Interparticle potential and sedimentation behavior of cement suspensions

Yang, Ming; Neubauer, C.M.; Jennings, Hamlin M.

doi:10.1016/s1065-7355(97)90009-2

Cited by 25 publications

(27 citation statements)

References 3 publications

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“…There are some ideas that a lower ionic strength is associated with a better penetrability of the grout. (Yang, et al, 1997). Ions in the mixture (pore water) can be neutralized by the addition of some kind of complex binder, depending on the ion type.…”

Section: Discussionmentioning

confidence: 99%

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Penetrability due to filtration tendency of cement-based grouts

Eklund

Stille

2008

Tunnelling and Underground Space Technology

105

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ii iii SummaryGrouting as a method of strengthening and sealing rock, soil and concrete is widely used. The possibilities of sealing structures are of great importance from both an economical and environmental point of view. The cost of grouting has in certain projects been as high as the cost for the blasting and excavation of the tunnel. To improve the technique of grouting with cement based material, it is necessary to focus on the properties of the used grout mixture. The ability of a grout to penetrate cavities, channels and porous material, the penetrability, depends on two things, the theology and the filtration tendency. Extensive laboratory tests on stable, low w/cratio, injection grouts show that the most significant limitation to their penetrability is the tendency of cement grains to agglomerate into an impermeable filter cake. The properties of a grout that may prevent passing obstructions in the flow path without the cement grains clogging and preventing further penetration is in this work called filtration tendency. An inert material mixture and a cement-based mixture are used for the investigations in this work. The inert material, which is crushed dolomite stone, does not react with the added water in the mixture. The used cement grouts are based upon three types of commercial available Portland cements and four Portland cements with modified grain size distribution curves.Performed tests show that the grain size and grain size distribution is of great importance for the filtration tendency. According to performed experiments with inert and cement material, it seems to be advantageous for the penetrability to have a grain size distribution that contains neither too many fine or coarse grains. It is reasonable to believe that the grain size distribution should be relatively steep (narrow grain size range) between minimum and maximum grain size. The maximum grain size is of importance in terms of for example d 95 . Too large maximum grain size will prevent penetration of the mixture through obstructions in the flow path. According to performed tests, the value of d 95 , should be between 4-10 times smaller than the aperture to be penetrated by the cement based mixture. The small grain sizes are also of importance in order to achieve a low filtration tendency of the grout. This is because of the increased tendency for the small grains to flocculation into larger agglomerates, compared to larger grain sizes.The filtration experiments with cement based grouts show that influences of parameters like surface chemistry (use of superplastisisers) and cement chemistry (hydration of cement grains) will strongly affect the filtration tendency of the mixture.To visualize the phenomenon of filtration tendency it can be investigated on a larger scale than usually takes place. Filtration experiments in the scale of approximately 100:1 have been performed in order to see influences of grain concentration, grain shape and the penetrated slot aperture. It can be seen that used grain sizes (monodisperse and inert m...

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Section: Discussionmentioning

confidence: 99%

“…There are some ideas that a lower ionic strength is associated to a better penetrability of the grout. (Yang et al 1997). However, a low ionic strength is probably also associated with a lower reactivity of the cement.…”

Section: Pore Watermentioning

confidence: 99%

Penetrability due to filtration tendency of cement-based grouts

Eklund

Stille

2008

Tunnelling and Underground Space Technology

105

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“…Concerning mortar, data in literature obtained by zeta potential measurements with powdered CSH in dilute solutions, established the Ca 2+ ions as potential determining ions for the CSH surface [20][21][22][23]. In fact, they established that at low concentrations of Ca in solution, the zeta potential is negative, and at higher Ca + content, the zeta potential values become positive, with a point of zero charge of 2 mmol/L [23].…”

Section: Zeta Potential In the Different Systemsmentioning

confidence: 99%

“…The most numerous from cement or synthetic CSH suspensions, by the microelectrophoresis technique [12,[15][16][17][18][19][20][21][22][23][24], but also using other techniques as acoustophoresis [25], which are very important to know the basic features of the electrokinetics for these materials but are quite far of the real conditions of application of the remediation treatments, as the material is grinded and in a very diluted suspension. By the first time, the authors were able to demonstrate and quantify the electroosmotic flux through monolithic hardened carbonated concrete [26] in realkalisation tests with carbonated concrete, following in situ the experiment by neutron diffraction analysis [27], studying the influence of the external solution [28], and the composition of the binder [29].…”

Section: Introductionmentioning

confidence: 99%

Assessment of electrophoresis and electroosmosis in construction materials: effect of enhancing electrolytes and heavy metals contamination

2010

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Electrokinetic effects are those that take place by application of an electric field to porous materials, with the zeta potential as the key parameter. Specifically, in the case of contaminated construction materials, the generation of an electroosmotic flux, with the corresponding dragging due to water transport, is a crucial mechanism to succeed in the treatment of decontamination. Therefore, it is of great interest trying to optimize the treatment by the addition of specific electrolytes enhancing the electrokinetic phenomena. Most of the data of zeta potential found in literature for construction materials are based in micro-electrophoresis measurements, which are quite far of the real conditions of application of the remediation treatments. In this paper, electrophoretic and electroosmotic experiments, with monolithic and powdered material respectively, have been carried out for mortar, brick and granite clean and contaminated with Cs, Sr, Co, Cd, Cu and Pb. The electrolytes tested have been distilled water (DW), Na 2 -EDTA, oxalic acid, acetic acid and citric acid. The zeta potential values have been determined through the two different techniques and the results compared and critically analysed.

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“…After the accelerated aging cycles, all formulations displayed increased bulk density; this fact is related to the hydration of the cementitious matrix that takes place over exposition to water and natural carbonation during the aging cycles, as Portland cement is a hydraulic binder consisting of silicate and calcium aluminates. The continuous availability of water that takes place with aging favors the development of silicate hydrates and calcium aluminates, benefiting the densification of the cementitious material [39][40][41] . Almeida et al…”

Section: Analysis Of the Resultsmentioning

confidence: 99%

Cellulose Associated with Pet Bottle Waste in Cement Based Composites

et al. 2017

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The present study was to evaluate the effect of polyethylene terephthalate (PET) particle sizes on the mechanical and physical properties of extruded fiber-cement composites with different particle sizes combined to cellulose pulp in the production of fiber cement by the extrusion process. The design consisted of four formulations, one composed of 5% cellulose and the other three with 2.5% cellulosic pulp and 2.5% of PET particles with different particle sizes. Physical, mechanical and microstructural tests were performed without aging cycles and after 200 and 400 accelerated aging cycles. The degradation of vegetable fibers in the cement and the decrease of properties with aging was observed. PET particles were more resistant in alkaline environment and did not degrade. However, particle size did not exert great effect in the physical and mechanical properties of the composite. Thus, the use of PET particles shows potential as a reinforcement for fiber-cement composites.

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Interparticle potential and sedimentation behavior of cement suspensions

Cited by 25 publications

References 3 publications

Penetrability due to filtration tendency of cement-based grouts

Penetrability due to filtration tendency of cement-based grouts

Assessment of electrophoresis and electroosmosis in construction materials: effect of enhancing electrolytes and heavy metals contamination

Cellulose Associated with Pet Bottle Waste in Cement Based Composites

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