STUDY ON COMPRESSIVE STRENGTH OF CONCRETE …
These various specimens of fly ash and nanosilica cement concrete are to be tested 7 days, 14 days and 28 days to find compressive strength and also analyze through SEM.
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Fly ash and slag
The amount of fly ash in mortar or concrete can thus be increased. Other features such as tightness, permeability to chloride ions, etc. are also improved. According to the author, in case of an industrial scale, finer milling of cement clinker (cement) is more preferable solution for the production of fly ash cement than grinding fly ash.
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Effect of fly ash on the service life, carbon footprint and embodied
The most common binder of traditional concrete is Portland cement. Cement production needs high temperature calcination which is an energy intensive process and causes approximately 5–7% of man-made CO 2 emissions globally [1], [2].The global cement production is expected to increase from 3.27 billion metric tons in 2010 to 4.83 billion metric tons in 2030 [3].
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Performance of high volume fly ash concrete
The compressive strength of HVFA concrete has been reported to decreased as the percentage cement replacement increased, Table 1. ... The early age performance of HVFA concrete is significantly impaired by the replacement of the cement with fly ash. Several methods have been investigated to achieve increased cement replacement levels without ...
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Comparison of fly ash and rice husk ash effects on the …
1.1.1. Specifications. The UK national standards for highways, for example, have developed a design chart for estimating the concrete thickness layer of RCC pavements …
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(PDF) MECHANICAL PROPERTIES OF HIGH-VOLUME FLY ASH CONCRETE …
shows the variations in compressive strength of concrete with various percentages of FA at 3, 7, and 28 days. For FA0, the compressive strength increased from 18.6 MPa to 24.0 MPa, and 42.6 MPa ...
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Fresh and Microstructural Properties of High-Volume Fly Ash …
Waste disposal has arisen as a serious global issue for nations worldwide. Fly Ash (FA) is one such waste substance that is created as a residual of coal combustion obtained from thermal power plants [].With diminishing raw material supplies and an urgent need for environmental preservation, there is a pressing need for the development of novel construction …
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Effect of fly ash and GGBS on strength and durability of …
Fly Ash and GGBS is used to make durable concrete structures in combination with ordinary Portland-cement and/or other pozzalanic materials. Cubes are tested for its compressive …
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Self-consolidating concrete using recycled concrete aggregate …
The following paths of concrete production sustainability were identified: mix composition (e.g. reduce the EI and resources use of binders, aggregates, water and reinforcement), materials manufacturing (e.g. new production techniques of cement, aggregates and steel bars), concrete mixing (e.g. mixer type and mixing method), on-site application ...
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Chapter 3
Fly ash use in concrete improves the workability of plastic concrete, and the strength and durability of hardened concrete. Fly ash use is also cost effective. When fly ash is added to concrete, the amount of portland cement may be reduced.
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INFLUENCE OF FLY ASH ON THE COMPRESSIVE …
cement and fly ash, which was obtained with X-ray Fluorescence (XRF) analyses. As it is possible to see, the composition of this fly ash is rich in Si and Al oxides, with few quantities of calcium oxide. Tab. 1: Chemical compounds in Portland cement and fly ash. Compound Cement (wt %) Fly ash (wt %) Al 2 O 3 3.772 32.242 SiO 2 14.317 53.640 SO 3
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Experimental Study on Use of Fly Ash in Concrete
To study the use of fly ash in concrete, cement is replaced partially by fly ash in concrete. In this experimental work concrete mix prepared with replacement of fly ash by 0%, 25%, 50%, 75% and .
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Experimental investigation of compressive strength for fly ash on …
However, the compressive strength of concrete at the age of 28 days with partial replacement of fly ash shown improvement up to 10% by about 2.42% and 3.89% but, beyond 10% replacement of fly ash by cement the mean compressive strength shows that reduction by about 0.69%, 0.71%, 8.35% and 16.03% over the control sample respectively, due to ...
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Fly Ash Concrete: A Technical Analysis for Compressive …
containing 10 % of fly ash, related to cement mass, gained a compressive strength about 6 % higher than the concrete addition for Ordinary Portland cement. For fly ash blends greater than …
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Role of Fly Ash in Concrete Construction Industry
the silicate to hydroxide ratio of the used activator impacts how fly ash-based geopoly-mer concrete, its flowing ability, and initial, and final compressive strength. It is well-noted that fly ash GPC generates the majority of its strength within 1-week of being poured. On the contrary, fly ash portland cement concrete may face compressive
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Early age strength increase of fly ash blended cement by a …
Several studies show that compressive strength of OPC-FA can be enhanced by addition of certain chemicals. Jueshi et al. [16] found that the addition of 3% sodium sulfate (Na 2 SO 4) as dry weight by mass of total binder increased the compressive strength of an OPC-FA binder with 30% OPC replacement by almost 50% at the ages of 3 days and 28 days. Lee et …
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Concrete Applications Using High-Carbon Fly Ash
Fly ash has long been used as an admixture for concrete. Utilization of fly ash material in concrete turns a coal combustion by-product into a useful material reducing energy needed to produce concrete, reducing the use of portland cement in the mix, and improving the workability of concrete without dramatic changes to the rate of set and/or early strength.
