Frost-Resisting Property of Bridge Concrete in Alpine Frigid Region

2013 ◽  
Vol 857 ◽  
pp. 239-247
Author(s):  
Yin Chuan Guo ◽  
Ai Qin Shen ◽  
Jian Wang ◽  
Hong Ji Zhao
Keyword(s):  
Fly Ash ◽  
Water Consumption ◽  
Reference Value ◽  
Ash Content ◽  
Impact Mechanism ◽  
Air Content ◽  
Influence Of Water ◽  
Binder Ratio ◽  
The Impact ◽  
Water Binder Ratio

Supported by the Guozigou-bridge, the paper studied the Frost-resisting property of bridge concrete in alpine frigid region. Researched the effect of water-binder ratio, fly-ash content, water consumption and air-entraining agent consumption, and reveals the impact mechanism of frost-resisting property of bridge concrete in alpine frigid region. Analyzed the influence rule of frost-resisting property and showed reference value of concrete's ingredient rate in alpine frigid region. The result showed that low water-binder ratio and water consumption can effectively improve the deicer-frost resistance of concrete and the influence of water consumption is more significant. Best air content between 4.5% ~ 4.5%.

scholarly journals Experimental Study on Durability Improvement of Fly Ash Concrete with Durability Improving Admixture

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Hong-zhu Quan ◽  
Hideo Kasami
Keyword(s):  
Fly Ash ◽  
Experimental Studies ◽  
Drying Shrinkage ◽  
Replacement Ratio ◽  
Fly Ash Concrete ◽  
Air Content ◽  
Carbonation Resistance ◽  
Binder Ratio ◽  
Water Binder Ratio

In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%–20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized.

Influence of the Fly-Ash Content of Concrete at Low Water-Binder Ratio on Hydration Degree of Binders and Cement

2011 ◽  
Vol 250-253 ◽  
pp. 445-449
Author(s):  
Li Wei Xu ◽  
Jian Lan Zheng
Keyword(s):  
Fly Ash ◽  
Temperature Rise ◽  
High Performance Concrete ◽  
Ash Content ◽  
Adiabatic Temperature ◽  
Mineral Admixture ◽  
Hydration Degree ◽  
Adiabatic Temperature Rise ◽  
Binder Ratio ◽  
Water Binder Ratio

The hydration degree of binders and cement is investigated by measuring the adiabatic- temperature rise of concrete at low water-binder ratio with different fly-ash content. The results denote that, with a constant water-binder ratio, both of the hydration degree of binders and that of cement decrease with the increasing fly-ash content in the early stage. In a later stage, however, the hydration degree of cement increases with the increasing fly-ash content and the hydration degree of binders peaks when the fly-ash content is 35%. Fly ash is one of the mineral admixture of which high-performance concrete is made up. It brings down the rise of concrete temperature significantly and helps solve the problems of shrinkage and crack of concrete structure. Because the hydration mechanism in common concrete is different from that in concrete with low water-binder ratio, and the hydration environment is different between concrete and cement pastes, to determine the adiabatic-temperature rise of concrete directly conforms to the actual situation. The adiabatic-temperature rise, adiabatic-temperature-rise rate, hydration degree of both binders and cement are investigated by measuring adiabatic-temperature rise of concrete with different fly-ash content.

Experimental Study on Workability and Strength of Green High Performance Concrete with High Volume Fly Ash

2013 ◽  
Vol 859 ◽  
pp. 52-55 ◽  
Author(s):  
Yong Qiang Ma
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
High Volume ◽  
Ash Content ◽  
Splitting Tensile Strength ◽  
Binder Ratio ◽  
Water Binder Ratio

A great deal of experiments have been carried out in this study to reveal the effect of the water-binder ratio and fly ash content on the workability and strengths of GHPC (green high performance concrete). The workability of GHPC was evaluated by slump and slump flow. The strengths include compressive strength and splitting tensile strength. The results indicate that the increase of water-binder ratio can improve the workability of GHPC, however the strengths of GHPC were decreased with the increase of water-binder ratio. When the fly ash content is lower than 40%, the increase in fly ash content has positive effect on workability of GHPC, while the workability begins to decrease after the fly ash content is more than 40%. The addition of fly ash in GHPC has adverse effect on the strengths, and there is a tendency of decrease in the compressive strength and splitting tensile strength of GHPC with the increase of fly ash content.

