Thermally and mechanically treated Greek palygorskite clay as a pozzolanic material

2021 ◽  
Vol 215 ◽  
pp. 106306
Author(s):  
George Georgopoulos ◽  
Efstratios Badogiannis ◽  
Sotirios Tsivilis ◽  
Maria Perraki
2015 ◽  
Vol 804 ◽  
pp. 129-132
Author(s):  
Sumrerng Rukzon ◽  
Prinya Chindaprasirt

This research studies the potential for using waste ash from industrial and agricultural by-products as a pozzolanic material. Classified fly ash (FA) and ground rice husk ash (RA) were the materials used. Water requirement, compressive strength and porosity of cement mortar were investigated. Test results indicated that FA and RA (waste ash) have a high potential to be used as a good pozzolanic material. The water requirement of mortar mix decreases with the increases in fly ash content. For ground rice husk ash (RA), the water requirement of mortar mix increases with the increases in rice husk ash content. In addition, the reduction in porosity was associated with the increase in compressive strength.


2015 ◽  
Vol 668 ◽  
pp. 419-432 ◽  
Author(s):  
Aline Figueirêdo Nóbrega de Azerêdo ◽  
Givanildo Azeredo ◽  
Arnaldo Manoel Pereira Carneiro

Many works have shown that metakaolin is very good pozzolanic material for using in lime mortars and Portland cement mortars. Alternatively, many studies also have shown that kaolin wastes, after some treatment, can become a high quality pozzolans. Most of these studies have discussed about the microstructural characteristics and hardened properties of pastes, mortars or concretes mixes containing metakaolin or kaolin wastes cured in moist environment. In this work pastes and mortars made of metakaolin and hydrated lime (L-MK), which the metakaolin was obtained from the kaolin production waste, were assessed in their hardened state. Two curing conditions were considered: dry and moist environment; and three ages of curing (28, 90 and 180 days) were studied. Pastes were assessed by XRD and TG/DTG. In pastes according to the XRD and TG/DTG results, the main hydrated products found were strätlingite, in moist curing, and monocarboaluminate, in dry curing. Properties like flexural and compressive strengths, water absorbed capillarity and loss mass variation were studied in mortars. The results showed that mortars in dry curing presented lower strengths than one in moist curing. In moist curing mortars presented compressive strength values around 12 MPa and in dry curing this value reached 6 MPa. This fact indicate that the strätlingite maybe is responsible for the high strengths in mortars in moist curing when compares with the strengths of mortars cured in dry environment. Further the results showed that mortars in dry curing presented higher water absorbed and mass loss variation than mortars in moist curing.


Sedimentology ◽  
2019 ◽  
Vol 66 (5) ◽  
pp. 1803-1824 ◽  
Author(s):  
Brooks H. Ryan ◽  
Stephen E. Kaczmarek ◽  
John M. Rivers
Keyword(s):  

Author(s):  
Savita Chaudhary ◽  
Aditya Pratap Singh

The optimized RHA, by controlled burn or grinding, has been used as a pozzolanic material in cement and concrete. Using it provides several advantages, such as improved strength and durability properties, and environmental benefits related to the disposal of waste materials and to reduced carbon dioxide emissions. Up to now, little research has been done to investigate the use of RHA as supplementary material in cement and concrete production .The main objective of this work is to study the suitability of the rice husk ash as a pozzolanic material for cement replacement in concrete. However it is expected that the use of rice husk ash in concrete improve the strength properties of concrete. Also it is an attempt made to develop the concrete using rice husk ash as a source material for partial replacement of cement, which satisfies the


2019 ◽  
Vol 19 (1) ◽  
pp. 21-30
Author(s):  
Arifudin Nur ◽  
Suryo Hapsoro Tri Utomo ◽  
M. Zudhy Irawan

Abstract Expansive soils have high swelling and shrinkage potentials, which may cause damage to road structures. Therefore, stabilization is required. One method of stabilization is to use lime and spent catalysts with the aim of increasing carrying capacity and reducing swelling. Spent catalyst is a petroleum processing waste and classified as pozzolanic material. The addition of lime and spent catalysts can increase the CBR value and reduce swelling of soils. The results of this study indicate that the maximum increase in soaked CBR and unsoaked CBR values occurred in soil mixtures with optimum lime content and 12% spent catalyst with 7 days of curing. While the soil mixture with optimum lime content and 12% spent catalyst, with 7 days of curing, is the best mixture that produces soaked CBR value of 49.67%, swelling of 0.15%, and plasticity index value of 11.97%, so the soil meets the requirements to be used as pavement subgrade. Keywords: expansive soil, stabilization, road structure, subgrade, road pavement  Abstrak Tanah ekspansif memiliki potensi pengembangan dan penyusutan yang tinggi, sehingga dapat menyebabkan kerusakan struktur jalan. Oleh sebab itu, perlu dilakukan stabilisasi. Salah satu metode stabilisasi adalah menggunakan kapur dan spent catalyst dengan tujuan meningkatkan kapasitas dukung dan menurunkan swelling. Spent catalyst merupakan limbah pengolahan minyak bumi dan termasuk bahan pozzolan. Penam-bahan kapur dan spent catalyst mampu meningkatkan nilai CBR dan mereduksi swelling. Hasil studi ini menunjukkan bahwa peningkatan maksimum nilai CBR soaked maupun CBR unsoaked terjadi pada campuran tanah dengan kadar kapur optimum dan 12% spent catalyst dengan peraman 7 hari. Sedangkan campuran tanah dengan kadar kapur optimum dan 12% spent catalyst, dengan peraman 7 hari, merupakan campuran terbaik yang menghasilkan nilai CBR soaked sebesar 49,67%, swelling sebesar 0,15%, dan nilai indeks plastisitas sebesar 11,97%, sehingga tanah memenuhi syarat untuk digunakan sebagai tanah dasar perkerasan jalan. Kata-kata kunci: tanah ekspansif, stabilisasi, struktur jalan, tanah dasar, perkerasan jalan


2020 ◽  
Vol 11 (1) ◽  
pp. 58-65
Author(s):  
G. Lizia Thankam ◽  
Neelakantan Thurvas Renganathan

AbstractThough being an ancient trend, usage of the homogeneous material cement in the construction industry is steadily getting eradicated with the springing up of supplementary cementing materials (SCM). Metakaolin is an imminent mineral admixture extracted from the mineral ore kaolinite, which enhances the interfacial zone by more efficient packing at the cement paste-aggregate particle interface, thus reducing the bleeding and producing a denser, more homogeneous transition zone microstructure. This paper depicts the various repercussions of the pozzolanic material metakaolin in the fresh and hardened properties of concrete when replaced with cement in finite amount. Also, it states the behavior of high-performance concrete and self-compacting concrete with metakaolin.


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