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Use of Fly Ash and Slag in Concrete: A Best Practice Guide
The strength development of fly ash concrete is strongly affected by the type of fly ash and ... as has been reported in several published technical . ... (up to 28 days) as a portland cement ...
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(PDF) Compressive strength, flexural strength, and durability of …
The utilization of class F fly ash (F-FA) is limited to 15–30% as a substitution for cement. The study intends to tap into the potential of high-volume F-FA as a pozzolan and micro filler by ...
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Improvement of the early and final compressive strength of fly ash
Sustainable concrete has reduced CO 2 emissions, is durable, and is expected to have less detrimental effect on future generations, due to the fact that it utilizes waste materials. However, the need for external heat limits construction applications. The effects of sodium hydroxide ratio, external heat amount, and partial Portland cement replacement on fly ash …
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Development and optimization of geopolymer concrete with …
Fly ash-based geopolymer concrete (FA-GPC) is a material that might be utilized to build a more sustainable construction industry; therefore, this paper aims to develop a novel …
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Performance investigation of high-proportion Saudi-fly-ash-based concrete
This by-product is called fly ash (FA) or pulverized fuel ash in the UK [24]. FA is a coal incineration application that comprises fine particles of fuel obtained from coal-fired boilers and flue gases, and is used as SCM, thereby reducing the utilization of cement in concrete and decreasing the CO 2 emissions and energy exhaustion [25, 26].
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Frost resistance of concrete with high contents of fly ash
The concrete mixtures with high contents of fly ash were designed to have 28 days compressive strength comparable to a frost resistant reference mixture, which had a much lower fly ash content. Therefore, the W/B was not fixed; the slower property development of mixtures with high fly ash contents was compensated by lowering the W/B.
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The Early Age Strength Improvement of the High Volume Fly Ash …
According to several reports, cement manufacture is one of the largest sources of carbon dioxide in the concrete sector. ... properties beyond 28 days. The reactivity of fly ash [500 µm] is ...
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Best Practices Guide for High-Volume Fly Ash Concretes
HVFA concrete formulation in which 50 % of the portland cement is replaced with fly ash on a mass basis [6], providing "constructability, cost-effectiveness, and environmental benefits." …
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Durability assessment of fly ash, GGBS, and silica fume based
Concrete is a very adaptable building material with minimal maintenance requirements over its service life. However, the durability of ordinary Portland cement (OPC) concrete is susceptible when exposed to aggressive environments [1], raising concerns about its resilience against chemical attacks, particularly from acids and sulfates [2].
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Optimizing the use of fly ash in concrete
In this connection, researchers have carried out investigations on effective utilization of fly ash in cement manufacturing, manufacture of concrete/autoclaved aerated concrete (AAC) blocks ...
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Relation between the compressive strength and age of fly ash as …
Several materials including biomass ash have been proposed as a sustainable alternative to fly ash in the production of concrete. ... A research using 30% fly ash in cement increased the concrete ...
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Hydration and physical characteristics of ultrahigh-volume fly ash
Replacing cement by fly ash in concrete brings several benefits. ... However, the long-term (after 90 days) compressive strength of FA60 is comparable to that of FA40, which is a result of the pozzolanic reaction of fly ash. In addition, FA80 can still achieve more than 40 MPa at 7-day age, over 60 MPa at 28-day age, more than 70 MPa at 90-day ...
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Comparative study on compressive strength of fly ash concrete
The concrete mix is prepared by varying the proportions of fly ash for 30%, 40% and 50% of cubes and prisms cured in normal water for up to 28 days and the properties like Slump cone test ...
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Development of sustainable lightweight concrete using fly ash
Hence, it may be inferred that though the compressive strength of concrete mixes at 7, 28 and 90 days are less than that of control concrete mix (CS-00) except 7 day compressive strength of concrete mixes with SFA (CS-03), the strength of concrete mixes decreases for the use of 50% SFA and thereafter, increases with the increase in the SFA ...
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Contribution of Fly ash to the properties of Mortar and …
These results are similar to those of Siddique (2003) who reported that, when fly ash was used as an addition of cement (i.e. 28% by weight of cement) in concrete, there was a 23% gain in strength ...
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Concrete incorporating supplementary cementitious materials: …
A combined effect of fly ash and silica fume can also be achieved with proper mix proportions. For instance, a concrete mix with 10 % fly ash and 10 % silica fume resulted in a compressive strength of 48 MPa at a 7-day curing age and above 63 MPa at a 28-day curing age [24].This is possible by reducing the water-binder ratio (w/b) to get the desired strength and …
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Fly ash concrete ppt | PPT
The compressive strength at 7, 14, 21, and 28 days with 20% replacement was found to compare favorably to concrete without replacement. ... and chemical composition of fly ash, as well as its reactions in cement. It describes several current and potential applications of fly ash in Sri Lanka, including in concrete, bricks, blocks, and road ...
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