Research in Progress (RIP) https://rip.trb.org/ en-us Copyright © 2026. National Academy of Sciences. All rights reserved. http://blogs.law.harvard.edu/tech/rss tris-trb@nas.edu (Bill McLeod) tris-trb@nas.edu (Bill McLeod) Research in Progress (RIP) https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg https://rip.trb.org/ Effect of Using RAP on Gravel Roads https://rip.trb.org/View/2720399 Tue, 30 Jun 2026 15:25:11 GMT https://rip.trb.org/View/2720399 Development of Crushed Quarry Aggregate Surfacing Specifications https://rip.trb.org/View/2533742 Tue, 01 Apr 2025 08:39:01 GMT https://rip.trb.org/View/2533742 Iowa Granular Road Structural Design Tool https://rip.trb.org/View/2509060 Wed, 12 Feb 2025 18:54:45 GMT https://rip.trb.org/View/2509060 Feasibility of Granular Road and Shoulder Recycling Phase II: Gradation Optimization for Improved Performance https://rip.trb.org/View/2509059 Wed, 12 Feb 2025 18:47:28 GMT https://rip.trb.org/View/2509059 Base Stabilization of Iowa Granular Roads Using Recycled Plastics https://rip.trb.org/View/2509058 Wed, 12 Feb 2025 18:41:04 GMT https://rip.trb.org/View/2509058 Introducing Smart Materials in Granular Roadway and Pavement Foundation Systems for Mitigating Freeze-Thaw Damage https://rip.trb.org/View/2509048 0 °C) for longer which will minimize the existing and capillary water in soils to freeze and form ice lenses thereby preventing frost heave and strength loss in subgrade soils. This hypothesis will be tested via a series of state-of-the-art laboratory-scale tests under various settings, and numerical modelling. The proposed research contains three phases: (1) characterization; (2) optimization; and (3) performance. The characterization phase will determine the index and physicochemical properties of soils, PCMs, and soil-PCM mixtures while the optimization phase will determine the best inclusion method for PCMs in soils. Experiments in the performance phase will evaluate how PCM inclusion impacts the frost heave and the strength loss after freezing and thawing.]]> Wed, 12 Feb 2025 17:04:42 GMT https://rip.trb.org/View/2509048 An Economical and Sustainable Dust Suppressant for Gravel Roads https://rip.trb.org/View/2508967 Wed, 12 Feb 2025 12:37:54 GMT https://rip.trb.org/View/2508967 Effectiveness and Guidance of Aggressive Rehabilitation of Gravel Roads https://rip.trb.org/View/2508946 Tue, 11 Feb 2025 18:50:09 GMT https://rip.trb.org/View/2508946 Gravel Road Performance Enhancements – Phase II https://rip.trb.org/View/2507250 Mon, 10 Feb 2025 14:11:01 GMT https://rip.trb.org/View/2507250 Aggregate Specification to Reduce Dust and Improve Sustainability of Local Rock-Surfaced Roads https://rip.trb.org/View/2255777 Tue, 26 Sep 2023 16:04:24 GMT https://rip.trb.org/View/2255777 Evaluation of Gravel Stabilizer Used on Gravel Roads and Gravel Shoulders https://rip.trb.org/View/1913339 Fri, 11 Feb 2022 11:22:47 GMT https://rip.trb.org/View/1913339 Analysis of Benefits and Costs for Gravel and Unpaved Roads https://rip.trb.org/View/1875087 Fri, 27 Aug 2021 13:44:05 GMT https://rip.trb.org/View/1875087