, non-freeway mill and resurface projects. •Where the integrity of the existing pavement makes it suitable to allow

Rubberized Hot Mix Asphalt (RHMA) Mix Design

Oct 28, 2016· Aggregate Gradation • Uses a gap-graded aggregate gradation • Limits of proposed gradation tolerances much tighter • For gap graded and open graded mixes - 40% higher binder content (7.5 -8.5% by total weight) • Use of asphalt rubber allows for …

02 - Aggregate Gradation

Gap-Graded Aggregate 0 20 40 60 80 100 100 10 1 0.1 0.01 Percent Passing Opening Size (mm) 1½" ¾" 3/ 8" 4 8 16 30 50 100 200 Open graded gravel Open graded sand Gap graded blend Missing sizes. CIVL 3137 20 Gap-Graded Aggregate Wide range of sizes Missing middle sizes No grain-to-grain contact Moderate void content

Draft TRH8 DESIGN AND USE OF HOT -MIX ASPHALT IN …

The various types ofhot-mix asphalt (gap -, semi-gap- and continuously-graded asphalt, dense bitumen macadam and open-graded asphalt) are reviewed. Suggestions are made as to the most effective selection of a particular type of asphalt for a specific situation, consideration being given to functions, properties and performance.

Stone Mastic Asphalt - Civil Engineering Portal - Biggest ...

Stone mastic asphalt (SMA) is a stone-on-stone like skeletal structure of gap graded aggregate, bonded together by mastic, which actually is higher binder content, filler and fiber to reduce the binder drain. This structure improves the strength and the performance of SMA even higher than the dense graded and open graded asphalt mixtures.

Asphalt Products - EAPA

Dense asphalt concrete is often used as the 'basic' surface layer. 2. Asphalt Concrete for very thin layers (AC-TL) "Asphalt for surface courses with a thickness of 20 mm to 30 mm, in which the aggregate particles are generally gap-graded to form a stone to stone contact and …

Milling – Midstate Companies

The process yields a crushed, somewhat gap-graded RAP (reclaimed asphalt pavement) material (95% passing a 2-inch sieve is typical) that can be reused as base or in hot or cold asphalt mixes. It makes sense for a range of applications, the most common being the removal and replacement of aged and cracked courses, restoring curb-reveal for oft ...

901 AGGREGATES - SHA MediaWiki

Jun 16, 2020· gap graded stone matrix asphalt mix - 9.5mm 100 100 75–90 30–50 20–30 — — — — 8–13 gap graded stone matrix asphalt mix -12.5mm 100 90–99 70–85 28–40 18–30 — — — — 8–11 gap graded stone matrix asphalt mix -19.0mm 100 82–88 60 max 22–30

Mix Types – Pavement Interactive

Stone matrix asphalt (SMA), sometimes called stone mastic asphalt, is a gap-graded HMA originally developed in Europe to maximize rutting resistance and durability. The mix design goal is to create stone-on-stone contact within the mixture. Since aggregates do not deform as much as asphalt binder under load, this stone-on-stone contact greatly ...

(PDF) Resilient modulus of hot-mix asphalt gap graded with ...

The composition of aggregate with gap graded specifications of the Bina Marga HRS-WC 2010 (revision 3) was obtained through a screening process by using sieves to obtain the weight % of each filter size. All asphalt mixture samples used in this study were included into gap graded aggregate.

HMA Mix Types | Washington Asphalt Pavement Association

Stone matrix asphalt (SMA), sometimes called stone mastic asphalt, is a gap-graded HMA originally developed in Europe to maximize rutting resistance and durability (Figure 2 and 3). The mix goal is to create stone-on-stone contact.

What Is Asphalt Concrete | Types & How It Is Made | M&C

According to the different gradation of mineral aggregate, asphalt concrete can be divided into 3 types: dense graded asphalt concrete, open graded asphalt concrete and gap graded asphalt concrete. Among them, the dense graded macadam mixture of hot mixing and hot paving is durable, high strength and good integrity, which is the most widely ...

