The National Academies

NCHRP 24-45 [Active]

Evaluating Mechanical Properties of Earth Material During Intelligent Compaction

  Project Data
Funds: $500,000
Staff Responsibility: Camille Crichton-Sumners
Research Agency: University of Texas at El Paso
Principal Investigator: Soheil Nazarian, Ph. D., P.E.
Effective Date: 7/27/2015
Completion Date: 12/31/2019
Comments: Research in progress

Compaction of earth materials for roadway construction is the primary activity to build embankment and to prepare subgrade, subbase, base, and stabilized layers of highways. Current standards of state highway agencies require contractors to build uniform material layers, without dependable means to continuously quantify and verify the degree of compaction. The implementation of intelligent compaction (IC) technology has the potential to provide continuous, real-time measurements for quality control/quality acceptance (QC/QA) of compaction. Specifically, Roller Integrated Compaction Monitoring (RICM) [i.e., IC or Continuous Compaction Control (CCC)] uses rollers equipped with sensors that record location and layer stiffness. Current IC technology depends solely on the roller measurement values (MVs), which represent a composite value of compacted layers within a zone of influence, approximately 1 m (3.3 ft) in depth. MVs are influenced by variation in layer thickness, moisture, layer stiffness, machine vibration, drum-soil interaction, etc. The inability to associate the contribution of these variables on MVs is an obstacle for implementing IC technology in construction acceptance. Overcoming this obstacle requires a better understanding of the mechanical properties of earth materials governing IC compaction.
The objective of this research is to develop procedure(s) that measure the mechanical properties of earth materials to facilitate the adoption of dynamic and static compaction using IC technologies for field acceptance. Earth materials include unbound aggregates, and both coarse and fine grained soils.
The work proposed must be divided into tasks and proposers must describe in detail the work proposed in each task. The tasks must be divided into two phases. Phase I will consist of information gathering and planning tasks, culminating in the task to submit the interim report (IR). The IR will describe in detail the work completed in the Phase I tasks. In addition, the IR will include an updated Phase II work plan, which will describe the manner in which the proposer intends to use the information obtained in Phase I to satisfy the project objective. Also, the IR will provide an annotated outline of the final report to be published. The IR will be presented and discussed at a face-to-face interim meeting with NCHRP. The project schedule should include 1 month for NCHRP review and approval of the IR. Work on the Phase II tasks shall not commence until the updated Phase II work plan is approved by NCHRP. A kick-off teleconference between the research team and NCHRP shall be scheduled within 1 month of the contract’s execution to discuss the research plan. A detailed description of any proposed survey or field investigation shall be submitted to NCHRP for prior review and approval.


Task 1. Information Search

Task 2. Identify limitations of IC technology

Task 3. Develop detailed work plan

Task 4. Submit an Interim Report

Task 5. Conduct Work Plan approved in Task 4

Task 6. Prepare Work Plan for Field Validation

Task 7. Implement Field Validation Work Plan

Task 8. Prepare Project Final Report

 STATUS:Research in Progress

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