An investigation of rheological properties of cement-based grout mixed with rice husk ash (RHA)
TL;DR: In this article, the fluidity and rheological properties of the cement-based grout mixed with rice husk ash (RHA) were investigated, and it was shown that increasing replacement level for the RHA amount increases marsh cone flow time, plate cohesion, plastic and apparent viscosity, and the yield stress, but also decreases mini slump diameter.
About: This article is published in Construction and Building Materials.The article was published on 2015-08-30. It has received 112 citations till now. The article focuses on the topics: Apparent viscosity.
Citations
More filters
TL;DR: In this article, the authors present an overview of some of the published results on the successful utilization of rice husk ash as a supplementary cementitious material and the properties of such concrete at fresh and hardened stages.
Abstract: The production of cement depletes natural resources, consumes high energy and emits huge amounts of green house gases. It accounts for almost 7% of the global carbon dioxide emissions, as the production of one ton of ordinary Portland cement releases approximately one ton of carbon dioxide. Due to the severe environmental pollution and health hazards associated with the cement and construction industries, they are under the strict scrutiny from the governments and environmentalists. Rice husk is an agricultural waste, whose natural degradation is restricted due to the irregular abrasive surface and high siliceous composition. It is not appropriate to be used as a feed for animals due to the low nutritional values. If dumped as landfill, they can take a lot of area and become a major challenge to the environment. If they are disposed by burning, the ashes can spread to the surrounding areas, create pollution and destroy the natural beauty. One of the possible solutions for the disposal of rice husk is to convert them into rice husk ash and incorporate them into cement based materials. The partial inclusion of rice husk ash (RHA) for cement is found to be durable, environmental friendly and economically viable. This paper presents an overview of some of the published results on the successful utilization of rice husk ash as a supplementary cementitious material and the properties of such concrete at fresh and hardened stages. Studies indicate that there is a promising future for the use of rice husk ash in normal, high strength and self compacting concrete as it shows high strength, low shrinkage and permeability, high resistance to carbonation, chloride, sulfate and acidic environments. The summery and discussions provided in this paper should provide new information and knowledge on the applications of greener and sustainable rice husk ash concrete.
147 citations
TL;DR: In this article, a simple and economical additive, fly ash, is investigated to improve the rheological properties of cement paste when GO is present, based on the quantitative analysis of the Rheological parameters, it was shown that fly ash can offset the reduction of fluidity by GO.
135 citations
TL;DR: In this paper, the ASTM Type I Portland cement (PC), class F fly ash (FA), bentonite (B), superplasticizer (SP) and water glass were designed to improve properties of grouting materials in different aspects.
95 citations
TL;DR: In this article, the effects of adding RHA and ordinary Portland cement on the geotechnical properties of the clayey sand sampled from the Sejzi area, which lies east of the city of Isfahan, Iran.
Abstract: Highway construction and maintenance are usually expensive, and cost control efficiency is imperative. Although there are several stabilization methods, soil stabilization with agricultural waste materials, such as rice husk ash (RHA), is among the most eco-friendly and affordable methods. The aim of this study is to experimentally investigate the effects of adding RHA and ordinary Portland cement on the geotechnical properties of the clayey sand sampled from the Sejzi area, which lies east of the city of Isfahan, Iran. First, the oxide compounds of RHA, cement, and soil were determined using the X-ray fluorescence (XRF) test. Five different compounds of the soil with 2, 4, 6, and 8% of cement were mixed, and, later, different percentages of RHA (0, 2, 4, 6, and 8%) were added to determine the unconfined compressive strength (UCS), California bearing ratio (CBR), optimum moisture content (ω opt ), and maximum dry density (γ d ) of the stabilized soil compounds with 7, 14, and 28 curing days. The results showed that by increasing the content of RHA, the ω opt of the specimens increased, while the γ d decreased. The 28-day-cured specimen with 6% RHA and 8% cement showed the highest values of UCS and CBR at 25.44 and 18.2 times more than those of the values for untreated soil, respectively. The scanning electron micrograph (SEM) test of the aforementioned stabilized soil was characterized as a well-structured soil matrix with very small pores, which can be attributed to the pozzolanic reactions of the cement and RHA. The effectiveness, abundance, and the low cost of RHA will attract considerable environmental interest in this research.
90 citations
TL;DR: In this paper, the incorporation of nano graphite platelets (NGPs) to the 3D printed geopolymer with 1% of NGPs increased the flexural strength by 89% and 46% compared to the same 3D-printed and casted geopolymers without any NGPs, respectively.
83 citations
References
More filters
Book•
26 Sep 2005
TL;DR: Concrete: Microstructure, Properties, and Materials as mentioned in this paper provides complete details on the microstructure-property relationship approach to provide scientific explanation for the strength and durability of concrete.
