Investigation on chloride penetration in concrete mixes of different cement replacement percentages with fly ash and silica fume

2020 ◽  
Vol 33 ◽  
pp. 820-827 ◽  
Author(s):  
V.V. Sai Chand ◽  
B. Kameswara Rao ◽  
Ch. Hanumantha Rao
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Chloride Penetration ◽  
Cement Replacement

scholarly journals PROPERTIES OF CEMENT-FLY ASH MIXTURES WITH SUBSTANDARD FLY ASH AS A PARTIAL CEMENT AND FINE AGGREGATE REPLACEMENT

2021 ◽  
Vol 11 (3) ◽  
pp. 71-88
Author(s):  
Piseth Pok ◽  
Parnthep Julnipitawong ◽  
Somnuk Tangtermsirikul
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Sulfate ◽  
Chloride Penetration ◽  
The Other ◽  
Fine Aggregate ◽  
Carbonation Depth ◽  
Cement Replacement ◽  
Durability Properties ◽  
Compressive Strength Of Concrete

This research investigated the effects of using a substandard fly ash as a partial cement and/or fine aggregate replacement on the basic and durability properties of cement-fly mixtures. Experimental results showed that utilizing the substandard fly ash led to increase in water requirement and autoclave expansion of pastes. The strength activity indexes of the substandard fly ash passed the requirements of TIS 2135 and ASTM C618. Utilization of the substandard fly ash as cement replacement led to higher expansion of mortar bars stored in water and sodium sulfate expansion as compared to that of the OPC mixture. However, sodium sulfate resistance of mortar mixtures improved when utilizing the substandard fly ash as sand replacement material. The compressive strength of concrete at all ages was higher with the increase of the content of the substandard fly ash as sand replacement material. When the substandard fly ash was used as cement replacement material in concrete, the carbonation depth increased. On the other hand, the use of the substandard fly ash as sand replacement material decreased the carbonation depth of the concrete. Utilization of the substandard fly ash, both to replace cement and/or fine aggregate, reduced the rapid chloride penetration of the concrete.

Influence of Fly Ash as Cement Replacement on Chloride Penetration and Frost Resistance of Recycled Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 1031-1037
Author(s):  
Xiang Hao Wu ◽  
Pan Yuan ◽  
Yan Tao Jiao
Keyword(s):  
Fly Ash ◽  
Frost Resistance ◽  
Penetration Resistance ◽  
Ash Content ◽  
Chloride Penetration ◽  
Recycled Concrete ◽  
Diffusion Test ◽  
Cement Replacement ◽  
Water Test ◽  
Chloride Penetration Resistance

The influence of fly ash as cement replacement on pore structure, chloride penetration and frost resistance of recycled concrete is investigated by evaporable water test, chloride natural diffusion test, and freeze-thawing test. The experimental results indicate that adding fly ash to recycled concrete can decrease its porosity and improve its pore size distribution. Chloride penetration resistance of recycled concrete is enhanced firstly and then reduced with increasing of fly ash content. The best proportion replacing cement with fly ash is 20%. Fly ash content has a certain influence on the frost resistance of recycled concrete, and the frost resistance of recycled concrete only has been improved when the proportion of fly ash replacing cement achieves more than 20%.

Durability of Sustainable Self-Consolidating Concrete

2018 ◽  
Vol 765 ◽  
pp. 285-289
Author(s):  
Osama Ahmed Mohamed ◽  
Waddah Al Hawat ◽  
Omar Fawwaz Najm
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cementitious Materials ◽  
Chloride Penetration ◽  
Supplementary Cementitious Materials ◽  
Test Results ◽  
Self Consolidating Concrete ◽  
Human Footprint ◽  
Granulated Blast Furnace Slag

Supplementary cementitious materials such as fly ash, silica fume and ground granulated blast furnace slag (GGBS) have been used widely to partially replace cement in producing self-consolidating concrete (SCC). The production of cement is associated with emission of significant amounts of CO2 and increases the human footprint on the environment. Fly ash, silica fume, and GGBS are recycled industrial by-products that also impart favorable fresh and hardened properties on concrete. This study aims to assess the effect of the amounts of fly ash and silica fume on strength and chloride penetration resistance of concrete. Rapid Chloride Penetration Test (RCPT) was used to assess the ability of SCC to resist ingress of chlorides into concrete. SCC mixes with different dosages of fly ash and silica fume were developed and tested at different curing ages. Test results showed that replacing 20% of cement with fly ash produced the highest compressive strength of 67.96 MPa among all fly ash-cement binary mixes. Results also showed that replacing15% of cement with silica fume produced the highest compressive strength of 95.3 MPa among fly ash-cement binary mixes. Using fly ash and silica fume consistently increased the concrete resistance to chloride penetration at the early ages. Silica fume at all dosages results in low or very low levels of chloride penetration at all curing ages of concrete.

