Browsing by Author "Obianyo, Ifeyinwa I."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Influence of moisture and geofluids (GF) on the morphology of quarry fines treated lateritic soil
    (Cleaner Engineering and Technology, 2021) Onyelowe, Kennedy C.; Obianyo, Ifeyinwa I.
    The influence of moisture migration in the form of GF on the morphology of lateritic soil has been studied with laboratory experiments. This was important due to the effect of adsorbed moisture during molding moisture addition in a stabilization protocol that gives rise to hydration. In addition, moisture adsorption and absorption play a very vital engineering role during the seasonal changes of wet and dry seasons when the water table rises and drops. This occurrence brings about alternate effects of wetting and drying of hydraulically bound structures like in pavement foundations. Therefore, it was pertinent to study how these changes affect soil microstructure to enable good design decisions. The soil used in this exercise was classified as highly plastic, poorly graded A-7-6 soil group according to AASHTO classification method. The soil was mixed with various proportions of quarry fines under different molding moisture conditions and the specimens were prepared for scanning electron microscopy (SEM) exposure. The results of the SEM exposure showed that GF applied here as molding moisture improve the agglomeration of treated soil particles to form flocs in a stabilization process. However, the microspores and crack propagation were observed more in the structure with less amount of quarry fine, i. e., at 2% QF than that at 4% QF. This showed the pozzolanic effect of QF on soil under the influence of GF. GF in all its forms should be studied for sustainable earthwork design and construction.
  • Thumbnail Image
    Item
    Morphology and mineralogy of rice husk ash treated soil for green and sustainable landfill liner construction
    (Cleaner Materials, 2021) Onyelowe, Kennedy C.; Obianyo, Ifeyinwa I.; Onwualu, Azikiwe P.; Onyia, Michael E.; Moses, Chima
    The morphology and mineralogy of the soil treated with rice husk ash (RHA) under different molding moisture conditions. Leachate condition in landfills built with compacted clay soil is damaging the underground water flow with the hazards released from disposed and decomposing waste materials. This makes landfills dangerous infrastructure. The leakage can be dealt with through the deployment of green materials developed from agricultural waste. One of such wastes is rice husk combusted to derive ash. The test soil used in this exercise has been classified as highly plastic and poorly graded. The treated soil was examined by scanning electron microscopy and x‐ray diffractometer methods. From the test results, the presence of goethite alongside quartz and kaolinite were observed in the XRD (X‐ray Diffraction) spectra of 6% and 10 % RHA treated soil. The Goethite possessing an inner needle‐like structure with a closed packed striated structure makes the composite a promising material for constructing landfill liners. This is because the closed packed striated structure of the goethite present in the composite will slow down the vertical seepage of leachate to allow its collection and removal by the leachate collection system. The composite will form a barrier between groundwater, soil, and substrata, and waste. From the SEM (Scanning Electron Microscopy), the uniformly distributed grain boundaries and smaller grain size of the composite (lateritic soil and RHA) will serve as a barrier to the movement of contaminants and other leachates to the groundwater and thus, making the composite a viable material for landfill liner system.