Water Retention

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Ming Hung Wong - One of the best experts on this subject based on the ideXlab platform.

  • soil Water Retention behavior of compacted biochar amended clay a novel landfill final cover material
    Journal of Soils and Sediments, 2017
    Co-Authors: James Tsz Fung Wong, Zhongkui Chen, Xunwen Chen, Ming Hung Wong
    Abstract:

    Biochar has long been proposed for amending agricultural soils to increase soil-Water Retention capacity and therefore promotes crop growth. Recent studies revealed the potential use of biochar-amended soil in landfill final covers to promote methane oxidation and odor reduction. However, the effects of biochar application ratio, compaction Water content (CWC), and degree of compaction (DOC) on soil-Water Retention characteristics of biochar-amended clay (BAC) at high soil suction (dry condition) are not well understood. The present study aims to overcome this knowledge gap. Soil suction was induced using vapor equilibrium technique by a temperature- and humidity-controlled chamber, and the Water desorption (drying) and adsorption (wetting) Water Retention curves (WRCs) of compacted pure kaolin clay and peanut shell BAC with different biochar application ratios (0, 5, and 20 %, w/w), DOCs (80, 90, and 100 %), and CWCs (30 and 35 %) were measured. The correlations between these factors and the gravimetric Water content were analyzed by three-way ANOVA followed by the Tukey HSD test. The soil micro-structure was studied by scanning electronic microscope with energy-dispersive X-ray spectroscopy. Measured WRCs of BAC suggest that the soil-Water Retention capacity at high suction range (48.49–124.56 MPa) was in general increased, upon biochar application. The BAC compacted with CWC of 35 % at low (80 %) and high (100 %) DOCs for the 5 % BAC were increased by 7.30 and 9.77 %, when compared with clay, while the increases of 20 % BAC were 39.89 and 59.20 %, respectively. This is attributed to the embedded effects of clay particles in biochar pores, which reduce the total pore space of BAC. The soil-Water Retention capacity of BAC was also increased with CWC and decreased with DOC. The results of three-way ANOVA analysis show that the effects of DOC and biochar ratio on soil gravimetric Water content was significant (p < 0.05) only at 48.49 MPa on drying path. For other induced suctions, only effects of CWC were significant (p < 0.05). Biochar application increases soil-Water Retention capacity of the BAC at high soil suction (48.49–124.56 MPa) (dry condition) at both low (80 %) and high DOC (100 %). The soil-Water Retention capacity of 20 % BAC was much higher than that of 5 % BAC. BAC is a potential alternative landfill final cover soil with a higher soil-Water Retention capacity to be used in dry areas or regions with a long period of evaporation event.

  • soil Water Retention behavior of compacted biochar amended clay a novel landfill final cover material
    Journal of Soils and Sediments, 2017
    Co-Authors: James Tsz Fung Wong, Zhongkui Chen, Xunwen Chen, Ming Hung Wong
    Abstract:

    Purpose Biochar has long been proposed for amending agricultural soils to increase soil-Water Retention capacity and therefore promotes crop growth. Recent studies revealed the potential use of biochar-amended soil in landfill final covers to promote methane oxidation and odor reduction. However, the effects of biochar application ratio, compaction Water content (CWC), and degree of compaction (DOC) on soil-Water Retention characteristics of biochar-amended clay (BAC) at high soil suction (dry condition) are not well understood. The present study aims to overcome this knowledge gap.

James P Mcnamara - One of the best experts on this subject based on the ideXlab platform.

  • aspect influences on soil Water Retention and storage
    Hydrological Processes, 2011
    Co-Authors: I J Geroy, Molly M Gribb, Hanspeter Marshall, David G Chandler, Shawn G Benner, James P Mcnamara
    Abstract:

    Abstract : Many catchment hydrologic and ecologic processes are impacted by the storage capacity of soil Water, which is dictated by the profile thickness and Water Retention properties of soil. Soil Water Retention properties are primarily controlled by soil texture, which in turn varies spatially in response to microclimate-induced differences in insolation, wetness, and temperature. All of these variables can be strongly differentiated by slope aspect. In this study, we compare quantitative measures of soil Water Retention capacity for two opposing slopes in a semi-arid catchment in southwest Idaho, USA. Undisturbed soil cores from north and south aspects were subjected to a progressive drainage experiment to estimate the soil Water Retention curve for each sample location. The relatively large sample size (35) supported statistical analysis of slope scale differences in soil Water Retention between opposing aspects. Soils on the north aspect retain as much as 25% more Water at any given soil Water pressure than samples from the south aspect slope. Soil porosity, soil organic matter, and silt content were all greater on the north aspect, and each contributed to greater soil Water Retention. These results, along with the observation that soils on north aspect slopes tend to be deeper indicate that north aspect slopes can store more Water from the wet winter months into the dry summer in this region, an observation with potential implications for ecological function and landscape evolution.

