# Presentation: 451386

##  Specifications Current & Future Updates 

**Jack A. Scott, P.E.**
**Airports Division, Northwest Mountain Region**

## Asphalt Binders - Regional 

_**State**__**	**_**	**_**PG Binders  for Aircraft Gross Loading**__**	**__**	**_
**	****	****	****	**_**60K and Under**__**	**_**	**_**Over 60 K**__**	**_
**Colorado –Western****	****58-34****	****	****	****64-34**
**Colorado – Eastern****	****58-34****	****	****	****64-28**
**Idaho – Northern****	****	****58-34****	****	****	****64-34**
**Idaho – Southern****	****	****64-34****	****	****	****64-34**
**Montana – Western****	****58-34****	****	****	****64-34**
**Montana – Eastern****	****	****64-34****	****	****	****64-34**
**Oregon – Western****	****	****64-22****	****	****	****70-22**
**Oregon – Eastern****	****	****64-28****	****	****	****70-28**

## Asphalt Binders (cont.)

_**State**__**	**_**	**_**PG Binders  for Aircraft Gross Loading**__**	**_
**	****	****	****	**_**60K and Under **_**          **_**Over 60 K**_
**Utah****	****	****	****	****64-28****	****	****	****70-28**
**Washington – Western****	****64-22****	****	****	****64-22**
**Washington – S. Eastern****	****64-28****	****	****	****70-28**
**Washington – N. Eastern****	****58-34****	****	****	****64-34**
**Wyoming – Western****	****58-34****	****	****	****64-34**
**Wyoming – Eastern****	****64-34****	****	****	****64-34**

## PG + Specifications

**The binder (RTFO) aged residue shall be tested in accordance with AASHTO T 301 for Elastic Recovery.**
**Tested at 25 degrees C.  **
**The recovery shall be 50% minimum.**

## PG + Specifications

**Include following table for modified asphalt cements to be consistent with State DOT specifications for specified grade:**
_**Property **__**	**__**	**__**	**__**	**_**	**_**Min.**_
**Toughness, Inch-Pounds****	****75 **
**Tenacity, Inch-Pounds****	****	****50**
**(per ASTM D 5801)**

## Asphalt Specification Changes

- Cut Cold Joints Back 2 to 3 inches.
- Joint Density Directly on Joint.

## Vertical Cut Edge for Cold Joint

*Vertical Cut Edge for Cold Joint*

**Notes:**
To prepare the cold joint for the next mat, clean the joint area, and apply a tack coat if needed.
Some specs require the joint to be “cut back” 25 to 50 mm (1 to 2 in) before the next mat is placed.  This can be done with a saw, or a cutting wheel attached to a grader or loader.
The purpose of this is to remove the part of the mat that may have less density than the rest of the mat due to lack of confinement during compaction.
If traffic will not be passing over the mat, cutting back the joint while the mix is still warm requires less effort.
Cutting back definitely requires a tack coat.

## Wheel-Cutting

## Wheel-Cutting – With Shoe

## Luting – Do Not Broadcast

*Luting – Do Not Broadcast*

**Notes:**
If the transverse joint is constructed properly up to this point, there should be minimal luting necessary.
If the paver starts out on the blocks and the screed begins with a full head of material, the thickness of the downstream mat will be correct.
There is never a reason to lute a transverse joint excessively.
Remove and recycle any excess coarse aggregate left from luting the joint.  The appearance of the final mat is very important and should be as uniform as possible.
Do not Broadcast coarse material back onto mat.
Ask: What is the rake man going to do with material in front of the lute?

## Mix “Bumped Back” to Joint

**Compacted Mat**

**Uncompacted Mat**

*Mix “Bumped Back” to Joint*

**Notes:**
If the amount of material is properly placed, a simple “bump” of the mix with the lute will prepare the joint for compaction.
Do not “cast” mix across the mat.
Some contractors use a tow attachment to bump edge back.

## Transfer/ remix vehicle

**Transfer/ remix vehicle**

## Alkali - Silica Reactivity - ASR

***Alkali - Silica Reactivity - ASR***

***Pavement Deicers?***

## Alkali Silica Reactivity - ASR

**Fine and Coarse aggregates tested by the Contractor for alkali-aggregate reactivity - ASTM C 1260.  **
**Laboratory conducting the tests accredited for test method ASTM C 1260 under ASTM C 1077.  **
**Fine and coarse aggregates shall be evaluated separately in accordance to ASTM C 1260.  **

## Reactivity – ASR (Cont.)

**Each aggregate **_**source**_** shall be evaluated separately.  **
**Aggregates shall also be evaluated in combination - Modified ASTM C 1260.  **
**Results shall have a measured expansion of less than 0.08 percent at 28 days.  **

## ASR  Mitigation

**Utilize low alkali Portland cement and Min. 30% Class "F" fly ash. Expansion - less than 0.08 percent at **_**28**_** days. **
**Utilize low alkali Portland cement and ground granulated blast furnace (GGBF) slag.  Expansion to less than 0.08 percent at **_**28**_** days. **

## Reactivity – ASR (Cont.)

**If any ASTM 1260 expansions exceeding 0.08 percent during initial evaluation, conducted every 14 days of production.   **
**Aggregates from different sources shall be weighed and batched separately at the concrete batch plant.**