Establishing Best Practices for Construction and Design of Cement Treated Materials

Establishing Best Practices for Construction and Design of Cement Treated Materials

Form ProjStat (Rev. 5/2013)

(RTI)

Research Project Statement 18-25
FY 2018 Annual Program
Title: / Establishing Best Practices for Construction and Design of Cement Treated Materials
The Problem: / The demand for soil and base treatment and full-depth reclamation of existing pavement structures using cement continually increases with the scarcity of quality materials throughout Texas for the construction and rehabilitation of roadways. The use of recycled materials, such as reclaimed asphalt pavement (RAP) in base material has environmental and economic benefit because this reduces the demand for virgin aggregates and harvests the flexibility from asphalt binder. However, there are concerns with pavement performance of potentially using higher amounts of recycled materials.
These issues are compounded by the rapidly increasing traffic loading, such as unexpected overloading in energy sectors. Calcium based additives are frequently used to improve substandard materials and extensive knowledge and construction practices exist, but these practices vary among districts due to different traffic and weather conditions. TxDOT specifications, test methods, and practices need to be evaluated and revised where necessary to incorporate any new information, guidelines, and techniques, such as an inverted pavement structure, and products, such as super slurry. It is necessary to evaluate our current laboratory mixture design procedure and construction guidelines for TxDOT personnel and industry.
TxDOT has been constructing pavement structures with cement treated materials for many years. Specifications and test methods have been published; however, premature failures, such as rutting and cracking occasionally occur during or shortly after construction. It is critical to ensure long-term durability of treated materials is adequate to provide the structural support and quality required over the pavement design life. In general, premature failures of treated materials are partially due to the lack of understanding and knowledge of the significance of material mixture designs; and construction, inspection techniques, and best practices.
The following items may be considered:
  1. Identification of concerns and issues with concrete traffic barrier (CTB) throughout TxDOT districts.
  2. Soil and base material characteristics suitable for cement treatment.
  3. Cement content to provide adequate strength.
  4. Evaluation of slurry material versus powder applications and recommendations for slurry water-cement ratios.
  5. Benefits and challenges of usingTxDOT specifications Item 275, Cement Treatment (Road-Mixed), and Item 276,Cement Treatment (Plant-Mixed), which is more suitable for different situations.
  6. Quantification of benefits regarding thickness control, moisture control, and uniformity of compaction using a HMA paver for placing cement treated base.
  7. Adequate strength requirements for treated materials for pavement design of flexible and rigid pavements.
  8. Quantification of the value of micro-cracking.
  9. Material durability sufficient to withstand prevailing weather and environmental conditions.
  10. Construction and best practices, such as pulverization prior to mixing, uniformity of mixing, compaction, and optimum length of the construction section.
  11. Effectiveness of sealing for curing with either asphalt emulsion, sprinkling with water, curing compound, or any other material after compaction.
  12. The critical time when density has to be measured.
  13. Rapid test method to evaluate the durability and strength of the in-place material.
  14. The critical time at which the CTB can be open to traffic directly, and the maximum time period that the CTB can be open to the traffic prior to a subsequent layer is placed;
  15. Best practices and inspection guidelines.

Technical
Objectives: /
  1. Review soil and base cement treatment specifications, guidelines, best practices, and laboratory mixture design procedures from other state DOT's and private industry.
  2. Evaluate various roadway projects for field test sections requiring cement treatment.
  3. Evaluate the existing pavements for cement treatment prior to the treatment process.
  4. Perform laboratory mixture designs using innovated techniques and equipment.
  5. Perform non-destructive testing of field test sections.
  6. Develop guidelines for construction, inspection, laboratory mixture design, specification requirements, and for any other pertinent area of study.
  7. District or regional workshops and seminars for TxDOT district personnel.

Desired
Deliverables: /
  1. Technical memorandum for each task completed.
  2. Monthly progress reports.
  3. Value of Research (VoR) that includes both qualitative and economic benefits.
  4. Research report documenting work performed, methods used, and test results. Also includes guidelines for construction, inspection, best practices, laboratory mixture design, and recommendations for revision of current specifications and test procedures.
  5. Project Summary Report.
  6. Training material on material mix design, construction specifications, and inspections.

Proposal
Requirements: /
  1. Utilize the deliverable based templates (see the appendices provided or in the University Handbook)
  2. Proposals will be considered non-responsive and will not be accepted for technical evaluation if they are not received by the deadline or do not meet the requirements stated in RTI’s University Handbook.
  3. Proposals should be submitted in PDF format, 1 PDF file per proposal. File name should include project name and university abbreviation.

Pre-Proposal Meeting Information: / Monday, March 27, 2017 10:00AM – 12:00PM
Austin Riverside Campus
118 E. Riverside Dr.
RTI Conference Room, 1st Floor
Webex Information:
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Teleconference information:
Provide your phone number when you join the meeting to receive a call back. Alternatively, you can call:
Call-in toll-free number: 1-855-437-3563(US)
Conference Code: 734 178 806
Notifying RTI of Intent to Propose: / In order to be notified if additional project information is distributed by TxDOT, you must contact RTI, at (512) 416-4730 or by April 3, 2017, if you plan to propose.
Proposal
Deadline: / Proposals are due to RTI by 4:00 p.m. Central Time, May 11, 2017. Email submissions should be sent to .

Project Statement 18-25

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