Compressive Strength of High Plastic Clay Stabilized with Fly Ash-Based Geopolymer and Its Synthesis Parameters

Author(s):  
Neeraj Varma ◽  
Tulasi Kumar ◽  
Vamsi Nagaraju
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
D. Kioupis ◽  
Ch. Kavakakis ◽  
S. Tsivilis ◽  
G. Kakali

This paper concerns the synthesis of foamed geopolymers using fly ash and metallic Si as the binder and the porogent agent, respectively. The Taguchi approach was applied in order to study the effect of some significant synthesis parameters such as the Si foaming agent content (% w/w fly ash based), the alkali type (R : Na or K), and the alkalinity (R/Al molar ratio) of the activation solution on the compressive strength and apparent density of the foamed geopolymers. The final products were characterized by means of XRD, FTIR, and SEM, while optical microscopy was applied for the evaluation of the porosity. Lightweight geopolymers with a compressive strength of 2.08–14.88 ΜPa and an apparent density of 0.84–1.55 g/cm3 were prepared by introducing a Si content up to 0.2% w/w on fly ash basis.


2018 ◽  
Vol 881 ◽  
pp. 158-164 ◽  
Author(s):  
Remigildus Cornelis ◽  
Henricus Priyosulistyo ◽  
Iman Satyarno ◽  
Rochmadi

Fly ash based geopolymer normally gets the optimum strength by heat curing. This is considered as a hindrance to in-situ applications. Therefore, development of fly ash based geopolymer that suitable for ambient curing will widen the application to the concrete structure. This paper reports the results of an experimental study on setting time and development of compressive strength of class C fly ash based geopolymer paste produced in ambient curing condition. The main synthesis parameters such as water to the geopolymer solid ratio, alkali to cementitious ratio and molarity of NaOH were varied to understand their individual effect on setting time and the mechanical properties of the resulting geopolymer. The results suggested that generally the setting time increased with the NaOH molarity and the compressive strength of 59 MPa was obtained for geopolymer mixture cured at ambient temperature for 28 days with alkali to a cementitious ratio of 0.35 and 10 M NaOH. The results will be useful for developing the knowledge of the use of high calcium fly ash in producing geopolymer. This would be beneficial to the understanding the future applications of this material as new binding material.


2013 ◽  
Vol 78 (6) ◽  
pp. 851-863 ◽  
Author(s):  
Irena Nikolic ◽  
Dijana Djurovic ◽  
Radomir Zejak ◽  
Ljiljana Karanovic ◽  
Milena Tadic ◽  
...  

The process of geopolymerization involves the reaction of solid aluminosilicate materials with highly alkaline silicate solution yielding an aluminosilicate inorganic polymer named geopolymer, which may be successfully applied in civil engineering as a replacement for cement. In this paper we have investigated the influence of synthesis parameters: solid to liquid ratio, NaOH concentration and the ratio of Na2SiO3/NaOH, on the mechanical properties and hydrolytic stability of fly ash based geopolymers in distilled water, sea water and simulated acid rain. The highest value of compressive strength was obtained using 10 mol dm-3 NaOH and at the Na2SiO3/NaOH ratio of 1.5. Moreover, the results have shown that mechanical properties of fly ash based geopolymers are in correlation with their hydrolytic stability. Factors that increase the compressive strength also increase the hydrolytic stability of fly ash based geopolymers. The best hydrolytic stability of fly ash based geopolymers was shown in sea water while the lowest stability was recorded in simulated acid rain.


In the current work, a problematic expansive high plastic clayey (CH) soil of Surat, Gujarat, India has been treated with commercial waste bagasse ash (BA) and ground granulated blast furnace slag (GGBS) for sustainable development. Swell shrink behavior, California bearing ratio, unconfined compressive strength for different curing period have been studied. As expansive soil is very sensitive to seasonal variation, cyclic drying and wetting study has been carried out on both treated and untreated samples. The optimum blend is observed to be in the proportion of 82.5%CH + 10%BA + 7.5%GGBS. The unconfined compressive test results indicate that strength of 28 days cured samples of optimum mix increases about three times and eight times when compared to untreated sample and uncured sample respectively. The soaked California bearing ratio (CBR) indicate the increase in strength with increasing curing periods from 7 to 28 days. Optimum mix shows the decrease in swelling pressure and an increase in shrinkage limit as compared to untreated soil. The experimental results show good improvement in swell-shrink behavior, unconfined compressive strength, and soaked California bearing ratio when combined with bagasse ash and slag. The findings of this study revealed that bagasse ash in combination with ground granulated blast furnace slag is suitable as a pozzolanic material in stabilization of high plastic clay to reach the target strength for structures with improved swell-shrink behavior.


