Hot mix asphalt (HMA) is known by many different names, such as hot mix, asphalt concrete, asphalt or blacktop. It is a combination of stone, sand or gravel bound together by asphalt cement. After it is mixed at a high temperature, laid and compacted, the result is an improved driving surface for the traveling public.

What are the components of hot mix asphalt?

Hot Mix Asphalt (HMA) is a combination of approximately 95% stone, sand, or gravel bound together by asphalt cement, a product of crude oil. Asphalt cement is heated aggregate, combined, and mixed with the aggregate at an HMA facility.

What are the ingredients of asphalt?

asphalt, black or brown petroleum-like material that has a consistency varying from viscous liquid to glassy solid. It is obtained either as a residue from the distillation of petroleum or from natural deposits. Asphalt consists of compounds of hydrogen and carbon with minor proportions of nitrogen, sulfur, and oxygen.

What is the difference between hot and cold mix asphalt?

Strength – Hot mix asphalt is the most durable grade of paving asphalt, which is why it’s used for high traffic roads and highways. Cold mix asphalt isn’t strong enough for regular vehicle traffic. Bend but Not Break – Asphalt is more flexible than it’s paving counterpart concrete.

What is mixture of asphalt?

Asphalt mixtures: Asphalt is a mix of sand, gravel, broken stones, soft materials, and asphalt. In Marshall’s Standard Test^* for designing asphalt mixtures, it was found that the percentage of asphalt required can be reduced as the density of the mixture increases.

How do you make hot asphalt mix?

Then it's time to pump in hot asphalt cement oil refineries make asphalt cement. From what's left over after they've processed crude oil the paving mix contains about 5% asphalt cement.

What is asphalt binder made of?

In its most common form, asphalt binder is simply the residue from petroleum refining. To achieve the necessary properties for paving purposes, binder must be produced from a carefully chosen crude oil blend, and processed to an appropriate grade.

Is there cement in asphalt?

First, both asphalt and concrete have a gravel base. They are both made with stone and sand. The primary difference involves their adhesive materials. Asphalt is petroleum-based while concrete is made of cement.

Does asphalt have oil in it?

Asphalt occurs naturally in a few places in the world, but most of the asphalt used today for paving comes from petroleum crude oil. Asphalt is the heaviest part of the crude—what’s left after all the volatile, light fractions are distilled off for products such as gasoline.

Is cement used in asphalt?

Asphalt concrete is a combination of two primary ingredients: (i) aggregate and (ii) asphalt cement. Typically, the aggregate constitutes 90–95% (w/w) of the total mixture and the asphalt cement (asphalt binder) constitutes 5–10% (w/w) of the total mixture to form the asphalt concrete.

How is asphalt mixture made?

Asphalt pavements are made by combining rocks and sand to a particular recipe and then adding asphalt cement as the black sticky glue that holds the pavement together. The combination of rocks and sand is very important to the structure and strength of the pavement.

What are 3 types of asphalt?

There are three main types of asphalt: Hot Asphalt, MC Cold Mix, and UPM. There are also different varieties of these asphalts for summer and winter use.

What are the different types of asphalt mixes?

HMA pavement mix types include Open-Graded Friction Courses (OGFC), Stone Matrix Asphalt (SMA), and fine- and coarse graded dense mixes.

What type of asphalt is best for driveway?

Hot mix asphalt is the most commonly used type of asphalt for residential driveways. It’s made up of aggregate and asphalt cement, heated and combined to form the final product. The asphalt is poured at the paving site, where a compactor presses it into shape.

What is the difference between Type 2 and Type 3 asphalt?

Type II, is considered flat and can be applied to surfaces up to 1/4 in 12 slopes. Type III, is considered to be “steep” asphalt but is limited to slopes up to 2 in 12, and Type IV is “special steep”.

What is the difference between Type A and Type B asphalt?

Some of the Differences between Types A & B are as follows: Type A hot mix requires that at least 90% of the coarse aggregate and 70% of Fine aggregate used contains crushed particles while Type B hot mix only requires 25% and 20% respectively.

What is the best grade of asphalt?

There are three different grades available in asphalt. The grades available are I-2, also known as base; I-5, known as top ;and the I-4 or commercial top grades.

What is 9.5 mm asphalt used for?

A single course of 9.5 mm mixture is recommended due to the confined areas generally involved where constructing Sidewalk, Golf Cart Paths or Bike Paths except where poor subgrade is encountered.

What is Type 3 binder asphalt?

NYSDOT Type 1 Base and Type 3 Binder Mixes



Base and Binder Mixes are a coarser grade of blacktop containing a higher percentage of larger stones. These larger stones increase in stability when added to the asphalt mix and also raises the load factor the surface can endure before breaking or cracking.

What is Type 7 blacktop?

Type 7 asphalt contains fine stone and dust which has a very smooth finish. Type 6 asphalt contains slightly larger stone, so it provides more strength but is not quite as smooth as Type 7. Once Sealcoated it is difficult to distinguish the difference in the textures.

What is Type L asphalt?

L: Light traffic mix designed with lower air voids for increased durability. Asphalt Base Course. Asphalt base course is that part of an asphalt pavement supporting the intermediate and wearing courses which rests directly on the subgrade or subbase pavement.