01336758

Component

Three test sections were established in 2005 along a section of the Kancamagus Highway in New Hampshire, where different reconstruction techniques were used: conventional reconstruction, full depth reclamation (FDR), and FDR with cement-stabilized base (CTB). In 2008, extensive falling-weight deflectometer testing was conducted during the winter and spring thaw periods to investigate variations in pavement stiffness that result from seasonal changes in temperature and moisture. Modulus values of the various pavement layers were backcalculated and used with other pavement cross-section information to evaluate pavement service life and to predict the eventual failure mode of the three experimental sections. Despite the higher fines content in the subgrade beneath the FDR sections, the cement-treated FDR base was substantially stiffer than the crushed gravel base in the conventional reconstruction section during spring thaw, and, after mid-April, the untreated FDR base modulus values were also slightly higher than the base modulus values in the conventional reconstruction section. During normal operating conditions, the number of allowable repetitions for failure of the three different test sections is comparable. During the spring thaw-weakened period, all three test sections became more vulnerable to damage, with the cement-treated FDR base layer showing the greatest reduction in allowable repetitions for fatigue failure, attributable to its relatively low thickness and the poor quality of subgrade support at that location. Asphalt fatigue cracking was the predicted failure mode for the conventional reconstruction and untreated FDR sections, while CTB fatigue cracking was the predicted failure mode for the cement-treated FDR section.

01329018

11-2612

English

16p

2011

Transportation Research Board 90th Annual Meeting

DVD

Figures (9) ; References (15) ; Tables (2)

Crushed rock; Failure; Falling weight deflectometers; Freeze thaw durability; Full-depth reclamation; Pavement layers; Reconstruction; Recycled materials; Stiffness; Subgrade (Pavements); Test sections

Cement stabilized base

New Hampshire

Highways; Materials; Pavements; I33: Other Materials used in Pavement Layers

Transportation Research Board Annual Meeting 2011 Paper #11-2612

TRIS, TRB

Feb 17 2011 6:13PM