Effect of High Volumes of Fly Ash on Flowability and Drying Shrinkage of Engineered Cementitious Composites

2011 ◽  
Vol 675-677 ◽  
pp. 61-64
Author(s):  
Yu Zhu ◽  
Ying Zi Yang ◽  
Yan Yao
Keyword(s):  
Fly Ash ◽  
Drying Shrinkage ◽  
Ash Content ◽  
Experimental Results ◽  
Replacement Ratio ◽  
Slump Flow ◽  
Binder Ratio ◽  
Deformation Test ◽  
Flow Deformation ◽  
Water Binder Ratio

In order to investigate flowability and drying shrinkage of ECC, mini-slump flow deformation test and drying shrinkage are employed to analyse the influence of fly ash on the flowability and shrinkage of ECC. The water-binder ratio is kept at 0.25. The replacement ratio of cement by fly ash is 50%, 60%, 70% and 80%, respectively. The experimental results show that fluidity of fresh cment paste increases obviously as the fly ash becomes larger. The drying shrinkage of ECC specimens is greatly reduced as the content of fly ash increases from 50% to 80%. The measured drying shrinkage strian of ECC specimens with 80% fly ash at 28 days is less than 1000×10-6. 25% reduction of drying shrinkage of ECC is found when the fly ash content increases from 50% to 80%.

A Comparative Study on Production of Autoclaved Aerated Concrete by Coal Gangue Fly Ash

2013 ◽  
Vol 395-396 ◽  
pp. 433-438 ◽  
Author(s):  
Ye Zhang ◽  
Peng Xuan Duan ◽  
Bao Sheng Jia ◽  
Lei Li
Keyword(s):  
Fly Ash ◽  
Ash Content ◽  
Coal Gangue ◽  
Raw Material ◽  
Autoclaved Aerated Concrete ◽  
Binder Ratio ◽  
Material Formulation ◽  
Aerated Concrete ◽  
The Common ◽  
Water Binder Ratio

In this paper, compared with common fly ash, the low-silicon coal gangue fly ash is used to produce fly ash autoclaved aerated concrete. The influences of water binder ratio, coal gangue fly ash content, calcareous content and conditioning agents on the compressive strength of the autoclaved aerated concrete are investigated. The results indicate the coal gangue fly ash has different properties from the common fly ash such as its granule appearance and the activity as AAC siliceous raw material. It is noting that the coal gangue fly ash can also be used to prepare AAC blocks by optimizing the raw material formulation and procedure and its B05 product can reach the China top industrial standard.

Research on Mix Proportion Design Method of Cement Concrete for Road Mixed with Antifreeze Admixtures Sealed in Capsules

2020 ◽  
Vol 861 ◽  
pp. 429-437
Author(s):  
Yang Zhao ◽  
Hong Fa Yu ◽  
Wei Dong Wang ◽  
Yue Li
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Design Method ◽  
Orthogonal Design ◽  
Ash Content ◽  
Material Content ◽  
Mix Proportion ◽  
Binder Ratio ◽  
Feeding Process ◽  
Water Binder Ratio

In order to explore the influence of a new mixed type antifreeze material on the flexural strength of concrete for road, the orthogonal design method was used to conduct experimental research on six factors including the water-binder ratio, the antifreeze material content, the fly ash content, the feeding process, the shape of the antifreeze material and the pre-absorption of antifreeze material. The influence degree of various factors on the flexural strength of concrete was studied, and the mixing ratio design method of concrete for road mixed with the antifreeze material was given. It was found that the water-binder ratio is the main factor affecting the strength of the concrete and that when the amount of antifreeze material is less than 15%, the effect on the strength is small. The influence of other factors on the strength is greatly influenced by the interaction of water-binder ratio. When it comes to the mix design, the content of gelling material is 500 kg/m3, and the water-binder ratio changes from 0.35 to 0.43 under different traffic levels. The recommended antifreeze material content and fly ash content is 10% and 15% respectively. It’s also suggested that the antifreeze material should be pre-absorbed, and the cement sand and stone be mixed before the antifreeze material is put into the mixing.

Influencing Factors of the Fluidity and Strength of Phosphate Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 464-468
Author(s):  
Hong Tao Wang ◽  
Ju Hui Cao ◽  
Shuang Mei Li ◽  
Ming Xue
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Retention ◽  
Natural Conditions ◽  
Slump Flow ◽  
Influence Of Water ◽  
Binder Ratio ◽  
Curing Methods ◽  
Early Strength ◽  
Water Binder Ratio

The influence of water binder ratio, content of borax and fly ash on the fluidity and strength of phosphate concrete were investigated. Results showed that the slump and slump flow of phosphate concrete improved with content of water and borax increasing. But the strength decreased, especially early strength. While the mixing amount of borax was less than 1.5% of the magnesium phosphate cement, the influence on later strength was relatively less. The fluidity decreased significantly and the cohesiveness and water retention improved while the content of fly ash was between 10% and 30%.The compressive strength increased while the content of fly ash was 10%.The better curing methods was curing in the natural conditions, the compressive increased with the age prolonged.