2018 ◽  
Vol 17 (9) ◽  
pp. 2023-2030
Author(s):  
Arnon Chaipanich ◽  
Chalermphan Narattha ◽  
Watcharapong Wongkeo ◽  
Pailyn Thongsanitgarn

2018 ◽  
Vol 17 (8) ◽  
pp. 1855-1861
Author(s):  
Nicolae Taranu ◽  
Monther Abdelhadi ◽  
Ancuta Rotaru ◽  
Maria Gavrilescu

Author(s):  
A. Z. Mohd Ali ◽  
◽  
N. A. Jalaluddin ◽  
N. Zulkiflee ◽  
◽  
...  

The production of ordinary Portland cement (OPC) consumes considerable amount of natural resources, energy and at the same time contribute in high emission of CO2 to the atmosphere. A new material replacing cement as binder called geopolymer is alkali-activated concrete which are made from fly ash, sodium silicate and sodium hydroxide (NaOH). The alkaline solution mixed with fly ash producing alternative binder to OPC binder in concrete named geopolymer paste. In the process, NaOH was fully dissolved in water and cooled to room temperature. This study aims to eliminate this process by using NaOH in solid form together with fly ash before sodium silicate liquid and water poured into the mixture. The amount of NaOH solids were based on 10M concentration. The workability test is in accordance to ASTM C230. Fifty cubic mm of the geopolymer paste were prepared which consists of fly ash to alkaline solution ratio of 1: 0.5 and the curing regime of 80℃ for 24 hours with 100% humidity were implemented. From laboratory test, the workability of dry method geopolymer paste were decreased. The compressive strength of the dry mix of NaOH showed 55% and the workability has dropped to 58.4%, it showed strength reduction compared to the wet mix method.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2694 ◽  
Author(s):  
Shansuo Zheng ◽  
Lihua Niu ◽  
Pei Pei ◽  
Jinqi Dong

In order to evaluate the deterioration regularity for the mechanical properties of brick masonry due to acid rain corrosion, a series of mechanical property tests for mortars, bricks, shear prisms, and compressive prisms after acid rain corrosion were conducted. The apparent morphology and the compressive strength of the masonry materials (cement mortar, cement-lime mortar, cement-fly ash mortar, and brick), the shear behavior of the masonry, and the compression behavior of the masonry were analyzed. The resistance of acid rain corrosion for the cement-lime mortar prisms was the worst, and the incorporation of fly ash into the cement mortar did not improve the acid rain corrosion resistance. The effect of the acid rain corrosion damage on the mechanical properties for the brick was significant. With an increasing number of acid rain corrosion cycles, the compressive strength of the mortar prisms, and the shear and compressive strengths of the brick masonry first increased and then decreased. The peak stress first increased and then decreased whereas the peak strain gradually increased. The slope of the stress-strain curve for the compression prisms gradually decreased. Furthermore, a mathematical degradation model for the compressive strength of the masonry material (cement mortar, cement-lime mortar, cement-fly ash mortar, and brick), as well as the shear strength attenuation model and the compressive strength attenuation model of brick masonry after acid rain corrosion were proposed.


2013 ◽  
Vol 864-867 ◽  
pp. 1923-1928
Author(s):  
Yue Xu ◽  
Jian Xi Li ◽  
Li Li Kan

A new kind of high strength cementitious material is made from phosphogypsum (PG), active carbon and fly-ash. Through the orthogonal research, it was showed that the calcination temperature, retention time, dosage of active carbon and fly ash on the compressive strength of cementitious binder are the most important. The result also showed that, in the conditions of temperature 1200°C, time retention 30 min, dosage of active carbon 10%, dosage of fly ash 5%, the compressive strength of the cementitious material for 3d and 28d could reach to 46.35MPa and 92.70MPa, the content of sulfur trioxide was 11.60% accordingly. A lot of active mineral materials, such as dicalcium silicate, tricalcium silicate, tricalcium aluminate were formed in the calcination. The C-S-H gel, calcium hydroxide and ettringite were found in 3d and 28d hydrates. It is found that the lime saturation ratio and silica modulus need to be control between 0.40~0.65 and 4~8 in order to produce high strength cementitious material.


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