penetrometer to test the strength gain versus the time of setting. Additionally, the fly ash–soil mixture has a time of setting that is slightly different from that of fly ash itself. The time of setting of fly ash–soil mixtures directly relates to the compaction delay (Misra 1998; Mackiewicz and Ferguson 2005; Senol et al. 2006).
Keyw ords: high -calcium fly ash, geopolymer paste, setting time, compressive strength. Abstract . Fly ash based geopolymer normally gets the optimum strength by heat curing.
Download scientific diagram | The initial and setting time of various fly ash for geopolymer. from publication: Characteristics of Fly Ash as a Constituent Material for Geopolymer | Fly ash waste ...
Anti-crack performance of concrete with phosphorus slag and fly ash singly and compositely added is investigated in terms of physical performance, hydration heat, dry shrinkage and creep, and ...
1 The Relationships between Setting Time and Early Age Strength of Concrete containing Silica fume, Fly ash and Slag Mahmoud Nili1, Mohsen Tadayon 2, Mojtaba Nili3 1Associate Professor, Civil Eng., Dept., Bu-Ali Sina University Hamedan I.R..Iran 2Assistant Professor, Civil Eng., Dept., Bu-Ali Sina University Hamedan I.R..Iran 3Msc, Civil Eng., Dept., Bu-Ali Sina University …
The results show that with smaller fly ash particles size and higher levels of fly ash replacement, the workability of the mixture was increased with longer setting time. There was an increase in mortar compressive strength with finer fly ash particle size, compared to those with unclassified ones, with the highest strength was found at those ...
Accelerators are used in cementitious materials for augmenting the rate of early age strength and/or abbreviating the time of setting for the fill to pass from plastic to solid state [55, 56].They are widely used to obtain high early strengths in sprayed concrete applications, providing setting start in a short time and eliminating rebound problem [[57], [58], [59]].
The Moroccan cement industry is looking for new processes to effectively minimize the high energy costs associated to cement manufacturing. This work presents the effect of three types of limestone with different chemical compositions and different CaCO3 contents on the physical and mechanical properties of resulting composite cements by the addition of fly ash in the …
According to the results, they introduced fuzzy logic approaches that establish correlation among cement's setting time, the silica fume and fly ash [30]. Tanyildizi investigated a fuzzy logic ...
However, I've heard that fly ash retards setting, which would be undesirable when using the mix in cool weather. Is it possible to add fly ash without affecting the concrete setting time? Fly ash doesn't chemically retard setting. But many times fly ash is used in concrete as a cement replacement in combination with a water reducer.
This research investigates the setting time and workability of geopolymerized fly ash-phosphogypsum paste (GPP) and mortar (GPM) using a Vicat needle procedure per ASTM …
The problem of rapid or short setting time has been reported by many researchers when utilizing high calcium fly ash as an aluminosilicate source material in the synthesis of geopolymers.
The input data required for the model are water-cementitious material ratio, fineness, specific gravity, temperature, and the blended oxide ratio: CaO/(SiO2 + Al2O3 + …
Geopolymer is produced from the alkali activation of materials rich in Si and Al such as fly ash. Sodium hydroxide (NaOH) with high concentration is normally used in geopolymerization. Limited research has been done with low concentration of alkali activator. This study confirms that KOH with low concentration affect the setting time and compressive …
The results show that as the temperature increases, the initial and final setting times decrease for all types of concrete, with fly-ash concrete having the longest setting …
Electrical resistance (or heat flow) measurements can be used to adequately predict a mixture's initial setting time for a wide variety of binary and ternary powder blends, …
Strength and Setting Times of F-Type Fly Ash-Based Geopolymer Mortar International Journal of Earth Sciences and Engineering ISSN 0974-5904, Vol. 09, No. 03, June, 2016, pp. 360-365
The first experiment tests the strength of cement mixtures with different ratios of cement, sand, lime, fly ash and rice husk after 3 days. The second experiment tests the strength of three cement mixtures over time at 3, 10, and 20 days. ... Effect of time on setting of cement mortar. Time has an important role on the strength developed by ...
of Fly Ash‑Based Geopolymer Mixture Containing Slag K. M. Prasanna 1 · B. P. Sharath 1 · Himanshu Choukade 1 · K. N. Shivaprasad 2 · B. B. Das 1 · Gangadhar Mahesh 1
Using Test Method for Time of Setting of Concrete Mixtures Paste by Penetration Resistance (ASTM C 403), Proctor penetration resistance was determined under isothermal curing temperatures ranging from 6 to 80°C for concretes containing up to 50% of fly ash or ground-granulated blast-furnace slag.
