Table of Contents

Appendix F 4.3 Embedment Allowance (Ae)

Initial treatments

Typical embedment allowances (in L/m2) are shown in Figure F 7.

Figure F 7: Embedment allowance for initial treatments

Note: It is recommended that the following alternatives be considered where the ball embedment value exceeds 3 mm:

  • If due to moisture, defer sealing to allow the surface to harden as it dries back. The surface should be retested once it has dried sufficiently.
  • Apply a small aggregate seal as the first seal to act as an armour-coat and minimise the amount of embedment of the larger aggregate applied at a later date, say after about 12 months.


Embedment of aggregate may occur in reseals:

  • if there is free binder on the surface being resealed
  • when applying a reseal over fresh asphalt or microsurfacing
  • when applying a reseal over fresh maintenance patching.

Binder absorption by pavement

Initial treatments

Binder from a seal may drain into voids in the surface of the base course if these have not been adequately filled by a prime or initial seal. This is most likely to occur in sandy or silty rubble base materials (sandstone, limestone or silty gravels) in a hot dry climate.

It is strongly recommended that all new pavement surfaces should be primed or initial sealed. However, in some areas a seal is applied directly to the prepared granular pavement and the following binder absorption allowances provide a guide for use in these situations:

  • granular unbound pavements

allow +0.1 to +0.2 L/m2

  • pavements using cementitious binder

allow +0.0 to +0.1 L/m2

  • bitumen stabilised pavements

allow –0.1 to +0.1 L/m2

  • pavements using chemical binders

For the use of chemical binders, refer to Austroads Guide Part to Pavement Technology Part 4D (Austroads 2006)


Binder absorption into the existing surface will seldom be a problem unless the existing surface is visibly open and porous.

Binder absorption by aggregate

Absorptive aggregates may fall into two general categories:

  • Porous, e.g. sandstone, rhyolite etc.
  • Vesicular (full of cavities), e.g. scoria, slags etc.

In general, binder absorption into aggregate is not applicable, but if an allowance is required, it does not usually exceed 0.1 L/m2.