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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"Sorptivity"”.
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Accelerating and automating sorptivity measurements in cementitious systems via computer vision
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01
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Evaluating reactivity and sorptivity of fly ash for use in concrete construction
This thesis describes research carried out to investigate techniques for (i) rapidly assessing the reactivity of fly ash; and (ii) evaluating its interaction with air-entraining admixtures (AEAs), both with regard to use in concrete. The materials considered for the project included, 54 fly ashes …
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An investigation of concrete curing practice in the Cape Town area
… sites. The oxygen permeability and water sorptivity tests were used to investigate the outer surface of concrete. The laboratory work showed that curing at a relative humidity of 90 had a beneficial effect on the durability index values, while curing at 60 relative humidity was less …
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The durability of fly ash concrete in marine and softwater environments
… concrete were tested for compressive strength, sorptivity (rate of water absorption) and density. At the same time, fly ash and OPC concrete samples were exposed to the marine and softwater environment for up to 10 months. Marine exposure was done in the submerged, tidal and spray zones in Table …
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Influence of near surface moisture gradients in concrete on 'Autoclam' permeation measurements
… the concrete on 'Autoclam' air permeability and sorptivity measurements. An analysis of the results indicated a unique relationship between the air permeability and the relative humidity recorded in a 10 mm deep drilled hole. A linear relationship was found between the sorptivity and the relative …
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Rheology of grout for preplaced aggregate concrete. Investigation on the effect of different materials on the rheology of Portland cement based grouts and their role in the production of preplaced aggregate concrete.
… then produced and their compressive strength and sorptivity were tested. Grout rheology can be defined by the rheology of cement paste employed and the internal distance between sand particles. The effect of sand surface texture on grout rheology is important at very low internal distances. Fresh …
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The mechanisms of moisture ingress & migration in rammed earth walls.
… is used to define the parameter S, known as sorptivity. Static pressure-driven moisture ingress occurs at a rate that is significantly higher than S, and it does not obey the extended Darcy equation. The effective hydraulic pore radius (r) of rammed earth is typically very small which …
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Practical implementation of the durability index-based performance approach
… (oxygen permeability index (OPI), water sorptivity index (WSI) or chloride conductivity index (CCI)) and cover depth, depending on exposure conditions for a given service life. These specifications have been implemented by the South African National Roads Agency Limited (SANRAL) in major …
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The influence of crystalline admixtures on the mechanical and durability properties of cracked and uncracked concrete
… all concrete mixes showed “good” quality with sorptivity values at curing ages 4, 8, and 12 weeks except concretes with w/b of 0.4 at 12 weeks with excellent quality. The sorptivity values were deduced to decrease with an increase in curing age due to the continuing hydration which refined the …
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Infiltration controls in a tallgrass prairie at a hillslope scale
… were used to extract hydraulic conductivity and sorptivity values from the infiltration data. Next, large intact soil cores were extracted from three selected sites at the same hillslope and analyzed at six depths using a large disk infiltrometer. Finally, the six segments of the large soil cores …
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Additive Manufacturing of lignocellulosic composites for riverine resilience
… sites subject to flooding? We lack knowledge on sorptivity properties or size increase implications on material functionalities. Advancing our understanding of mechanic-structure interdependence and size increase effects is critical to overcoming scalability hurdles essential for exterior …
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Evaluation of lateritic coarse aggregates as a partial replacement for granite coarse aggregates in structural concrete.
… durability properties of the concrete such as Sorptivity, water accessible porosity and residual strength after exposure to high temperature. Mineral composition of Lateritic Coarse Aggregates was analyzed using X-Ray Diffraction (XRD). The results showed that crushed lateritic aggregates were …
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Evaluation of lateritic coarse aggregates as a partial replacement for granite coarse aggregates in structural concrete.
… durability properties of the concrete such as Sorptivity, water accessible porosity and residual strength after exposure to high temperature. Mineral composition of Lateritic Coarse Aggregates was analyzed using X-Ray Diffraction (XRD). The results showed that crushed lateritic aggregates were …
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Freeze-Thaw Resistance and Microstructural Characteristics of Concretes Containing Pozzolans
… porosity. There is a strong correlation between sorptivity and pore refinement. Increasing amounts of the MK appear to cause refinemenent of the concrete's pore structure. As a result of this pore refinement sorptivity decreases with increasing amounts of MK. In addition blending FA with MK …
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Critical review of the South African Concrete Durability Index tests
… are the oxygen permeability index (OPI), water sorptivity index (WSI), and chloride conductivity index (CCI) tests, respectively. Much work has been done over the past two decades in developing the DI tests to the present stage, where they are being, and have been, used in large projects such as …
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The Durability of Mortar with Ground Clay Brick as Partial Cement Replacement
… Compressive strength, pore size distribution and sorptivity of mortar generally all benefit from the presence of ground brick and the greatest effect can be seen after water curing for one year. Compressive strength of concrete is also shown to increase as the fineness of ground brick increases …
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Crack Self-Healing in Alkali-Activated Materials: From Mechanisms to Strategies for Enhancing the Healing Efficiency
… microscopy, compressive and tensile tests, sorptivity tests, mercury intrusion porosimetry (MIP), inductively coupled plasma optical emission spectroscopy (ICP-OES), and X-ray microcomputed tomography (μCT). Crack self-healing products were characterized using scanning electron microscopy …
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Optimizing the usage of fly ash in concrete mixes
… better results for Oxygen Permeability Index and Sorptivity Index, with the 40% FA mix following closely. The higher FA content mixes (50% and 60%) attained better Chloride Conductivity results than the lower FA content mixes. Increasing the FA content does affect the performance of the concrete …
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The impact of bacteria on the biophysics of water retention and flow in soil
… from -1 cm to -100 cm during two wet-dry cycles. Sorptivity (S, mm s-1/2) of the soil, indicative of water repellency, was determined using a mini-infiltrometer setup and has been reported as the rate of infiltration of water into the soil. Bacteria have been shown to increase water repellency of …
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Ternary combination concretes using GGBS, fly ash & limestone: strength, permeation & durability properties
… (absorption (initial surface absorption and sorptivity) and permeability (water penetration and air permeability)) and durability properties (accelerated carbonation and chloride ingress) of the test concrete were also investigated. At 28 days, for low GGBS levels, the binary concretes gave …
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