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High Performance Concrete Pavements
Project Summary

CHAPTER 24. MISSISSIPPI 1 (US 72, Corinth)

Introduction

The Mississippi Department of Transportation (MDOT) constructed an experimental project in 2001 under the TE-30 program to investigate the performance of a resin-modified pavement (RMP). RMPs are a new composite paving material consisting of a thin layer (50 mm [2 in.]) of open-graded hot mix asphalt (HMA) whose internal voids (approximately 30 percent) are filled with a latex rubber-modified portland cement grout (MDOT 1999). RMPs provide a tough and durable pavement surface that resists rutting, surface abrasion, and deterioration due to fuel spillage (Anderton 1996). To date, they have been used almost exclusively on military bases, but current research suggests they are suitable for any low-speed traffic application where resistance to heavy loads, tracked vehicle traffic, or fuel spillage is required (Anderton 1996). The cost of an RMP is typically about 50 to 80 percent higher than a comparable HMA pavement, but about 30 to 60 percent less than a comparable PCC pavement design (Anderton 1996).

To evaluate the performance of RMP, the MDOT constructed a series of test sections under the TE-30 program on US 72 in Corinth (see Figure 68) in 2001. These test sections were constructed at two HMA pavement intersections on US 72 that have a history of rutting and high traffic loading. For comparison purposes, an alternative pavement was constructed at each intersection adjacent to the RMP but in the opposite traffic direction. One of the alternative pavements was an ultrathin whitetopping (UTW) design, the other was a polymer-modified HMA pavement.

Figure 68. Location of MS 1 project.

Location of MS 1 project. An outline map of Mississippi shows the Mississippi 1 project on US Route 72 in Corinth, near the northeastern border of the State. The major Interstates, I-55 and I-20, are shown intersecting in Jackson near the center of the State.

Study Objectives

The objective of this project is to construct a demonstration RMP highway project and compare its performance to that of a UTW overlay and a polymer-modified HMA overlay.

Project Design and Layout

The construction of this experimental project took place from April to June of 2001. A total of four test sections were constructed at two different intersections on US 72 in Corinth:

  • Intersection of US 72 and Hinton Street, South Parkway, and Liddon Lake Road.
    • RMP in eastbound lanes.
    • UTW overlay in westbound lanes.
  • Intersection of US 72 and Cass Street.
    • RMP in eastbound lanes.
    • Polymer-modified HMA overlay in westbound lanes.

Figure 69 shows the layout of the test sections at the intersection of US 72 and Hinton Street, South Parkway, and Liddon Lake Road, while Figure 70 shows the layout of the test sections at the intersection of US 72 and Cass Street.

Figure 69. Layout of test sections at the intersection of US 72 and Hinton Street, South Parkway, and Liddon Lake Road.

Layout of test sections at the intersection of US 72 and Hinton Street, South Parkway, and Liddon Lake Road. The eastbound and westbound lanes of US 72 are shown. A section of 2-in. resin-modified pavement 310 ft long is in the eastbound lanes of US 72 near Hinton Street, and a 474-ft section of 3-in. ultrathin whitetopping in 3 ft by 3 ft panels is in the westbound lanes at the approach of South Parkway and Lidden Lake Road.

Figure 70. Layout of test sections at the intersection of US 72 and Cass Street.

Layout of test sections at the intersection of US 72 and Cass Street. The eastbound and westbound lanes of US 72 and the ramps for Cass Street and Hinton Street are featured. The 290-ft section of 2-in. resin-modified pavement is in the eastbound lanes of US 72 and ends at Hinton Street, and a 450-ft section of 4-in. hot-mix asphalt PG 82-22 in the westbound lanes ends at Cass Street.

The existing HMA pavement varied in thickness from 250 to 350 mm (10 to 14 in.), and was exhibiting rutting typically between 25 and 38 mm (1 and 1.5 in.). This portion of US 72 carried approximately 22,600 vehicles per day in 2000 (including about 10 percent heavy trucks). The projected cumulative KESALs in one direction for 20-year design life are 11,257 and 7,257 for rigid and flexible pavements, respectively.

At both intersection locations, the RMP was constructed 50 mm (2 in.) thick. The existing HMA pavement was first milled to a depth of 50 mm (2 in.), after which a 50-mm (2-in.) lift of open-graded HMA (PG 67-22) was placed. The cement grout containing a resin additive PL-7 was applied to the open-graded HMA the following day.

A 5000 lbf/in2 air-entrained concrete mix containing fibrillated polypropylene fibers was utilized for the UTW that was placed at the intersection of US 72 and Hinton Street. The existing HMA pavement was first milled to a depth of 75 mm (3 in.). The 75-mm (3-in.) UTW was then placed, with green sawing of the slabs conducted using Soff-Cut saws. The UTW was sawed into 0.9-m (3-ft) square slabs.

The polymer-modified HMA overlay was placed at the US 72 and Cass Street intersection. The existing HMA pavement was first milled to a depth of 100 mm (4 in.). The polymer-modified HMA with a 12.5 mm (0.5 in.) nominal maximum aggregate size (NMAS) and a PG 82-22 asphalt binder was then placed in two 50-mm (2-in.) lifts.

