Case Studies in Construction Materials (Jul 2023)
The effect of using nano agriculture wastes on microstructure and electrochemical performance of ultra-high-performance fiber reinforced self-compacting concrete under normal and acceleration conditions
Abstract
This research investigates the effect of using nano agriculture waste as a partial substitute to solve increased climatic concerns in addition to producing modern ultra-high-performance fiber reinforced self-compacting concrete (UHPFC-SCC). Three types of nano materials have been incorporated, namely nano sugar cane bagasse ash (NSCBA), nano cotton stalk ash (NCSA), and nano rice straw ash (NRSA) with dosages of 1%, 2%, and 3%, respectively. Fresh concrete properties have been investigated via flow and V-funnel tests while compressive strength was evaluated up to 90 days. X-ray diffraction (XRD) analysis, Raman spectroscopy analysis and scanning electron microscopy (SEM) alongside energy dispersive spectroscopy (EDS) was performed to compliment the strength data. Finally, electrochemical measurements including linear polarization (LPR), open circuit potential (OCP) and impedance spectroscopy were investigated at normal and accelerated corrosion conditions on HSS (high strength steel Gr 60). Results demonstrate that compressive strength improved in the range of 18%− 21% between 28 and 90 days using 3% NSCBA, 3% NRSA or 1% NCSA. This is attributed to the facts that optimum dosage of nano wastes results in densification of the UHPFC-SCC matrix and strength magnitude depended on intertwining of high Ca/Si molar content in the range of 3.14–7.1 compared to 0.52 observed in the control mix (EDS analysis). Further, electrochemical measurements revealed that nano materials improved the charge transfer resistance and bulk resistance of HSS interface as well as retarded the flow of electrons between anode and cathode sites consequently limited the propagation of corrosion.
