Volcanic Ash Content of the Soil of a Festuca Viridual “Bald” on a Mountain in Northern Idaho

This paper describes the result of investigating volcanic ash of Mount Kelud as fly ash substitute material to produce geopolymer concrete. The test was held on geopolymer concrete blended with 0%, 25%, 50% and 100% fly ash replacement with volcanic ash. Natrium Hidroxide (NaOH) with concentration of 12 molar and Natrium Silicate (Na2SiO3) were used as alkaline activator. While alkali-activator ratio of 2 was used in this research. The physical properties was tested by porosity and setting time test, while split tensile strength presented to measure brittle caracteristic of geopolymer concrete. The result shown that increasing volcanic ash content in the mixture will increase setting time of geopolymer paste. On the other hand increasing volcanic ash content will reduce split tensile strength and porosity of geopolymer concrete. After all replacing fly ash with volcanic ash was suitable from 25% to 50% due to its optimum physical and mechanical properties.

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Susceptibility of volcanic ash-influenced soil in northern Idaho to mechanical compaction /

10.5962/bhl.title.81812 ◽

1993 ◽

Cited By ~ 3

Author(s):

Deborah S. Page-Dumroese ◽

◽

Keyword(s):

Volcanic Ash ◽

Mechanical Compaction ◽

Northern Idaho

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Susceptibility of volcanic ash-influenced soil in northern Idaho to mechanical compaction

10.2737/int-rn-409 ◽

1993 ◽

Cited By ~ 3

Author(s):

Deborah S. Page-Dumroese

Keyword(s):

Volcanic Ash ◽

Mechanical Compaction ◽

Northern Idaho

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ROLE OF GRANULOMETRY OF MIXED BINDERS IN FORMATION OF THEIR MICROSTRUCTURE AND STRENGTH

Bulletin of Belgorod State Technological University named after V G Shukhov ◽

10.34031/2071-7318-2021-6-7-33-43 ◽

2021 ◽

Vol 6 (7) ◽

pp. 33-43

Author(s):

L. Zagorodnyuk ◽

D.S. Mahortov ◽

V. Ryzhikh ◽

D. Sumskoy ◽

M. Dayronas

Keyword(s):

Portland Cement ◽

Volcanic Ash ◽

Pore Space ◽

Ash Content ◽

Cement Stone ◽

Hydration Products ◽

Mechanical Mixing ◽

Mineral Fillers ◽

Active Interaction

A complex system is formed when grinding Portland cement and various mineral fillers. It consists of grains of various sizes with a predominance of a highly dispersed phase. The work investigates the effect of mixed binders prepared on the basis of Portland cement and volcanic ash at various dosages. The analysis of volcanic ash particles is carried out. It is found that the presence of the smallest fractions in the range from 0.3 to 0.07 microns predicts active interaction in the system and the filling of the pore space with hydration products. It has been established that mixed binders obtained by mechanical mixing (without grinding) with a content of 10% volcanic ash have a strength 13% higher than no addition cement. Mixed binders activated by milling in a vibration mill with a volcanic ash content of 10% are characterized by an increase in compressive strength by 22%, which saves Portland cement by up to 10%. Mixed binders with a volcanic ash content of 20% correspond to the strength of cement free. The results obtained indicate the effectiveness and feasibility of using volcanic ash as a mineral component of mixed binders. The microstructure of a cement stone sample from an activated mixed binder is highly homogeneous, dense intergrown plates of a secondary hydrosilicate structure are clearly visible in the sample cleavage, and crystalline products of pozzolanic reactions between ash particles and cement hydration products are formed on the surfaces of secondary hydrosilicate structures. The purpose of this article is to study the role of granulometry of mixed binders in the formation of their microstructure and strength.

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