Setting times of Portland cement–metakaolin–fly ash blends
Abstract In the present study two pozzolanic materials are used, Metakaolin (MK) and Fly Ash (PFA), as binary and ternary partial replacement binders with Portland cement (PC) to investigate their effect on standard consistence and setting times of paste. To maintain standard consistency for MK–PC pastes increasing w/b ratios are required with increasing MK …
Factors influencing strength and setting time of fly ash …
Factors influencing strength and setting time of fly ash based-geopolymer paste Adhitya Leonard Wijaya1,*, Januarti Jaya Ekaputri1,2,*, and Triwulan1 1ITS Surabaya, ... The problem of application of fly ash in geopolymer concrete is the fact that every fly ash from each power plant has different characteristics. It causes a problem to control
Modified Time of Setting Test for Fly Ash Paste and …
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).
(PDF) Setting Time, Strength, and Bond of High-Calcium Fly Ash
Setting Time, Strength, and Bond of High-Calcium Fly Ash Geopolymer Concrete ... [email protected] Abstract Geopolymer concrete with low calcium oxide fly ash occurs long enough hardening time. This study aims to influence the use of CaO in gypsum, lime and carbide waste in the testing of setting the time on geopolymer and conventional paste ...
Performance analysis of self compacting concrete by incorporating fly
The provided compressive strength data show that, during 28 days of curing, the pozzolanic reactions between cement and fly ash, coal gangue, cement kiln dust, and recycled concrete powder have further progressed as shown in Fig. 11. SEM after 28 days of curing, fly ash, demonstrates how the C-S-H, C-H, and other agglutinates are evenly ...
Best Practices Guide for High-Volume Fly Ash Concretes
the timeframe typically used with OPC concrete to provide additional time for the cement and fly ash reactions to occur, which will further densify and strengthen the concrete mixture. ... the …
Detecting the Presence of Fly Ash in Fresh Concrete
Copies of the procedure, "Method of Test for Determining if Fly Ash Is Present in Plastic Portland Cement Concrete or Portland Cement," Materials Instructional Memorandum 371, are available from the Office of Materials, Iowa Department of Transportation, 800 Lincoln Way, Ames, Iowa 50010.
Fly ash for sustainable construction: A review of fly ash …
The study examined both C and F class FA and found that the initial setting time varied from 20 min to 260 min, while the final setting time varied from 60 min to 315 min, …
Effect of cement addition, solution resting time and curing
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.
Setting Time, Strength, and Bond of High-Calcium Fly Ash …
AbstractIn this paper, setting time, strength and bond of high-calcium fly ash geopolymer concrete were investigated. The high-calcium fly ash was from Mae Moh power plant in northern Thailand. ... The results indicated that fresh geopolymer concrete had short setting time of 28–58 min due to the presence of high calcium content of fly ash ...
Setting Time, Workability and Strength Properties of Alkali …
To examine the utilization of fly ash and GGBS as a cement substitute, it is necessary to study the standard consistency and setting time of geopolymer paste and workability as well as compressive strength of alkali activated fly ash and slag-based geopolymer concrete. The method used to determine these tests was the same as used for cement.
[PDF] Compressive Strength Prediction of Fly Ash-Based Concrete …
The compressive strength of concrete is a crucial parameter in structural design, yet its determination in a laboratory setting is both time-consuming and expensive. The prediction of compressive strength in fly ash-based concrete can be accelerated through the use of machine learning algorithms with artificial intelligence, which can effectively address the problems …
Setting Time and Workability of Geopolymerised Fly …
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 C191 and the flow table test per ASTM C1437, respectively.
How long does concrete take to set
Employ a mix design that includes supplementary cementitious materials like fly ash or slag, which can enhance early strength gain and reduce setting time. Hot Weather Concreting Practices: In hot weather, concrete naturally sets faster.
Sodium silicate effect on setting properties, strength behavior and
Representing an engineered mixture of coal fly ash, cement and water, cemented coal fly ash backfill (CCB) is typically employed for filling the openings created after coal excavation in the earth. ... 1 and 1.5 wt% in CCB that contains 25 wt% ordinary Portland cement OPC and 75 wt% coal fly ash. Backfill setting time was done by using the ...
Effects of the Loss on Ignition of Fly Ash on the Properties …
From Table 4, it is seen that the setting time was mainly affected by the cement content and the higher the substitution rate of fly ash, the longer the initial and final setting time. Taking the fly ash substitution ratio of 60% as an example, the initial setting time of fly ash concrete was 2.6 to 3.7 times of the control concrete.
