scholarly journals Strength Charecterstics of Concrete with Partial Replacement of Cement by Fly Ash and Activated Fly Ash

2019 ◽  
Vol 8 (4) ◽  
pp. 4299-4305 ◽  

This paper reveals mainly about the prime effects of using fly ash, and activated fly ash which is considered to replace cement in concrete, on the concrete strength. For this reason, proper experiments has been done in the lab to investigate the behavior of fly ash and activated fly ash ratio on the strength and workability parameters of concrete. The compressive strength of concrete specimens with replacement ratios of 30% and 40% 50%, and aged 7 and 28 days are measured for M30 as per IS 10262 2009 grade of concrete and are compared with those of the concrete specimens without fly ash. The results shown that strength of partially replaced cement by activated fly ash in concrete enhanced strength is observed and it is slow but strong and continuous process when compared to the concrete without fly ash. And optimum replacement of fly ash ratio can be found out at the maximum compressive tensile and flexural strength of concrete. The main aim of this paper is to study the strength properties of concrete with fly ash and activated fly ash. And compare the results and opt for the best replacement to eliminate more use of cement in concrete.

2012 ◽  
Vol 204-208 ◽  
pp. 3970-3973
Author(s):  
Reagan J. Case ◽  
Kai Duan ◽  
Thuraichamy G. Suntharavadivel

As a part of a large research program aiming at the cementitious materials containing recycled materials at Central Queensland University – Australia, the current paper presents the preliminary results of a study on the effects of fly ash, which is used to replace cement in concrete, on the concrete compressive strength. For this purpose, systematic experiments have been carried out to investigate the influences of fly ash ratio and age. The compressive strength of concrete specimens with replacement ratios of 15%, 30% and 45%, and aged 7 and 28 days are measured and are compared with those of the concrete specimens without fly ash at the same ages. The results demonstrate that the strength of fly ash containing concrete improves more slowly but more strongly with aging, than their fly ash free counterparts, and an optimum fly ash replacement ratio exists where the maximum compressive strength of fly ash containing concrete can be achieved, and the maximum strength for the specimens aged 28 days and above is higher that of fly ash free concrete. Furthermore, the observation strength behaviours are analysed and discussed in terms of the influences of fly ash on interface reactions and interface bonding strength.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Eluozo S.N. ◽  
Dimkpa K

Wood and fly ash were observed to have significant qualities that could improved the strength of self compacting concrete, the material were applied to increase the compressive strength of concrete strength, this material could be the demanding material for partial  replacement for cement, the study observed the behaviour of the material from experts that applied these material through experimental investigation, but the study monitored the behaviour of this material by applied modeling and simulation to determine other effect that could influence the behaviour of this materials in compressive strength, this was to determine the  significant effect on the addictive applied as partial replacement for cement, lots of experts has done works on fly ash through experiment concept, but the application of predictive concept has not be carried out, the  adoption of this concept has expressed other parameters that contributed to the efficiency of  wood and fly ash as partial replacement for cement on self compacting concrete. The study adopting modeling and simulation observed 10 and 20% by weight of cement as it is reflected on its performance in the simulation, from the simulation wood recorded 10% as it was observed from the growth rate of this self compacting concrete reflected from the trend, the simulation for model validation were compared with the works of the studies carried out [20]. And both values developed best fits correlation


2019 ◽  
Vol 5 (4) ◽  
pp. 913-921 ◽  
Author(s):  
Azmat Ali Phul ◽  
Muhammad Jaffar Memon ◽  
Syed Naveed Raza Shah ◽  
Abdul Razzaque Sandhu

This paper investigates the compressive strength properties of concrete with Ground Granulated Blast Furnace Slag (GGBS) and Fly Ash in concrete by partial replacement of cement. The incremental demand of cement in the construction field is a concern for environmental degradation, in this regard; replacement of cement is carried out with waste materials by using GGBS and Fly Ash. On optimum level of GGBS and Fly Ash was assessed with varied percentage from 0 to 30% for different curing days. Replaced concrete were tested with the slump, compaction factor, Vee-bee and compressive strength. Cement to water ratio was maintained at 0.47 for all mixes. The compressive strength tests were conducted for 3, 7, 14 and 28 days of curing on a M25 grade concrete. The results obtained from the slump, compaction factor, Vee-bee and compressive strength of concrete containing GGBS and Fly Ash was increased as the curing time increases. The workability of replaced concrete improved when slump value achieved 30% as compared to controlled one SF0 and the compressive strength obtained 26.30% improvement at SF9 as compared to SF0. The outcomes indicated that the addition of GGBS and Fly Ash enhances the workability and compressive strength which eventually improved the mechanical properties of concrete.


2020 ◽  
Vol 6 (7) ◽  
pp. 1400-1410
Author(s):  
Joel Sam

Decreasing our over-reliance on cement as an ingredient in the making of concrete due to its contribution to the CO2 emissions has led to numerous researches been conducted to find suitable replacement for cement in concrete mixes.  Materials like fly ash, ground granulated blast furnace slag, silica fume, rice husk ash and metakaolin among others have been identified as materials that can at the very least be used as a replacement for cement in concrete mix. These materials are referred to as supplementary cementitious materials (SCMs). This paper reviewed the work that has been done on the use of fly ash and rice husk ash as partial replacements for concrete, its chemical composition and its effect on the compressive strength of concrete. Charts, tables and figures were employed as tools to study the various chemical compounds of fly ash and rice husk ash. It was seen that depending on how the coal or rice husk was initially processed the percentage of some of the minor compounds like Sodium oxide (Na2O), Titanium oxide (TiO2) and Phosphorus pentoxide (P2O5) were sometimes very low or not recorded as part of the final product.  The data on the compressive strength of concrete after fly ash and rice husk ash had been added in percentage increments of 0%, 10%, 20%, 30%, 40%, 50% and 0%, 5%, 7.5%, 10%, 12.5%, 15% respectively analysed over a minimum period of 7 days and a maximum period of 28 days found out that the optimal percentage partial replacement of fly ash and rice husk ash for a strong compressive concrete strength is 30% of fly ash and 7.5% of rice husk ash.