(a) Setting time of cement pastes with seven dosage of accelerator and (b) setting time of cement pastes with three w/b and four amount of fly ash. Source publication +15
Zheng et al. investigated the rheological properties of Portland-fly ash cement paste containing a high volume of FBC fly ash and found that when the FBC fly ash content exceeded 50% by …
The activator type and concentration have a significant influence on the initial and final setting times of alkali activated GGBS/fly ash concretes. Nath and Sarker [4] evaluated the effect of increasing the alkaline activator contents and ratios on the setting time of alkali-activated GGBS/fly ash concretes and mortars. It was found that ...
This research systematically investigated the effects of fly ash (FA) in magnesium ammonium phosphate cement (MAPC) on the fluidity, setting time, compressive strength, and water resistance.
The findings demonstrated that the CaO level in the fly ash impacted the setting time, with those with a CaO content of less than 10% taking a longer time to set, while those with more than 10%...
Magnesium silicon potassium phosphate cement (MSPPC), a new magnesium phosphate cement of the MgO-SiO2-K2HPO4 system, can possess higher strength, longer setting time, and better fluidity than the ...
The coagulation structure Si–OH and Al–OH was formed due to the reaction of Ca(OH) 2 with Si + and Al + in CFBC fly ash. The main hydration products of the CFBC fly ash and coal-fired fly ash are C–S–H and C–A–H gels. ... Effect of fineness and content of fly ash on setting time of Portland cement. Cement, 12 (2003), pp. 4-6. Google ...
56 days to identify the strength development of each sample. The result revealed that the content of CaO in fly ash affected the setting time and early strength development. In three days paste …
Title: Prediction of Setting Time of Fly Ash Concrete Author(s): J. J. Brooks Publication: Materials Journal Volume: 99 Issue: 6 Appears on pages(s): 591-597 Keywords: concrete; factors; fly ash; penetration; prediction; setting time DOI: 10.14359/12369 Date: 11/1/2002 Abstract: A model for predicting the initial setting time of concrete with and without …
For the time of setting property, ASTM recommends a water-to-ash weight ratio of 0.35 and a test by Vicat needle in accordance with the test method ASTM C191 (2008).
The setting time results indicate that when the cement composition consists of only 30 % G oil well cement and a large proportion of fly ash(65 %∼70 %), the setting time is prolonged, especially at low curing temperature (3°C,10°C). On the other hand, with a high proportion of fly ash, the early compressive strength is quite low.
fly ash slightly retards the setting time of concrete. It was also found that the rate of strength development at various ages is related to the w/c ratio and percentages of fly ash in the concrete mix. Moreover, the modulus of elasticity of fly ash concrete also reduced with the increase in fly ash percentage for a given w/c ratio. 2.
Portland cement addition, fly ash content and solution resting time were studied.. The study focused on curing temperature and curing period. • Performance and mechanical properties of GPC were evaluated for all factors.. Portland cement addition up to 15% improves GPC properties except workability.. Solution resting time for 30 min yields higher performance.
Therefore, the hydration rate of cement is decreased with the increasing dosages of fly ash, leading eventually to increasing the setting time, as observed in Figure 4, and relationships between ...
The early strength of the geopolymer formed by the incorporation of GGBS in fly ash was improved and the setting time was ... the overall initial and final coagulation times were relatively long in Group A and shorter in Group C. ... all COSGM samples in Table 4 meet the requirements of fluidity and setting time of cement (GB175–2023), and ...
PDF | On Jun 15, 2024, Jabulani Matsimbe and others published Setting Time and Workability of Geopolymerized Fly Ash- Phosphogypsum Paste and Mortar | Find, read and cite all the research you need ...
The setting time of MKPC was determined using a Vickers meter, and the initial setting time was taken as the final setting time. The Chinese standards GB/T 1346, "Test Methods for Water Consumption, Setting Time, and Stability of Standard Consistency of Cement," and JC/T 2537–2019, "Magnesium Phosphate Repair Mortar," were consulted for ...
setting time and workability. It was found that an increase in the PG wt% led to a decrease and/or acceleration in the initial setting time (INSET) and final setting time (FINSET) attributed to the rapid dissolution of Ca. 2+ in low alkaline concentrations outnumbering that of Al. 3+ and Si. 4+
Fly ash The fly ash used in this test was secondary and had a dark gray color. The chemical composition of fly ash is shown in Table 2. Metakaolin The metakaolin used in this test was brick red ...