Asphalt Rubber Hot Mix-Gap Graded (ARHM-GG) …

Rubberized asphalt is a hot-mixed asphalt pavement containing crumb rubber. The crumb rubber serves as a "modifier" of the liquid asphalt. It's addition gives the liquid asphalt greater viscosity (resistance to flow) and improves other properties which …

Hot Rolled Asphalt

Asphalt? • Essentially a gap graded material • Sand, Bitumen, Pen 50 filler and stone floating • On which 20mm Bitumen coated chippings are applied to the surface – before rolling • High stone content Asphalt is occasionally specified • Sand Carpet

Asphalt Concrete – Asphalt Pavement Association of New Mexico

Gap Graded Asphalt Technology – Gap-graded mixes use an aggregate gradation with particles ranging from coarse to fine with some intermediate sizes missing or present in small amounts. The gradation curve may have a "flat" region denoting the absence of a particle size or a steep slope denoting small quantities of these intermediate ...

Chapter 10 - Design of Gap-Graded HMA Mixtures | A …

Suggested Citation:"Chapter 10 - Design of Gap-Graded HMA Mixtures."National Academies of Sciences, Engineering, and Medicine. 2011. A Manual for Design of Hot-Mix Asphalt with Commentary.Washington, DC: The National Academies Press. doi: …

HOT MIX ASPHALT PAVEMENT DESIGN GUIDE

Section 904 —Performance graded asphalt bin & HMA Section 915 —Production Plants Section 915.02 —Hot Mix Asphalt Plants TACK COAT A tack coat of asphalt (usually emulsified asphalt) is applied to ensure bond between the existing surface and the asphalt overlay. It should be applied in …

904 PERFORMANCE GRADED ASPHALT BINDERS AND ASPHALT …

Jul 16, 2020· This requirement also applies to 904.05 Gap-Graded Stone Matrix Asphalt (GGSMA). (a) If the PWSL for the three test values falls below 85, take corrective action to bring the PWSL to at least 85. (b) If the PWSL drops below 68, production shall be suspended until corrective action is taken as approved. 904.05 GAP-GRADED STONE MATRIX ASPHALT (GGSMA)

ASPHALT CONCRETE [Types] - KSU

Gap- graded Mix Sand sheet mixes were altered by coarser aggregates, hence a gap occurs. The aim was to increase the stability of the mix (British standards). Gap- graded Mix Advantage: gap-grading allows more voids, thus more binder, making a more durable and less permeable compared to dense-graded mixes. + higher skid-resistance. Gap-graded

WHAT IS GAP GRADED AGGREGATE AND WHAT ARE ITS …

Apr 01, 2014· What is Gap Graded Aggregate? Generally we use well graded aggregate or continuous graded aggregate, which means representation of all the …

Combined Gradation Example - Montana

Zone I, Gap Graded Zone III, WellGraded, 3/4" and finer CF = 62.5% WF = 34.8%. Concrete Aggregate Combined Gradation Example Page 4 of 6 indicates that mixes using high range water reducers that are in Zone II-a have a tendency to segregate. This subzone is generally below the Workability Box.

Bonded Wearing Course Treatment Types

A bonded wearing course (BWC) is a gap graded, ultra thin hot-mix asphalt (HMA) mixture applied over a thick polymer modified asphalt emulsion membrane. The high binder content seals the underlying road thereby protecting it from water infiltration and slows down the aging process.

Lecture 6 Asphalt mix design(1).pdf - Lecture 6 Asphalt ...

Fine Gap Graded Asphalt (FGGA) mix In a fine gap graded asphalt mix, the intermediate size fraction is replaced by finer fractions. It may also contain more filler. Fine gap graded mixes rely for stability on the stiffness of the fine aggregate, filler and binder.

Gap-Graded Aggregate And There Advantages - Civil Knowledges

Gap-Graded Aggregate and There advantages. Gap graded aggregate:- Gap grading is defined as a grading in which one or more intermediate size fractions are absent.On a grading curve, it represents a horizontal line over the range of sizes that are absent.

What are the grades of asphalt?

The gap graded asphalt mixtures will have higher air-voids when compared to dense graded asphalt mixtures. What is concrete pavement? Concrete Pavement—In its most basic form, a concrete pavement is an extruded slab of concrete made from cement, aggregate, sand, and water.

Open Graded Asphalt Design Guide - AfPA

OG is a gap graded mix with intermediate sized and fine aggregate fractions omitted from the grading while dense-graded asphalt has a more continuous grading. Air voids are more inter-connectedin OG compared to dense-graded mixeswhere the voids are often occluded. This is …

SPECIFICATIONS FOR DENSE BITUMINOUS MACADAM AND …

Dense graded bituminous mixes such as binder and wearing courses are usually laid on a previously prepared bituminous layer. Binder course is the intermediate layer between bituminous base course and bituminous wearing course. Three different Specifications for dense graded bituminous mixes are available for use for airfield pavements.