Quality Construction

1
Quality Construction Equipment Plants, Pavers,
and Compactors

• Plants, Pavers, and Compactors
• By Rich Wolters, and
• Dwight Beglau

2
MnDOT Specifications

• Prior to 1958 - no density control on HMA
• 1958 - 98 Hveem many problems
• 1959 - 97 Marshall for 2351
• 95 Marshall for 2341
• 90 Marshall for 2331

3
Mn/DOT Specs Continued

• 1964 1968 Spec Book
• 95 Marshall for 2331 2341
• 97 Marshall for 2351 (Divided Aggregate)
• Ordinary Compaction (judgment)
• July 1, 1969 Supplemental Spec
• Added 2361 (1/2 max. fine mix)
• by Ordinary Compaction

4
MnDOT Density Research

• 1969, 1970 1971 pilot density projects and
  analyzed historical for wearing courses
• Developed statistical concepts

5
Research and Supplementals

• Nondestructive (Backscatter)
• 1978 three methods ( Marshall/Core, Ordinary
  and Control Strip)
• 1978 Control Strip required unless otherwise
  noted
• 1978 Intro. Price Adjustment schedule

6
1986 QM Era Testing Standardization
A

• Saturated Surface Dry SG B-C
• Mechanical Marshall Compaction
• Rotational Base/Beveled Foot
• Bottom Line ?Increased Density
  Requirements

7
By 1991 - Specs

• Control Strip Pay Factors
• Specified Density now SSD
• Ordinary Nuclear/monitoring
• for Rolling Pattern
• Modified Specified (2340) to SSD
• Total Pay Factor (A) X (B)
• Rice (MTD)
• Modified Control Strip for Night Paving

8
Rolling Equipment

• Pre 1958
• 3-wheel steel small pneumatic
• 1958 to late 60s
• Tandem steel pneumatic
• Air on run (35) for breakdown

9
Rolling Equipment

• 1970s to present evolution of vibratory
• Pneumatic rollers almost disappeared except for
  late fall paving
• Pneumatic again for Superpave