Author(s):  
Mantu Kumar

Abstract: Among all the current construction materials, concrete occupies a unique position. Concrete is the most often utilised building material. Cement production emits CO2, which is harmful to the environment. One of the most crucial ingredients in concrete production is cement. Experiments were carried out to see how different percentages of Fly Ash and GGBS affected the mechanical qualities of M60 grade concrete. After 7, 14, and 28 days of curing, the compressive strength of concrete cubes with suggested replacement was determined. Compressive strength, split tensile strength, and flexural strength are all evaluated on the cubes, cylinders, and prisms. The primary goal of this study is to compare the fresh and hardened characteristics of M-60 grade control concrete with concrete prepared with varied ratios of fly ash and GGBS Keywords: GGBS, Fly Ash, Durability, Compressive Strength, Tensile Strength, Flexural Strength, Slum cone Test


2016 ◽  
Vol 866 ◽  
pp. 3-8 ◽  
Author(s):  
Osama Ahmed Mohamed ◽  
Waddah Al Hawat

Fly ash is a sustainable partial replacement of Portland cement that offers significant advantages in terms of fresh and hardened properties of concrete. This paper presents the findings of a study that aims at assessing the durability and strength properties of sustainable self-consolidating concrete (SCC) mixes in which Portland cement was partially replaced with 10%, 20%, 30%, and 40% fly ash. The study confirms that replacing Portland cement with fly ash at all of the percentages studied improves resistance of concrete to chloride penetration. The 40% fly ash mix exhibited the highest resistance to chloride penetration compared to the control mix. Despite the relative drop in compressive strength after 7 days of curing, the 28-day compressive strength of 40% SCC mix reached 55.75 MP, which is very close to the control mix. The study also confirms that adding 1%, 1.5%, and 2% basalt fibers, respectively, to the 40% fly ash mix improves the resistance to chloride penetration compared to the mix without basalt fibers.


2020 ◽  
Vol 13 (3) ◽  
pp. 315-321
Author(s):  
Dhiraj Ahiwale ◽  
Rushikesh Khartode

Now days, the waste rice husk from rice mill, marble powder from tile industry and fly ash from steam power plant are necessary to utilize as partial replacement of cement for concrete production. Large scale production of cement required consumption of raw materials and energy as well as emissions to air which posse’s environmental threat in various areas of country. Apart from the environmental threat, there still exists the problem of shortage in many areas. Therefore, substitute material for concrete needs to be considered. The paper aims to analyze the compressive strength of concrete cubes and flexural strength of concrete beams made from partially replaced cement, sand, and coarse aggregate. This research study adopted in laboratory on 48 total specimens of grade M25 concrete cubes of size 150x150x150mm and concrte beams of size 100x100x500mm were casted. Out of the 48 concrete specimens cast, 6 each were made out 10%, 20%, and 30 % replacement of fly ash, rice husk ash and marble powder to cement in concrete. It was found that the compressive strength and flexural strength of concrete made from the mixture of 20 % partially replaced cement, sand and coarse aggregate was similar than the concrete made from without replaced cement , sand and coarse aggregate.


In this study, full and partial replacement of stone aggregate by ceramic insulator scrap and partial replacement of cement by fly ash has been done in order to enhance economy in construction. More once, the solution of disposal of wasting from ceramic insulator manufacturing company and thermal power plant is also achieved. Further various mechanical properties of ceramic insulator scrap such as crushing value, impact value, abrasion value, specific gravity, sieve analysis and water absorption has been studied and obtained to make the study fruitful. Concrete of grade M15 is used to study the compressive strength properties of stone and ceramic aggregates. Replacement of stone aggregates by ceramic aggregates has been done in stages starting from 0% to 100% each stage possessing the variation of 10% and in all the specimens 30% of cement is replaced by 35% of fly ash. Six number of cube samples are cast for each variation and the compressive strength of the same have been obtained at 7, 28 and 56 days of age. Totally 216 cubes are cast and tested for compression. It is found that the optimum percentage at which the stone aggregate can be replaced by ceramic aggregates is 50% and 30% of cement can be replaced by 35% fly ash.


2011 ◽  
Vol 250-253 ◽  
pp. 33-39
Author(s):  
Xiao Lu Yuan ◽  
Bei Xing Li ◽  
Shang Chuan Zhao ◽  
Shi Hua Zhou

This paper investigates mechanical characteristics of concrete exposed to external flexural load, de-icing salt and freeze-thaw cycles. Concrete specimens made with ordinary Portland cement or ordinary Portland cement incorporating fly ash with the replacement of 10% or 20%, or 0.7/10000 air-entraining agent and 20% fly ash, or ground blast furnace slag with the replacement of 15% or 30%, were made and exposed to flexural load, freeze-thaw and de-icing salt environment. Mechanical properties of concrete including compressive strength and flexural strength were measured. Phase composition of samples was determined by means of x-ray diffraction (XRD). Results indicate that increasing flexural stress ratios reduced compressive strength and flexural strength of concrete, and presented higher improvement of mineral admixtures in concrete strength. Incorporation of mineral admixtures and air-entraining agent decreased the loss of concrete strength. X-ray diffraction analysis showed the presence of abundant calcium chloroaluminate and ettringite in paste samples.


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