Development of Environmentally-Friendly Stabilization Methods for Transportation Infrastructure Based on Geopolymers

University Transportation Centers Program2018PDFTech ReportRadovic, MiladinPuppala, Anand J.Samuel, RinuHuang, OscarBanerjee, AritraTransportation Consortium of South-Central States (Tran-SET) University Transportation Center for Region 6Louisiana State University (Baton Rouge, La.)United States. Department of Transportation. University Transportation Centers (UTC) ProgramUnited States. Department of Transportation. Office of the Assistant Secretary for Research and TechnologyTransportation Consortium of South-Central StatesTexasUnited StatesBase course (Pavements)ClayCompressive strengthDensityMoisture contentShrinkageSoil stabilizationSubgrade materialsSwellingGeopolymer concreteGround improvementStrength17GTTAM0269A3551747106Final report, May 2018 \u2013 May 2018Geopolymers (GPs) have received much attention as an eco-friendly and sustainable alternative to conventional chemical additives, since they can be processed at room temperatures from aqueous solutions by utilizing waste materials (e.g. fly ash) or abundant natural sources (e.g. clay). A collaborative research study is carried out by teams from Texas A&M University (TAMU) and University of Texas at Arlington (UTA) to investigate the effectiveness of GPs for stabilizing base and subgrade materials by considering the strength and shrink-swell characteristics. Two types of clay, obtained from the North Dallas area, were mixed with a potassium-based GP synthesized from metakaolin and silica fume, at a ratio of 8 wt% of dry geopolymer to dry soil, and cured for a period of 7 days. Moisture-density relationship tests conducted show that treated soils have a higher optimum moisture content and lower maximum dry density as compared to untreated soils. Treated soils exhibited significant reduction in shrinkage and swell properties as compared to untreated soils. Additionally, unconfined compression strength tests also show an increase in strength of treated soils.143