A laboratory study for full cement replacement by fly ash and silica fume

2012 ◽  
Vol 64 (12) ◽  
pp. 1135-1142 ◽  
Author(s):  
Monower Sadique ◽  
Hassan Al-Nageim ◽  
William Atherton ◽  
Linda Seton ◽  
Nicola Dempster
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Laboratory Study ◽  
Cement Replacement

Influence of Polypropylene Fiber and Silica Fume on the Chloride Penetration of High Performance Concrete with Fly Ash

2009 ◽  
Vol 405-406 ◽  
pp. 329-339
Author(s):  
Jing Liu ◽  
De Hua Deng ◽  
Ming Yin ◽  
Xu Li Hu
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Polypropylene Fiber ◽  
Chloride Penetration ◽  
Interfacial Zone ◽  
Fly Ash Concrete ◽  
Chloride Resistance ◽  
The Matrix

In this paper, the influence of polypropylene fibers (PPF) and silica fume (SF) on chloride penetration of high performance concrete (HPC) containing fly ash (FA) was examined. Three different HPC in which the amount of ordinary Portland cement is 360 kg/m3, via., A concrete with 120 kg/m3 of FA, B concrete with 0.9 kg/m3 of PPF and 120 kg/m3 of FA, C concrete with 0.9 kg/m3 of PPF and 96 kg/m3 of FA and 24 kg/m3 of SF were used for the study. Chloride resistance of concrete was evaluated. From the tests, it is found that the incorporation of PPF and no SF has less influence on the chloride resistance of the fly ash concrete at the age of 28 days. SEM examines B and C concretes specimens illustrating that just incorporating PPF induced more porous fiber-matrix interfacial zone (FMIZ) in B concrete which is detrimental to the chloride resistance, but the microstructures of both the matrix and FMIZ in C concrete with PPF and SF are denser. The plastic shrinkage cracking test proves that the cracking areas on the surface of B and C concrete with PPF are 12.2% and 20.7% of A concrete without PPF respectively.

Implementation of Artificial Neural Networks for Prediction of Chloride Penetration in Concrete

2018 ◽  
Vol 7 (2.28) ◽  
pp. 47
Author(s):  
Osama Ahmed Mohamed ◽  
Modafar Ati ◽  
Waddah Al Hawat
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Fly Ash ◽  
Silica Fume ◽  
Chloride Penetration ◽  
Critical Parameters ◽  
Experimental Program ◽  
Fine Aggregate ◽  
Ann Models ◽  
Artificial Neural

Artificial Neural Networks (ANN) has received a great attention from researchers in previous decade to predict different aspect of engineering problems. The aim of this research is to present an implementation of ANN to predict the Chloride penetration of self-consolidating concrete (SCC), containing various amounts of cement replacement minerals including fly ash, silica fume, and slag.  The ability of concrete to resist chloride penetration is measured using Rapid Chloride Penetration (RCP) test through an experimental program. One- and two-layer ANN models were developed by controlling the critical parameters affecting chloride penetration to predict the results of RCP test.  The ANN models were developed using various parameters including ratio of water-to-binder (w/b), course aggregate, fine aggregate, fly ash, and silica fume. It was shown that the prediction accuracy of ANN models was sensitive to combinations of learning rate and momentum. Data used to train and test the ANN were obtained through an experimental program conducted by the authors.  

Effect of Copper Slag as a Fine Aggregate on the Durability Characteristics of High-Performance Concrete (HPC) Containing Silica Fume

2020 ◽  
Vol 07 (02) ◽  
pp. 1-10
Author(s):  
Rizwan Ahmad Khan ◽  
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Copper Slag ◽  
Chloride Penetration ◽  
Interfacial Transition Zone ◽  
Fine Aggregate ◽  
Fresh Properties ◽  
Fine Aggregates ◽  
Effect Of Copper

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.

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