Mechanical and durability characteristics of high performance self-compacting concrete containing flyash, silica fume and graphene oxide

2021 ◽  
Vol 43 ◽  
pp. 2361-2367
Author(s):  
Damma Manikanta ◽  
Durga Prasad Ravella ◽  
Sri Rama Chand M. ◽  
Janardhan Yadav M.
2016 ◽  
Vol 6 (1) ◽  
pp. 1-14
Author(s):  
E. Sánchez ◽  
J. Bernal ◽  
A. Moragues ◽  
N. León

Propiedades reológicas y mecánicas de un hormigón autocompactante con adición de nano-sílice y micro-síliceRESUMENEl hormigón autocompactante es el resultado de diseñar mezclas de calidad con capacidad para asegurar su correcta colocación en estructuras fuertemente armadas en las cuales el proceso del vibrado resulta muy complicado y con riesgo de alterar la posición de las armaduras. Unido a las ventajas de este hormigón y debido a la mayor demanda de hormigones de altas prestaciones, se utiliza humo de sílice y, más recientemente, nanomateriales como adiciones. Principalmente nano-sílice. El objetivo de este trabajo es obtener hormigones autocompactantes con nano-sílice, humo de sílice y mezclas binarias de ambas adiciones que satisfagan la demanda de altas resistencias mecánicas y durables, determinando que la dosificación con mejores prestaciones es la que contiene 2.5% de nano y 2.5%.de humo de sílice. Palabras clave: Autocompactante; nanosílice; humo de sílice; reología; propiedades mecánicas. Rheological and mechanical properties of self-compacting concrete with the addition of nano-silica and microsilicaABSTRACTSelf-compacting concrete is the result of designing a quality concrete with the capacity to ensure placement of reinforcement in heavily reinforced structures in which the process of vibrating is very complicated and risky by altering the position of the reinforcement. Together with the advantages of this concrete and due to the increased demand for high-performance concretes, the silica fume, and more recently, the nano-materials are used as additions, but mainly the nano-silica. The objective of this work is to obtain self compacting concrete with nano-silica, silica fume and binary mixtures of the two additions to meet the demand for high mechanical and durable resistance. The mix with better performance is that with 2.5% of nano-sílica and 2.5% silica fume. Keywords: self-compacting concrete; nanosilica; silica fume; rheology; mechanical properties. Propriedades reológicas e mecânicas de um concreto auto adensável, com a adição de nano sílica e de micro sílica (sílica ativa)RESUMOO Concreto Auto-adensável é o resultado da concepção de um concreto de qualidade com a capacidade para assegurar a colocação de reforço em estruturas fortemente armados em que o processo de vibração é muito complicado e arriscado por alterar a posição da armadura . Juntamente com as vantagens deste concreto e devido ao aumento da procura de concretos de alto desempenho , o fumo de sílica e mais recentemente , os nano-materiais são usados como adições . Principalmente a nano- sílica. O objetivo deste trabalho é a obtenção de concreto auto- adensável com nano- sílica , sílica ativa e misturas binárias das duas adições para atender a demanda de alta resistência mecânica e durável. A mistura com melhores desempenhos é aquela que contém 2,5 % de nano - sílica e 2,5% de pó de sílica . Palavras-chave: Auto-compactável; nano-sílica; sílica activa; reologia; propriedades mecánicas. 


BUILDER ◽  
2019 ◽  
Vol 258 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Milena Kucharska

The paper analyses the impact of casting direction of self-compacting concrete (SCC) on its bond quality to steel reinforcing bars. Tests were performed on high performance self-compacting concretes with different amount of silica fume to cement mass. Experiment was carried out on 480 mm height specimens, which allowed determining changes of bond condition along its height. The ribbed reinforcing bars have been placed perpendicularly to the direction of casting. Casting was performed from two points – from the bottom and the top of the form. Research has shown that casting from the bottom of the form improves bond strength and quality.


Author(s):  
Rizwan Ahmad Khan ◽  

This paper investigates the fresh and durability properties of the high-performance concrete by replacing cement with 15% Silica fume and simultaneously replacing fine aggregates with 25%, 50%, 75% and 100% copper slag at w/b ratio of 0.23. Five mixes were analysed and compared with the standard concrete mix. Fresh properties show an increase in the slump with the increase in the quantity of copper slag to the mix. Sorptivity, chloride penetration, UPV and carbonation results were very encouraging at 50% copper slag replacement levels. Microstructure analysis of these mixes shows the emergence of C-S-H gel for nearly all mixes indicating densification of the interfacial transition zone of the concrete.


2019 ◽  
Vol 164 (0) ◽  
pp. 193-213
Author(s):  
Taha E. Taha ◽  
Ahmed M. Tahwia ◽  
Ahmed H. Abdelraheem

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