BACKGROUND
State departments of transportation (DOTs) routinely receive requests from vendors to approve new products and materials. These products may involve in-the-field curing of materials such as sprays, foams, epoxies, or resins in constructing or maintaining culverts, pipes, or bridge supports. These products are in contact with surface water and may pose adverse impacts to water quality. Although manufacturers may provide evidence of meeting required laboratory testing standards indicating minimized or no impacts to water quality, several studies have nonetheless documented adverse effects during and after installation. Although some DOTs have developed specifications for certain repair methods, they do not have methods to screen products for environmental impacts. Finally, the fast-paced nature of product innovation presents DOTs with several challenges to ensuring products will not put surface waters at or near project sites at risk.
Products should be screened before use and properly field-cured to minimize adverse water-quality effects. Even with screening, risks may manifest from (1) the product not performing outside of laboratory conditions due to differing environmental conditions that are difficult to simulate, (2) installation not being performed to manufacturer specifications, (3) incomplete cure or extended cure times, and/or (4) long-term abrasion of the product from debris or sediment flows. Research is needed to provide DOTs with a standard framework to consider a range of products and installation procedures that require in-the-field curing and mechanisms to minimize risks to water quality.
OBJECTIVE
The objective of this research is to develop a three-part guide for evaluating products that cure in the field, such as sprays, foams, epoxies, or resins used in constructing or maintaining culverts, pipes, or bridge supports that may be in contact with surface water.
At a minimum, the guide will deliver (1) a testing protocol for manufacturers to follow so that DOTs can qualify in-the-field curing products prior to product approval, (2) an implementable and consistent protocol with methods for field testing to ensure minimum impact on water quality, and (3) procedures or processes for DOTs to address risk factors.
Accomplishment of the project objective will require at least the following tasks.
TASKS
The sequencing of tasks and deliverables (such as technical memorandums or summary reports) shall be structured for delivery in quarterly progress report submissions. There will be three project phases, with an interim report and updated research plan due after Phases I and II. An in-person interim meeting should follow the submission of the first interim report, with a virtual meeting following the second. The research agency shall not proceed to the next phase without NCHRP's approval of the interim reports and updated research plans.
PHASE I
The first project phase comprises developing or approving cornerstone elements of the research plan and is estimated to be accomplished in two project quarters. Phase I shall include the delivery of (1) the amplified research plan, (2) a kick-off meeting (with summary notes), (3) a scan of practice and literature review, and (4) potential sites for in-field and/or laboratory testing.
The scan of practice and literature review shall be multifaceted and support the research methodology. At a minimum, the following considerations must be included:
- Current state DOT practices on evaluating products that require in-the-field curing
- Variables that affect water quality
- Product or material characteristics that influence the potential to leach
- Climatic or environmental conditions (heat, humidity, freeze-and-thaw cycles, etc.)
- Site conditions (terrain, soils, frequency of water exposure, etc.)
- Chemical components of field-cured products and their impacts on aquatic habitats and relevant testing methods
- Water-quality indicator parameters
- In-field testing for quality control and the state of cure
- Relevant testing protocols and methods to evaluate product impacts on water quality
Note: There are two NCHRP synthesis projects on topics that may assist the research team in avoiding duplication of effort: NCHRP 20-05/53-19 “State DOT Product Evaluation Processes” (found here https://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=5253) and NCHRP 20-05/54-01 “Practices to Identify and Mitigate PFAS Impacts on Highway Construction Projects and Maintenance Operations” (found here https://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=5284).
To complete the second project quarter, the research team shall deliver the first interim report and updated Phase II research plan with an in-person interim meeting. A detailed outline for the guide shall be included in the interim report. One month shall be reserved for review and NCHRP approval.
PHASE II
The second project phase shall explore the critical elements required for developing a three-stage guide that accommodates emerging products. This phase is estimated to be accomplished in six project quarters. Each project quarter shall result in a summary report of preliminary research findings for panel review in each quarterly progress report.
To achieve the first and second parts of the research objective, the research team shall develop an initial screening protocol to evaluate in-the-field curing of products. The protocol could include novel or proxy methods, cost-effective benchtop methods, or modified or partial field tests. Environmental conditions or other risk factors should inform the methods to ensure the protocol is applicable to the range of climatic regions and site conditions. The protocol should be performable by commercial laboratories accessible to manufacturers and should help DOTs effectively determine when a product may not be suitable due to aquatic impacts.
To develop the testing and evaluation protocols, the research team may work closely with state DOTs to identify sites and/or develop a means to simulate installations of these technologies in a laboratory or controlled outdoor setting that matches the proposed uses of the products. These simulations should be used to evaluate the effectiveness of the testing and evaluation protocol(s) in assessing the risk to water quality from the installation under different field conditions.
To achieve the third research objective, when a product is approved for use, state DOTs should have processes to address known risk factors contributing to impacts on water quality, for example, model contract specifications, installation requirements, requiring certified installers, observation periods, or additional in-field testing.
In the last quarter of Phase II, the research team shall deliver the second interim report and updated Phase III research plan with a virtual interim meeting. The updated research plan, through a predraft guide, shall specify the content and format for the three-stage framework required in the final deliverables, including recommended test methods for laboratory and/or field use. The guide will deliver elements described in the research objective. One month shall be reserved for review and NCHRP approval.
PHASE III
The project's third phase shall be reserved for developing the final deliverables and not exceed two project quarters. The final deliverables shall include the following:
- A guide,
- A conduct of research report that documents the entire research effort,
- A PowerPoint presentation with speaker notes that summarizes the project and distinctly illustrates for the audience how the research can be applied in their organization,
- A draft article suitable for publication in TR News (no guarantee of publication is implied), and
- An Implementation Plan.
STATUS: A response has been received for this RFP. The project panel will meet to determine next steps.