The excess milling of the existing pavement during the construction increased the unit costs of UTM and RMP sections. The unit cost of RMP sections was further increased by the removal of a portion of the sections due to the lack of full-depth grout penetration. The estimated and actual unit costs for these overlay treatments are shown in Figure 71.

Figure 71. Relative unit costs of the test sections.

Relative unit costs of the test sections. A chart compares the estimated and actual costs (in dollars per square yd) of constructing test sections of ultrathin whitetopping (UTW), resin-modified pavement (RMP), and hot mix asphalt (HMA). While for the 3-in. UTW (less than $30) and the 4-in. HMA (less than $10) the actual and estimated costs were close or the same, respectively, the actual costs for the 2-in. RMP test section were about $10 more per square yd (estimated at about $25 and actual about $36).

State Monitoring Activities

Construction Monitoring

During the construction of test sections, several incidents were observed by the researchers that might affect long-term pavement performance. These are summarized below (Battey 2002):

  • After the inside lanes of both RMP sections were constructed, the temperature in Corinth dropped to 32°F during the night. The severe cold slowed down the curing of the grout to such an extent that it appeared to be "powdering up" on the surface. However, the next day as the temperature warmed up, the powdering condition was not evident and the grout appeared to be gaining strength.
  • During the construction of the right lane of the HMA section, 10 vehicles drove on the fresh asphalt mat before the breakdown roller could begin compacting the section. The rutting due to the early traffic averaged 2.2 mm (0.09 in.) in the left wheelpath and 1 mm (0.04 in.) in the right wheelpath.
Performance Monitoring

MDOT will monitor the performance of these test sections for a period of 5 years. Performance data collected include Profile Index (PI), International Roughness Index (IRI), and skid number. Rutting data are also being collected for the HMA section.

Preliminary Results/Findings

Some preliminary performance data collected under the monitoring program are summarized in Table 37 (a-d). The monitoring of the construction and performance of these test sections has led to the following conclusions and recommendations (Battey 2002):

  • Table 37 indicates that the smoothness of the UTW test section is less than satisfactory, suggesting the need for smoothness incentive provisions.
  • In the construction of RMP, the gradation of the open-graded asphalt mix must be carefully controlled to ensure the target 30 percent air void level is obtained. Sufficient curing time (no less than 72 hours of above 50°F temperature) should be provided for the grout to obtain its design compressive strength.
  • The initial skid resistance of the RMP sections is less than satisfactory. However, as traffic begins to wear the top film of grout off the sections, the skid numbers begin to improve to more acceptable levels.
Table 37(a). International Roughness Index (IRI) Measured on the MS 1 Test Sections (mm/km)
DATEULTRATHIN WHITETOPPINGRESIN-MODIFIED PAVEMENTHOT MIX ASPHALT
AT CASS AT HINTON
Apr-01
5.42*
2.04*
2.36*
 
Jul-01
4.75**
1.78**
2.12**
1.41**
Aug-01
4.54**
1.76**
2.01**
1.32**
* IRI was collected in the right wheelpath using MDOT's ARRB Transport Research Walking Profiler.
** IRI is the average IRI of both wheelpaths collected using MDOT's High Speed "South Dakota Type" Profiler.
Table 37(b). Profile Index Measured on the MS 1 Test Sections (in./mi)
DATEULTRATHIN WHITETOPPINGRESIN-MODIFIED PAVEMENTHOT MIX ASPHALT
AT CASS AT HINTON
PI0.2"PI0.0PI0.2"PI0.0PI0.2"PI0.0PI0.2"PI0.0
Apr-01
100.03
148.28
11.42
27.8
23.53
59.21
 
 
Jun-01
 
 
 
 
 
 
16.03
35.24
Profile index was collected in the right wheelpath using a "California Type" Profilograph, and analyzed with both 0 and 0.2 in. blanking bands.
Table 37(c). Friction Numbers Measured on the MS 1 Test Sections
DATEULTRATHIN WHITETOPPINGRESIN-MODIFIED PAVEMENTHOT MIX ASPHALT
AT CASS AT HINTON
Apr-0136.8   
May-0133.224.423.4 
Jul-0133.329.831.835.8
Aug-0137.837.13836.9
Dec-0144.238.739.434.9
Skid resistance tests were conducted in the outside lane of each section with a test speed of 40 mi/hr.
Table 37(d). Rutting Measured in the MS 1 HMA Test Section (in.)
DATERUTTING (IN.)
LEFT WHEELPATHRIGHT WHEELPATH
Jul-010.090.04
Dec-010.130.08

Point of Contact

Randy Battey
Mississippi Department of Transportation
P. O. Box 1850
Jackson, MS 39215-1850
(601) 359-7648

References

Anderton, G. L. 1996. User's Guide: Resin Modified Pavement. Miscellaneous Paper GL-96-7. U.S. Army Center for Public Works, Alexandria, VA.

Battey, R. L. 2002. Construction, Testing and Preliminary Performance Report on the Resin Modified Pavement Demonstration Project. Work Order Document, Work Order DTFH71-99-TE030-MS-12 (State Study No. 137). Mississippi Department of Transportation, Jackson.

Mississippi Department of Transportation (MDOT). 1999. High Performance Concrete Pavement. Work Order Document, Work Order DTFH71-99-TE30-MS-12 (State Study No. 137). Mississippi Department of Transportation, Jackson.

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Updated: 04/07/2011
 

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