The Mechanical Properties of Fly Ash Concrete Reinforced with Bamboo Fibers

This paper reports an investigation on mechanical properties of high volume fly ash (HVFA) concrete produced using different types of mixing water i.e. tap water and saturated lime water. The mechanical properties of ordinary Portland cement concrete are also investigated as control tests. The concrete were tested for their compressive strength, flexural strength and splitting tensile strength at the curing ages of 56 days. The results showed that strength development of high volume fly ash concrete up to 56 days is lower than ordinary portal cement. In addition, the flexural strength and splitting strength of concrete are lower than ordinary Portland cement. Moreover, the use of saturated lime water as mixing water reduces the mechanical properties of class C high volume fly ash concrete.

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Influence of Variable Temperature Curing on Mechanical Properties of Fly Ash Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.250-253.178 ◽

2011 ◽

Vol 250-253 ◽

pp. 178-181

Author(s):

Ya Ding Zhao ◽

Xue Ying Li ◽

Ling Chao Kong ◽

Wei Du

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Elastic Modulus ◽

Fly Ash ◽

Flexural Strength ◽

Variable Temperature ◽

Improve Performance ◽

Curing Conditions ◽

Fly Ash Concrete ◽

Better Than

Under variable temperature curing conditions(30 oC ~70 oC), concrete with fly ash whose compressive strength, flexural strength, and dynamic elastic modulus are better than ones without fly ash.Compared with constant temperature 20oC, 50 oC and 70 oC, variable temperature curing(VTC) is benefit for the improvement of mechanical properties of 30% fly ash concrete, but which is no advantage to improve performance of 50% fly ash concrete.

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Experiment and Micro-Mechanism Study on Mechanical Properties and Durability of High-Calcium Fly Ash Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.480-481.59 ◽

2011 ◽

Vol 480-481 ◽

pp. 59-65

Author(s):

Shuang Xi Li ◽

Tuan She Yang ◽

Zhi Ming Wang ◽

Quan Hu

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Frost Resistance ◽

Strength Development ◽

Hydration Reaction ◽

Optimal Dosage ◽

Fly Ash Concrete ◽

Low Calcium ◽

High Calcium ◽

High Calcium Fly Ash

Low-calcium fly ash is paid much attention for its wide use in engineering, the research and application technology of it are very mature, but as to high-calcium fly ash concrete, the researches on stability, mechanical property and durability of it are very less , The existing researches are still inadequate for practice of engineering. As to this problem, using small shek kip hydropower project as example, the volume stability of high-calcium fly ash concretes with different fly ash dosages are tested, then the optimal dosage of the high-calcium fly ash is determined; based on this, the impacts of high-calcium fly ash on the performance of mechanical properties , impermeability and frost resistance of concrete are studied; Finally, macro performance is analyzed from a micro-mechanism point of view through taking the electron micrograph. As the study shows, the optimal dosage of high-calcium fly ash should be taken as 20% -25%; for the concrete with special requirements, the dosage can be relaxed to 30% when the high-calcium fly ash achieves high quality. The compressive strength of high-calcium fly ash concrete is higher than the low-calcium fly ash concrete. Strength development advantage of high-calcium fly ash concrete reflects at the early age, this advantage takes the trend of weakening as the development of age. Concrete mixed with high-calcium fly ash has good performance in impermeability. The high-calcium fly ash has high activity, the high-calcium fly ash and secondary hydration reaction products can be filled into the pore capillary and cracks of the concrete structure, improving the pore structure, thereby increasing the density of cement paste. High-calcium fly ash concrete has good performance in frost resistance. The destructive effects of freeze-thaw cycles on cement structure has connection with the microstructure of cement and impermeability , the improvement of impermeability avoids the water entering into the concrete, reduces the risk of destruction caused by frost heave.The study on micro-mechanism proves well the macro-phenomena above.

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Impact of Silica Nanoparticles on the Durability of fly Ash Concrete

Frontiers in Built Environment ◽

10.3389/fbuil.2021.665549 ◽

2021 ◽

Vol 7 ◽

Author(s):

D. Ali ◽

U. Sharma ◽

R. Singh ◽

L. P. Singh

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Fly Ash ◽

Silica Nanoparticles ◽

Silica Fume ◽

Silica Nanoparticle ◽

Fly Ash Concrete ◽

Durability Properties ◽

Concrete Mix

In the present study, the mechanical and durability properties of silica nanoparticle (SNP)-incorporated fly ash (FA) concrete mix were examined after 365 days of exposure. The dosages of FA replaced by cement in the present study were 30%, 40%, and 50%, while 3% SNPs were added by the weight of cement in the FA incorporated mix. For a comparison of SNPs with silica fume (SF), 6% SF was added (by the weight of cement) and entire casting was performed at a constant water to binder (w/b) ratio of 0.29. The present work is the extension of a previous study wherein durability properties of the same mixes were reported for up to 180 days of exposure. Compressive strength results show that in the presence of SNPs, the enhancement in compressive strength was in the range of 10–14%, while, in presence of SF, 8–10% of the enhancement was observed as compared to control. However, exposed samples in a carbonation environment showed that the compressive strength of the control and SF incorporated mix increased, while SNP-incorporated samples showed negligible enhancement. Further, sulphate exposed mix show that compressive strength decreases, however, the SNP-incorporated mix showed the lowest reduction compared to other mixes. Therefore, the study shows that the SNP-incorporated mix has higher mechanical properties and more durability compared to other mixes in a severe environment.

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Effect of Nano-CaCO3 on the Mechanical Properties and Durability of Concrete Incorporating Fly Ash

Advances in Materials Science and Engineering ◽

10.1155/2020/7365862 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Yanqun Sun ◽

Peng Zhang ◽

Weina Guo ◽

Jiuwen Bao ◽

Chengping Qu

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Second Phase ◽

Fly Ash Concrete ◽

Concrete Mixtures ◽

Orthogonal Experiments ◽

Mix Proportion ◽

Electron Microscopy Analysis ◽

Binder Ratio ◽

Durability Of Concrete

Concrete mixtures consisting of nanomaterials and fly ash have been shown to be effective for improving the performance of concrete. This study investigates the combined effects of nano-CaCO3 and fly ash on the mechanical properties and durability of concrete; the mix proportion is optimized through orthogonal experiments. In the first phase, nine concrete mixtures were prepared with three water-to-binder ratios (0.4, 0.5, and 0.6), three fly ash contents (15%, 20%, and 25% replacement of the cement weight), and three nano-CaCO3 contents (1%, 2%, and 3% replacement of the cement weight). Based on the orthogonal analysis, the optimal concrete mix proportion was determined as a water-to-binder ratio of 0.4, 20% fly ash, and 1% nano-CaCO3. In the second phase, further investigations were carried out to examine the superiority of the optimal concrete and evaluate the synergistic effect of nano-CaCO3 and fly ash. The results showed that nano-CaCO3 contributed to increasing the compressive strength of fly ash concrete at the early ages, but its effect was quite limited at later ages. Furthermore, the scanning electron microscopy analysis revealed that the seeding effect, filling effect, and pozzolanic effect were the primary mechanisms for the improvement of concrete performance.

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