Fly ash | PPT
7. The quality of fly ash is governed by IS 3812 - part I - 2003.The BIS specification limit for chemical requirement and physical requirement are given inTables 5.14 and 5.15 (IS 3812– 2003). High fineness, low carbon content, good reactivity are the essence of good fly ash. Since fly ash is produced by rapid cooling and solidification of molten ash, a large …
Setting Times of Fly Ash and Slag-Cement Concretes as …
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.
Rheology and Setting of High Volume Fly Ash Mixtures
Abstract While high volume fly ash (HVFA) concretes can be designed and produced to meet 28-d strength requirements and often even exceed the durability performance of conventional concretes, a persistent problem is the potentially long delay in setting time that produces concurrently long delays in finishing the concrete in the field.
Comparison between OPC and PPC (fly ash based cement) …
Gypsum stands for an additive and it's objective is to enhance the setting time of the cement to a executable 30 minutes or more. ... (Fly Ash Based) Cement: Alternatively, PPC (Portland ...
Class F Fly Ash Assessment for Use in Concrete Pavements
research recommended the selection of fly ash for low-slump concrete with reduced cementitious material content intended for paving applications. 17. Key Words Fly ash, low cement concrete, admixtures, superplasticizer, supplementary cementitious materials, compressive strength, durability 18. Distribution Statement No restriction.
The effects of hardening accelerator on microstructure and …
Concrete has grown exceedingly in demand as human society gets increasingly urbanized [1].Greenhouse gases emitted during the production of concrete account for 9 % of world greenhouse gas emissions, whereas the cement industry accounts for 79 % of overall concrete emissions [2].Today, worldwide cement output is over 4.1 billion tons per year, with …
LOW-CALCIUM FLY ASH-BASED GEOPOLYMER …
LOW-CALCIUM FLY ASH-BASED GEOPOLYMER CONCRETE: LONG-TERM PROPERTIES By S. E. Wallah and B. V. Rangan Research Report GC 2 Faculty of Engineering Curtin University of Technology Perth, Australia ... 3.7.3.2 Test Set up and Measurement 24 3.8. Drying Shrinkage Test 26 3.8.1. Test Specimens 26 3.8.2. Test parameters 27 3.8.3. Test Procedure 27
Setting time, sulfuric acid resistance, and strength …
Mortar and concrete setting time are related to the beginning of the polycondensation process, which takes longer time when fly ash is the only binder, or its content is high. ... Kumar [4] reported a 45-minute setting time when fly ash is partially replaced with 25% GBS, with only ... /Al 2 O 3 has an appreciable effect on setting time as long ...
Effect of Fly Ash on Setting Time
Our ready mixed concrete supplier recommends that we use a concrete with fly ash added to improve finishability. However, I've heard that fly ash retards the setting of concrete. Is it possible to add fly ash without affecting the concrete setting time?
Fly Ash and Bleeding
Q: Does fly ash affect concrete bleeding? A: A study by the Portland Cement Association compared the bleeding of concretes containing 10 different fly ashes with two control concretes containing no fly ash. In the study, Class C ashes reduced bleeding much more than Class F ashes. The ability to reduce bleeding, for most of the fly ashes, was related to a …
What Is Fly Ash and How Is It Used in Concrete?
In the commercial and industrial sectors, fly ash has a wide variety of applications and uses, though it is primarily known for improving the durability and workability of concrete mixes. Fly ash is also a filler in paints, adhesives, and metal and plastic composites. It's commonly used as structural fill for road construction and fly as…
Mechanical processing of wet stored fly ash for use as a …
Pre-screening and batch quantity had relatively minor effects on particle size reductions, with small differences also found between wet and dry stored fly ash. Extended …
Strength development of concrete with fly ash addition
cement Fig 5. Setting times vs fly ash content in the paste with C3 cement The setting times of cement paste with fly ash were determined using Vicat needle, according to PN-EN 196-3: 1996 [18]. As it is shown in Figs 3, 4, 5, the set-ting times are prolonged, a little in the case of C1 and C2 cement and significantly in case of C3 cement, with ...
Recycled gypsum powder from waste drywalls combined with fly ash …
Due to the longer set time required for fly ash noticed by the researcher during trial tests, all molds were removed after 5 days and cured in a moist closet. ... Calcium silicate hydrate (C–S–H) is the main reaction product in concrete, providing the majority of the long-term strength and durability (Mehta and Monteiro, 2014).