After the wet utilities (and dry utility crossings) are in, the street improvements can then be installed. It is very important for builders to install their streets because they cannot start building homes without it! And if you don’t have your model homes built, then you can’t start selling homes!

In this post we will be discussing:

1. Curb & Gutter
2. Typical Paving Section:
   • Aggregate Base Course (“AB”)
   • Asphalt Concrete (“AC”)
   • Cap Pave

CURB & GUTTER

After the utilities are installed, the first part of the street improvements to go in is the curb and gutter. The curb & gutter will work as a boundary for the paving. (In addition to the curb & gutter, other concrete items may also consist of catch basins and cross-gutters).

The curb & gutter is made out of concrete and is poured using a “Curb & Gutter” machine (see photo below).

TYPICAL PAVING SECTION

After the curb & gutter, the paving then goes in (see below for a typical paving section detail). The paving section of the street improvements consists of two layers (possibly three, see “Cap” Pave section) as shown below:

1. Aggregate Base Course (“AB”)
2. Asphalt Concrete (“AC”)
3. “Cap” Pave

1. Aggregate Base Course

The first layer in the street is called the “BASE” (also known as “Aggregate Base” or “AB”), which sits underneath the asphalt section. It typically consists of larger crushed aggregate (3/4”), which the contractor spreads and compacts in order to provide a stable base for the asphalt pavement. There are different types (or “classes”) of base, but the most common type is “Class 2 Base”.

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2. Asphalt Concrete

The second layer is the asphalt section and is poured over the base. This is the “AC” (or “ASPHALT CONCRETE”) and is very sticky and dark, and it is typically made up of asphalt cement, sand, crushed rock, and bitumen. Due to its highly viscous nature the asphalt is poured at a very high temperature.

The notation for a street section that you’ll commonly see (and hear) in the construction world will look something like this: 4” AC / 6” AB (or 0.33’ AC / 0.50’ AB).

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3. Cap Pave

In some cases, many builders will install their entire street section EXCEPT for the top 1″ to 2” of AC. This remaining section is the “CAP PAVE”. Builders like to do this because any superficial damages done to the street during the building can usually be resolved and covered at the end by pouring a fresh new layer of AC. On the flip side, if you install streets without a cap pave (or at “full lift”), the repairs from damages could be a lot more extensive and cost a lot more money!

But be sure to do you research, because not all cities or jurisdictions will allow a cap pave!

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**Watch the video below to see what an actual Street Improvements plan set looks like!

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