Project Details
RESEARCHERS
Robin Kline, Xianming Shi
SPONSORS
Office of the Assistant Secretary for Research and Technology
KEYWORDS
Concrete pavements, Durability, Fly ash, Geopolymer concrete, Infiltration, Mix design, Nanostructured materials, Sealing compounds, Water quality management
Project description
The project will take the advantage of two WSU-patented technologies (US Patent 10647612 on geopolymer binder and a provisional patent on nano-engineered penetrating sealer) to develop a sustainable pervious concrete technology. Different from conventional pervious concrete, this technology will feature: (1) 100% replacement of cement by a cement-free and biochar-amended geopolymer binder with less than 0.05 wt.% graphene oxide (a novel nano-material); (2) greatly improved durability of the pervious concrete pavement by customized design of initial water infiltration rate and treatment of hardened concrete by a nano-engineered waterproofing sealer. It is expected that the use of fly ash and biochar in place of portland cement and the extended service life of pervious concrete will both contribute to great reduction in the life-cycle footprint of the pavement. This proposed work fits well under the ERTC3 thrust area of “Sustainable construction materials and practices”. This research consists of three main tasks. Task 1 will focus on optimizing the type and dosage of nanomaterials used for the siliconate-based penetrating sealer, the mix design of biochar/fly ash geopolymer pervious concrete customized to feature infiltration rates consistent with the local rainfall rates, and the timing and procedure to apply the sealer onto the pervious concrete pavement. The objective is to achieve a reasonable balance between mechanical properties, infiltration performance, and water absorptivity. Task 2 will focus on the evaluation and potential improvement of the performance of sealer-treated geopolymer pervious concrete, in terms of: freeze/thaw resistance, salt scaling resistance, abrasion resistance, and sulfate resistance. The objective is to achieve an acceptable level of durability in aggressive environments of concern. Advanced microscopic investigations will be conducted to shed light on the roles played by selected nanomaterials in both the sealer and the geopolymer pervious concrete. Task 3 will evaluate the environmental benefits of the sealer-treated geopolymer pervious concrete pavement, starting with its ability to treat typical pollutants-laden stormwater from roadways. Portland cement pervious concrete will be used as control to compare with this “greener” pervious concrete. The simulated stormwater will include pollutants such as copper, zinc, sulfate, ammonia, nitrate, total phosphate, petroleum hydrocarbons and sodium chloride.