idot update
DESCRIPTION
IDOT Update. Eric E. Harm Assistant Chief Engineer IAAP - May 17, 2007. Materials Audit. Materials Audit. Office of Auditor General / KPMG Before 2004 (Laid-back) – MISTIC was good enough 2004-6 (Under a microscope) – source documents required. Needed Corrections. - PowerPoint PPT PresentationTRANSCRIPT
IDOT UpdateEric E. Harm
Assistant Chief EngineerIAAP - May 17, 2007
Materials Audit
Materials Audit Office of Auditor General / KPMG Before 2004 (Laid-back) – MISTIC was good
enough 2004-6 (Under a microscope) – source
documents required
Needed Corrections Accept and assign all materials using
proper Method of Acceptance Training Provide up-to-date information for
materials inspectors
Impacts to Industry Sampling/testing of materials that have
not been tested in some time will now be done. Rip Rap – Gradation/sizes need to be measured Plant site sampling and testing may result in
questions back to source Your cooperation and understanding is
greatly appreciated
WipFrag
WipFrag Working on getting approved for use Full Implementation - Jan. 2008 (?)
RAP
Recycled Asphalt Pavement
% Changes in HMAHMA MIXTURES 1/ MAXIMUM % RAP
Ndesign Binder/Leveling Binder
Surface Polymer Modified
30 30 30 10
50 25 15 10
70 15 / 25 2/ 10 / 15 2/ 10
90 10 10 10
105 10 10 10
1/ For HMA Shoulder and Stabilized Sub-Base (HMA) N-30, the amount of RAP shall not exceed 50% of. the mixture2/ Value of Max % RAP if 3/8 RAP is utilized.
SpG for Natural Aggregate RAP
Northern Districts (1 & 2) = 2.660 Southern Districts (3 – 9) = 2.630
Steel Slag RAP will still be tested before use
Talking about Fractionating for more consistency
Field VMA
Field VMA Currently - VMA is tested in the design
phase only Now – VMA will be tested in production
phase
Why do we need Field VMA?
Why do we need Field VMA? Maintain the correct amount of effective (not
absorbed) AC
Prevent over & under asphalting
Better tool for trouble shooting/controlling mixes
Purchase mix that better represents mix design
Improved resistance to stripping
Mix durability – uniformity should lead to longer
performance
How Aggregates Can Affect VMA Angularity Hardness Specific Gravity
Friction Trailer
Friction Trailer This week - being calibrated at NASA New aggregate types are tested with
trailer before given friction category for HMA use
7 years since the new friction policy went into affect
ASR
Alkali-Silica Reactivity
Spec. Overview Each Gravel and Natural Sand Source are:
Being tested using ASTM 1260 Given an ASR Expansion #
Based on ASR Expansion # Mitigation may be necessary when used Various Mitigation Options Available
Limestone and Dolomite Sources are given a predetermined ASR Expansion #
Implementation Currently, on a trial basis, used in Dist. 1
and 4 Bigger Concrete Jobs Future - Statewide Implementation
Not IDOT
IDOT
Thank You