Theoretical and Experimental Research on Compressive Strength of High Fly-Ash Content Concrete

2011 ◽  
Vol 477 ◽  
pp. 257-262 ◽  
Author(s):  
Hong Mei Ai ◽  
Li Jiu Wang ◽  
Jing Wei ◽  
Jun Ying Bai ◽  
Pu Guang Lu
Keyword(s):  
Growth Rate ◽  
Compressive Strength ◽  
Fly Ash ◽  
Ash Content ◽  
Theoretical Formula ◽  
Term Strength ◽  
Single Factor ◽  
Binder Ratio ◽  
Water Binder Ratio

Introduced the concept of “Cementitious Coefficient” of fly ash, theoretical formula of strength of HFCC at a certain age was found with two variables: actual water-binder ratio and micro-aggregate-binder ratio. Development regularity of compressive strength of HFCC was studied and formula of long-term strength coefficient D28t was settled. Influence of actual water-binder ratio and micro-aggregate-binder ratio on long-term strength of HFCC was analyzed. Experimental results showed that along with the single-factor increase of actual water-binder ratio and micro-aggregate-binder ratio, growth rate of long-term strength of HFCC increased; influence of actual water-binder ratio was deeper than that of micro-aggregate-binder ratio.

Study on the Freezing Resistance of HFCC

2011 ◽  
Vol 308-310 ◽  
pp. 2555-2559
Author(s):  
Hong Mei Ai ◽  
Pu Guang Lu ◽  
Jun Ying Bai ◽  
Jing Jing Wei
Keyword(s):  
Fly Ash ◽  
Compression Strength ◽  
Ash Content ◽  
Freezing Resistance ◽  
Cycle Times ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Binder Ratio ◽  
Water Binder Ratio

To the High fly-ash content concrete(abbreviated HFCC) whose fly-ash adding amount is 50%~70%, the influence of actual water-binder ratio, fly-ash content, quality of fly-ash and compression strength on the freezing resistance of HFCC were studied; The critical freeze-thaw cycle times in this paper involved with mass loss rate Wn=5% and relative dynamic elastic modulus P=60%, the relationship between the critical freeze-thaw cycle times and the 28d compression strength of HFCC was analyzed; To HFCC without air-entraining agent, the experiment results showed that the freezing resistance decreased with the increase of actual water-binder ratio, the increase of fly-ash content and the reduce of fly-ash quality. The freeze-thaw damage of HFCC dues to the freeze-thaw degradation results from surface denudation.

scholarly journals Experimental Investigation and Analytical Modeling of Chloride Diffusivity of Fly Ash Concrete

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 862 ◽  
Author(s):  
Jian Zhang ◽  
Xin-Zhu Zhou ◽  
Jian-Jun Zheng ◽  
Hai-Long Ye ◽  
Jin Yang
Keyword(s):  
Fly Ash ◽  
Analytical Modeling ◽  
Volume Fraction ◽  
Ash Content ◽  
Aggregate Model ◽  
Fly Ash Concrete ◽  
Chloride Diffusivity ◽  
Binder Ratio ◽  
Water Binder Ratio ◽  
Curing Age

Owing to its importance in the assessment of reinforced concrete structures, it is essential to determine the chloride diffusivity of fly ash concrete. This paper presents an investigation into the diffusion characteristics of chloride ions in fly ash concrete. Through experiment, the relationship between chloride diffusivity and curing age up to 1800 days is measured and the effects of curing age, water/binder ratio, aggregate volume fraction, and fly ash content (i.e., percentage of total cementitious material by mass) on chloride diffusivity are evaluated. It is found that the chloride diffusivity decreases with the increase of curing age, aggregate volume fraction, and fly ash content, but increases with the increase of water/binder ratio. In analytical modeling, an equivalent aggregate model is constructed and the equivalent interfacial transition zone (ITZ) thickness is derived analytically. With the equivalent aggregate model, three-phase fly ash concrete reduces to a two-phase composite material. By extending the Maxwell method, the chloride diffusivity of fly ash concrete is formulated. Finally, the validity of the analytical method is verified by experimental results.

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