Abstract: Comprehensive, up-to-date coverage of the properties, behavior, and technology of concrete Fully revised to include the latest advances in concrete technology, Concrete: Microstructure, Properties, and Materials provides complete details on the microstructure-property relationship approach to provide scientific explanation for the strength and durability of concrete. This in-depth resource discusses the microstructure and properties of hardened concrete; concrete-making materials and concrete processing; and current developments in concrete technology, mechanics, and nondestructive testing methods. New to this Edition Inclusion of recently built/ongoing construction projects worldwide Information on shrinkage-reducing admixtures Coverage of the latest advances in concrete technology-self-consolidating concrete; nanotechnology of concrete; shotcrete; expansive cement; and concrete for nuclear radiation Details on modeling of ice formation and alkali-aggregate reaction in concrete 1,000 PowerPoint slides and videos that illustrate topics presented in the book
3,730 citations
"An investigation of rheological pro..." refers background in this paper
...A huge amount of amorphous silica content is obtained from non-crystalline RHA [19,20]....
[...]
TL;DR: Slip occurs in the flow of two-phase systems because of the displacement of the disperse phase away from solid boundaries as mentioned in this paper, which arises from steric, hydrodynamic, viscoelastic and chemical forces and constraints acting on the dispersed phase immediately adjacent to the walls.
Abstract: Slip occurs in the flow of two-phase systems because of the displacement of the disperse phase away from solid boundaries. This arises from steric, hydrodynamic, viscoelastic and chemical forces and constraints acting on the disperse phase immediately adjacent to the walls. The enrichment of the boundary near the wall with the continuous (and usually low-viscosity) phase means that any flow of the fluid over the boundary is easier because of the lubrication effect. Because this effect is usually confined to a very narrow layer — with typical thickness of 0.1–10 μm—it so resembles the slip of solids over surfaces that it has historically been given the same terminology. The restoring force for all the forces that cause an increase in concentration is usually osmotic, and this will always limit the effective slip. In dilute systems, concentration gradients can be present over relatively large distances out from walls, giving what might be interpreted on an overall basis as a thick solvent-only layer. However, as the concentration of the system increases, the layer gets thinner and thinner because it is more difficult to create with the large reverse osmotic force present. However, the enormous increase in the bulk viscosity with increase in concentration means that although thinner, the layer becomes, paradoxically, even more important. Slip manifests itself in such a way that viscosity measured in different size geometries gives different answers if calculated the normal way — in particular the apparent viscosity decreases with decrease in geometry size (e.g. tube radius). Also, in single flow curves unexpected lower Newtonian plateaus are sometimes seen, with an apparent yield stress at even lower stresses. Sudden breaks in the flow curve can also be seen. Large particles as the disperse phase (remember flocs are large particles), with a large dependence of viscosity on the concentration of the dispersed phase are the circumstances which can give slip, especially if coupled with smooth walls and small flow dimensions. The effect is usually greatest at low speeds/flow rates. When the viscometer walls and particles carry like electrostatic charges and the continuous phase is electrically conducted, slip can be assumed. In many cases we need to characterise the slip effects seen in viscometers because they will also be seen in flow in smooth pipes and condults in manufacturing plants. This is usually done by relating the wall shear stress to a slip velocity using a power-law relationship. When the bulk flow has also been characterized, the flow in real situations can be calculated. To characterise slip, it is necessary to change the size of the geometry, and the results extrapolated to very large size to extract unambigouos bulk-flow and slip data respectively. A number of mathematical manipulations are necessary to retrieve these data. We can make attempts to eliminate slip by altering the physical or chemical character of the walls. This is usually done physically by roughening or profiling, but in the extreme, a vane can be used. This latter geometry has the advantage of being easy to make and clean. In either case—by extrapolation or elimination—we end up with the bulk flow properties. This is important in situations where we are trying to understand the microstructure/flow interactions.
818 citations
"An investigation of rheological pro..." refers background in this paper
...During these calculation some of the researchers included slippage at low shear rate [42–44]....
[...]
TL;DR: The change in viscosity that occurs when colloidal fluids experience shear stress has been studied in this article, where the authors identify a number of materials whose rheology changes due to the shear stresses.
Abstract: Shampoos, paints, cements, and soft body armor that stiffens under impact are just a few of the materials whose rheology is due to the change in viscosity that occurs when colloidal fluids experience shear stress.
777 citations
"An investigation of rheological pro..." refers background in this paper
...The difficulty of particles flowing around each other leads to a higher rate of energy dissipation and increase in apparent viscosity [53]....
[...]
[...]
01 Jan 2016
TL;DR: New York City, one of the most populous and ethnically diverse cities in the world, has responded to a variety of enviornmental challenges in its history, including climate change as discussed by the authors.
Abstract: New York City, one of the most populous and ethnically diverse cities in the world, has responded to a variety of enviornmental challenges in its history. The most recent is climate change, which is projected to have wide impacts on the city's critical infrastructure and population through higher temperatures, more intense flooding events and sea level rise. The city recognized the risks early and has become a national and international leader in responding to this new challenge, illustrating how this is possible for a large city. As part of a mature urban region, it is an excellent bellwether for the impacts that may be experienced by other cities, especially those in emerging metropolitan conurbations.
664 citations
TL;DR: In this paper, rheological tests on cement paste were used to successfully select the type and dosage of mineral admixtures that improved concrete workability, and the conclusion reached based on the cement paste tests were validated by concrete slump tests.
561 citations