In addition to the minimum and maximum thickness requirements, the following restrictions are placed on fine mixes when used as a structural course: Type SP-9.5 - Limited to the final (top) structural layer, one layer only.
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Where Type S Asphalt Concrete is specified in the Contract, if approved by the Engineer, Type S-III Asphalt Concrete may be selected as an alternate for the final surface when no friction course is specified, and as the final layer of structural course prior to the friction course.
S-1.1. DESCRIPTION. This work consists of the construction of a Porous Hot Mix Asphalt Wearing Course Mixture (Porous HMA). The work shall be in accordance with these specifications and shall conform to the lines, grades, thicknesses, and typical cross-sections shown on the plans or established by the Engineer.
When pneumatic or vibratory roller is used, the maximum lift thickness that can be compacted is almost unlimited. Generally, lift thicknesses are limited to 6 or 8 inches. Proper placement becomes a problem in lifts thicker than 6 or 8 inches.
Superpave defines nominal maximum aggregate size as “one sieve size larger than the first sieve to retain more than 10 percent of the material” (Roberts et al., 1996).
The Type B Specification has only a Specification for 50% breakdown at 500 revolutions. This Measure of durability is essential for pavement stability. At Graniterock, our crushed granite is easily type A. Many other indicators of Aggregate and HMA quality are distinguished this way.
Asphalt Paving ‐ 19mm Binder Course 19mm Binder Course is applied in one layer, is as strong as regular base and has a sufficient amount of liquid asphalt to roll into a very durable surface. The difference is that the texture is coarser than 9.5mm Wearing Course.
145 lb/ft3Standard density for asphalt is 145 lb/ft3 (2322 kg/m3). Multiply the volume by the density (in the same units) to get the weight.
Asphalt laying can be done during light rain but is most successful when completed during warm, dry weather. It is an oily material that repels water. However, one type of asphalt cools too quickly in chilly rain and another hardens slowly or is damaged by excess water.
Multiply Volume by the Density To determine how much asphalt you will need for the project, multiply the area's cubic feet measurement by 148 PCF. For example, if the area is 40 cubic feet, then the formula is: 40 cubic feet x 148 PCF = 5,920 pounds of asphalt mix.
The grading or size distribution of aggregate is an important characteristic because it determines the paste requirement for workable concrete. This paste requirement is the factor controlling the cost, since cement is the most expensive component.Oct 25, 2019
Aggregate gradation and size range influence the strength and stiffness characteristics of the mixture, permeability, asphalt content, economy, workability, and skid resistance.
Gap grading of the aggregates results in lower requirement of water content, and hence lower water-cement ratio, and permits a higher aggregate-cement ratio to achieve the same workability as its continuously graded counterpart with equal cement content and equal maximum size of coarse aggregate.