scholarly journals Retraction notice to “Comparative study on effects of Class F fly ash, nano silica and silica fume on properties of High Performance Self Compacting Concrete” [JCBM 94 (2015) 90-104]

2021 ◽  
Vol 304 ◽  
pp. 124708
Author(s):  
Mostafa Jalal ◽  
Alireza Pouladkhan ◽  
Omid Fasihi Harandi ◽  
Davoud Jafari
Keyword(s):  
Fly Ash ◽  
Comparative Study ◽  
Silica Fume ◽  
High Performance ◽  
Nano Silica ◽  
Self Compacting Concrete ◽  
Retraction Notice ◽  
Class F Fly Ash ◽  
Class F

scholarly journals Self Compacting Concrete – an Analysis of Properties using Fly Ash

2018 ◽  
Vol 7 (2.24) ◽  
pp. 135
Author(s):  
Dasarathy A K ◽  
M Tamil Selvi ◽  
D Leela ◽  
S Kumar
Keyword(s):  
Fly Ash ◽  
Low Cost ◽  
Cementitious Materials ◽  
The Self ◽  
Experimental Program ◽  
Reinforcing Bars ◽  
Self Compacting Concrete ◽  
Construction Market ◽  
Class F Fly Ash ◽  
Class F

Self  compacting concrete has ability involves not only high deformability of paste or mortar, but also resistance to segregation between coarse aggregate and  mortar  when the concrete flows  through the confined zone of reinforcing bars. Several researchers have employed the different methods to achieve self- compactability. In recent years, self-compacting concrete (SCC) has gained wide use for placement in congested reinforced  concrete structures with difficult casting conditions. For such applications, the fresh concrete must possess high fluidity and good cohesiveness. The initial results of an experimental program aimed at producing and evaluating SCC made with high volumes of fly ash are presented and discussed. Nine SCC mixtures and one control concrete were investigated in this study. The content of the cementitious materials was maintained constant (400 kg/m3), while the water / cementitious material ratios ranged from 0.35 to 0.45. The self-compacting mixtures had a cement replacement of 40,50 and 60% by Class F fly ash. Tests were carried out on all  mechanical properties of hardened concretes such as compressive strength were also determined. The self-compacting concretes developed a 28- day compressive strengths ranging from 26 to 48 MPa. The results show that an economical self-compacting concrete could be successfully developed by incorporating high-volumes of Class F fly ash. The present project investigates the making of self-compacting concrete more affordable for the construction market by replacing high volumes of Portland cement by fly ash. The study focuses on comparison of fresh properties of SCC containing varying amounts of fly ash with that containing commercially available admixture. Test result substantiate the feasibility to develop low cost SCC using Class F fly ash.  

scholarly journals Propiedades reológicas y mecánicas de un hormigón autocompactante con adición de nano-sílice y micro-sílice

2016 ◽  
Vol 6 (1) ◽  
pp. 1-14
Author(s):  
E. Sánchez ◽  
J. Bernal ◽  
A. Moragues ◽  
N. León
Keyword(s):  
Mechanical Properties ◽  
Silica Fume ◽  
Binary Mixtures ◽  
High Performance ◽  
Durable Resistance ◽  
Nano Materials ◽  
Nano Silica ◽  
Self Compacting Concrete ◽  
Palabras Clave ◽  
Micro Silica

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. 

An Investigation into Mechanical Properties of Self Compacting Concrete Incorporating Fly Ash and Silica Fume at Different Ages of Curing

2011 ◽  
Vol 261-263 ◽  
pp. 3-7 ◽  
Author(s):  
Ahmad Askari ◽  
Mohammad Reza Sohrabi ◽  
Yousef Rahmani
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Silica Fume ◽  
Fresh Concrete ◽  
Self Compacting Concrete ◽  
Flow Test ◽  
Different Ages ◽  
Self Compatibility ◽  
Normal Strength ◽  
Class F Fly Ash

In the present study, mechanical properties of self compacting concrete containing fly ash and silica fume as cement replacements are investigated at different ages of curing. Mechanical properties of specimens were examined at 7, 28 and 120 days for compressive strength and 28 days of curing for tensile strength. So as to reach self compatibility, different tests were carried out on fresh concrete such as slump flow test, T50, J-Ring, V-funnel and L-Box test. Self compacting mixtures had a cement replacement of 20, 30 and 40% with class F fly ash and 5, 10 and 15% with silica fume. The results show that normal strength self compacting concrete could be successfully produced using fly ash and silica fume.

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