Study of replacement of Silica Fume & Taftan Pozzolan to Large hardened concrete properties

Document Type : p

Authors

1 Faculty of Engineering -Department of Civil Engineering,ISLAMIC AZAD UNIVERSITY,Neyshabur Branch

2 Geotechnical Master's Degree, Semnan University

3 Institute for Energy & Hydro Technology, Civil Department, Mashhad

Abstract

Thermal cracks in concrete caused by temperature gradients at an early age are among the most destructive issues in massive concrete structures such as concrete dams, bridge pillars and large foundations of structures. Nowadays, using cement supplements is a common solution to effectively control thermal issues in such structures. The present study is intended to investigate the effect of using micro silica and pozzolan of taftan (khash) instead of a certain percentage of cement on thermal behavior and hydration of massive concretes. For this purpose, 11 concrete mix designs were investigated as 2 and 3 component mixtures of silica and pozzolan khash with a w/c ratio of 0.5 and cement grade 450 kg / m3. The results indicate that replacement of silica and pozzolan with a certain percentage of cement can significantly reduce the maximum temperature of the mixing. Moreover, the substitution of Khash Pozzolan and micro-silica respectively leads to an increase and decrease of concrete's compressive strength at its early ages. Finally, the mix design in which 25% of Pozzolan with 20% micro silica is used instead of cement, increased the compressive strength by 25% and reduced the maximum temperature by 7 ° C, which was introduced as picked three-component mix design.

Keywords

References

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Concrete Research
Volume 13, Issue 4 - Serial Number 32
January 2021
Pages 123-136

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