Amr S Eldieb - One of the best experts on this subject based on the ideXlab platform.

  • self curing concrete Water Retention hydration and moisture transport
    Construction and Building Materials, 2007
    Co-Authors: Amr S Eldieb
    Abstract:

    Abstract Water Retention of concrete containing self-curing agents is investigated. Concrete weight loss, and internal relative humidity measurements with time were carried out, in order to evaluate the Water Retention of self-curing concrete. Non-evaporable Water at different ages was measured to evaluate the hydration. Water transport through concrete is evaluated by measuring absorption%, permeable voids%, Water sorptivity, and Water permeability. The Water transport through self-curing concrete is evaluated with age. The effect of the concrete mix proportions on the performance of self-curing concrete were investigated, such as, cement content and w/c ratio.

Cristina Jommi - One of the best experts on this subject based on the ideXlab platform.

  • fabric and clay activity in soil Water Retention behaviour
    Third European Conference on Unsaturated Soils E-UNSAT 2016, 2016
    Co-Authors: Cristina Jommi, Gabriele Della Vecchia
    Abstract:

    Modelling the Water Retention behaviour requires proper understanding of all the processes which affect the amount of Water stored in the pore network, depending on the soil state and the soil history. Traditionally, in many applications a single Water content – suction curve is used. This approach limits the applicability of the Retention data to practical cases, especially when fine grain soils are dealt with, when the deformability and activity of the clay fraction significantly affect the interaction with Water. On the other side, Water Retention is being recognised more and more as a fundamental information in the description of the mechanical response of the soil, as it provides the key connection to the partial volumetric strains in a deformation process. With reference to the work performed at the Politecnico di Milano in the last years, a contribution on the understanding and modelling the coupled Water Retention- mechanical response in deformable soils is presented. The contribution aims to: (i) summarise the mechanisms which contribute to Water Retention; (ii) point out the role played by an evolving fabric and the fluid properties on Water Retention; and (iii) provide an overview on some of the consequences of evolving Water Retention properties on the mechanical behaviour.

  • accounting for evolving pore size distribution in Water Retention models for compacted clays
    International Journal for Numerical and Analytical Methods in Geomechanics, 2015
    Co-Authors: Gabriele Della Vecchia, Annecatherine Dieudonne, Cristina Jommi, Robert Charlier
    Abstract:

    Water Retention in compacted clays is dominated by multi-modal pore size distribution which evolves during hydro-mechanical paths depending on Water content and stress history. A description of the evolutionary fabric has been recently introduced in models for Water Retention, but mostly on a heuristic base. Here, a possible systematic approach to account for evolving pore size distribution is presented, and its implications in models for Water Retention are discussed. The approach relies on quantitative information derived from mercury intrusion porosimetry data. The information is exploited to introduce physically based evolution laws for the parameters of Water Retention models. These laws allow tracking simultaneously the evolution of the aggregated fabric and the consequent hydraulic state of compacted clays. The influence of clay micro- structure, mechanical constraints and Water content changes on the Water Retention properties is highlighted and quantified from experimental data on different compacted soils with different activity of the clayey fraction. The framework is discussed with reference to a widespread Water Retention model and validated against experimental data on a Sicilian scaly clay compacted to different dry densities and subjected to a number of hydro-mechanical paths.

  • a Water Retention model for compacted clayey soils
    2013
    Co-Authors: Annecatherine Dieudonne, Gabriele Della Vecchia, Robert Charlier, Severine Levasseur, Cristina Jommi
    Abstract:

    The paper presents a Water Retention model accounting for the evolution of the aggregated structure of compacted clays along generalized hydromechanical stress paths. In this model, the Retention mechanisms of both microstructural and macrostructural levels are described separately using an expression of the type proposed by van Genuchten (1980). From the Water Retention model, a theoretical pore-size distribution (PSD) can be derived. Experimental PSD data on two compacted clays subjected to various wetting, drying and loading paths are exploited to provide a physical based calibration of the parameters of the Water Retention model. Not only they emphasize the evolution of some parameters, such as the air-entry pressure, along generalized stress paths but they also provide a quantification of these processes. On this basis, simple evolution laws are proposed. Finally, the Water Retention model is validated against other experimental data on the same materials compacted at different dry densities. The proposed formulation succeeds in tracking simultaneously the evolution of the fabric pattern and the hydraulic state of compacted clays along generalized stress paths.

  • an insight into the Water Retention properties of compacted clayey soils
    Geotechnique, 2011
    Co-Authors: Enrique Romero, Gabriele Della Vecchia, Cristina Jommi
    Abstract:

    Experimental data from different testing methodologies on different compacted clayey soils, with dominant bimodal pore size distribution, are presented and analysed, to provide a comprehensive picture of the evolution of the aggregated fabric along hydraulic and mechanical paths. Fabric changes are analysed both from the porous network viewpoint, by means of careful mercury intrusion porosimetry investigation, and from the soil skeleton viewpoint, by quantifying swelling and shrinkage of the aggregates in an environmental scanning electron microscopy study. The consequences of the aggregated fabric evolution on the Water Retention properties of compacted soils are analysed and discussed. A new model for Water Retention domain is proposed, which introduces a dependence of the intra-aggregate pore volume on Water content. The model succeeds in tracking correctly the evolution of the hydraulic state of the different soils investigated along generalised hydromechanical paths. The proposed approach brings to l...

James Tsz Fung Wong - One of the best experts on this subject based on the ideXlab platform.

  • soil Water Retention behavior of compacted biochar amended clay a novel landfill final cover material
    Journal of Soils and Sediments, 2017
    Co-Authors: James Tsz Fung Wong, Zhongkui Chen, Xunwen Chen, Ming Hung Wong
    Abstract:

    Biochar has long been proposed for amending agricultural soils to increase soil-Water Retention capacity and therefore promotes crop growth. Recent studies revealed the potential use of biochar-amended soil in landfill final covers to promote methane oxidation and odor reduction. However, the effects of biochar application ratio, compaction Water content (CWC), and degree of compaction (DOC) on soil-Water Retention characteristics of biochar-amended clay (BAC) at high soil suction (dry condition) are not well understood. The present study aims to overcome this knowledge gap. Soil suction was induced using vapor equilibrium technique by a temperature- and humidity-controlled chamber, and the Water desorption (drying) and adsorption (wetting) Water Retention curves (WRCs) of compacted pure kaolin clay and peanut shell BAC with different biochar application ratios (0, 5, and 20 %, w/w), DOCs (80, 90, and 100 %), and CWCs (30 and 35 %) were measured. The correlations between these factors and the gravimetric Water content were analyzed by three-way ANOVA followed by the Tukey HSD test. The soil micro-structure was studied by scanning electronic microscope with energy-dispersive X-ray spectroscopy. Measured WRCs of BAC suggest that the soil-Water Retention capacity at high suction range (48.49–124.56 MPa) was in general increased, upon biochar application. The BAC compacted with CWC of 35 % at low (80 %) and high (100 %) DOCs for the 5 % BAC were increased by 7.30 and 9.77 %, when compared with clay, while the increases of 20 % BAC were 39.89 and 59.20 %, respectively. This is attributed to the embedded effects of clay particles in biochar pores, which reduce the total pore space of BAC. The soil-Water Retention capacity of BAC was also increased with CWC and decreased with DOC. The results of three-way ANOVA analysis show that the effects of DOC and biochar ratio on soil gravimetric Water content was significant (p < 0.05) only at 48.49 MPa on drying path. For other induced suctions, only effects of CWC were significant (p < 0.05). Biochar application increases soil-Water Retention capacity of the BAC at high soil suction (48.49–124.56 MPa) (dry condition) at both low (80 %) and high DOC (100 %). The soil-Water Retention capacity of 20 % BAC was much higher than that of 5 % BAC. BAC is a potential alternative landfill final cover soil with a higher soil-Water Retention capacity to be used in dry areas or regions with a long period of evaporation event.

  • soil Water Retention behavior of compacted biochar amended clay a novel landfill final cover material
    Journal of Soils and Sediments, 2017
    Co-Authors: James Tsz Fung Wong, Zhongkui Chen, Xunwen Chen, Ming Hung Wong
    Abstract:

    Purpose Biochar has long been proposed for amending agricultural soils to increase soil-Water Retention capacity and therefore promotes crop growth. Recent studies revealed the potential use of biochar-amended soil in landfill final covers to promote methane oxidation and odor reduction. However, the effects of biochar application ratio, compaction Water content (CWC), and degree of compaction (DOC) on soil-Water Retention characteristics of biochar-amended clay (BAC) at high soil suction (dry condition) are not well understood. The present study aims to overcome this knowledge gap.