Research on Thermodynamical Performance of Concrete with Excessive Fly Ash Added in the Pile Cap of Well Tower

2011 ◽  
Vol 243-249 ◽  
pp. 6087-6092
Author(s):  
Xiang Zong ◽  
Xiang Wang
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Setting Time ◽  
Hydration Heat ◽  
Favorable Effect ◽  
Mass Concrete ◽  
Mix Proportion ◽  
Pile Cap ◽  
Time Test ◽  
Simulated Test

To meet the demand of high performance of mass concrete in a pile cap of well tower, excessive replacement of fly ash was applied to the mass concrete. Based on the theory of hydration heat of cement, several thermal parameters of mix proportion were analyzed and simulated test analyses and setting time test analyses were conducted in the laboratory. The results and data collected in the project locale both show that applying excessive replacement of fly ash reduces hydration heat of mass concrete in the pile cap of well tower, which extends setting time in mass concrete and avoids the cracks caused by temperature stress. The results achieve favorable effect and provide reference for design and construction of mix proportion in the project of mass concrete.

The Arch Support Construction and Hydration Heat Analysis of the First Bridge over Yangtze River in Hejiang

2013 ◽  
Vol 291-294 ◽  
pp. 1122-1127
Author(s):  
Yan Feng Luo ◽  
Da Yan Qin ◽  
Yun Zhang
Keyword(s):  
Yangtze River ◽  
Casting Process ◽  
Hydration Heat ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Element Analysis ◽  
Early Hydration ◽  
Mix Proportion ◽  
Arch Support ◽  
Heat Preservation

The arch support of the First Bridge over Yangtze River in Hejiang used the stratified and graded casting process in mass concrete pouring process. By means of optimizing the concrete mix proportion design, using high mixing amount of fly ash concrete, reducing heat release rate of concrete early hydration heat, delaying the time of maximum temperature rise, and combining turn-over forms and water storage and other surface heat preservation measures, the temperature difference between inside and outside concrete was reduced and the cracking of mass concrete was avoided. Finite element analysis of hydration heat was done to verify the feasibility of the construction scheme.

Physical Properties of Volcanic Ash Based Geopolymer Concrete

2016 ◽  
Vol 841 ◽  
pp. 1-6 ◽  
Author(s):  
Puput Risdanareni ◽  
Adjib Karjanto ◽  
Febriano Khakim
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Physical Properties ◽  
Volcanic Ash ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Ash Content ◽  
Geopolymer Concrete ◽  
Split Tensile Strength ◽  
Time Test

This paper describes the result of investigating volcanic ash of Mount Kelud as fly ash substitute material to produce geopolymer concrete. The test was held on geopolymer concrete blended with 0%, 25%, 50% and 100% fly ash replacement with volcanic ash. Natrium Hidroxide (NaOH) with concentration of 12 molar and Natrium Silicate (Na2SiO3) were used as alkaline activator. While alkali-activator ratio of 2 was used in this research. The physical properties was tested by porosity and setting time test, while split tensile strength presented to measure brittle caracteristic of geopolymer concrete. The result shown that increasing volcanic ash content in the mixture will increase setting time of geopolymer paste. On the other hand increasing volcanic ash content will reduce split tensile strength and porosity of geopolymer concrete. After all replacing fly ash with volcanic ash was suitable from 25% to 50% due to its optimum physical and mechanical properties.

Research on the Application of Slipform Concrete of Well Tower in winter

2012 ◽  
Vol 204-208 ◽  
pp. 3703-3706
Author(s):  
Xiang Zong
Keyword(s):  
Mechanical Performance ◽  
Setting Time ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Mix Proportion ◽  
Time Test ◽  
Early Strength ◽  
Blend Ratios

To meet the demand of performance of slipform concrete in a well tower in winter, different blend ratios of early strength water reducing agents were added to the concrete. Compared with reference concrete, their setting time test analyses, workability analyses and tests of mechanical performance and removal of forms were conducted in the laboratory. The results show that concrete with FS-A early strength water reducing agent can greatly improve early strength of concrete and meet the demand of relevant performance of slipform. This research may provide reference for design of mix proportion and construction in similar slipform project.

Mechanical Properties Test Research on Mass Concrete Mixed with Different Fly Ash Bulk Volume

2012 ◽  
Vol 204-208 ◽  
pp. 3664-3667
Author(s):  
Jing Hong Liu ◽  
Xiao Hua Liu ◽  
Wen Han
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Hydration Heat ◽  
Mass Concrete ◽  
Test Results ◽  
Fly Ash Concrete ◽  
Mechanics Performance ◽  
Bulk Volume ◽  
Strength And Durability ◽  
Tensile Strain Capacity

The concrete would crack when the temperature stress caused by hardening concrete hydration heat and shrinkage action were over the concrete’ tensile strength. The concrete were added with different amount of fly ash in order to increase concrete’ tensile strength and ultimate tensile strain capacity or consider economic perspective. The mechanics performance tests were carried on mass concrete with different fly ash bulk volume. The test results showed that the fresh fly ash concrete’ workability, hydration heat, compressive strength and durability were obvious superior compared with ordinary concrete.

A Study of the Preparation and Properties of the Concrete for the Bearing Platform of the Xiamen-Zhangzhou Sea-Spanning Bridge

2013 ◽  
Vol 357-360 ◽  
pp. 659-666
Author(s):  
Hong Mei Hu ◽  
Hao Wang ◽  
Rong Gui Du ◽  
Bo Shen Zheng ◽  
Yun Kun Yi ◽  
...  
Keyword(s):  
Fly Ash ◽  
Optimal Design ◽  
Environmental Conditions ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Diffusion ◽  
Mass Concrete ◽  
Concrete Mix ◽  
Marine Concrete ◽  
Main Bridge

In light of the requirement of mass concrete for the bearing platform of the main tower of the Beicha Main Bridge of the Xiamen-Zhangzhou Sea-spanning Bridge, and in view of the hostile environmental conditions for the project, a study was conducted on the technology of preparing high-performance marine concrete for the bearing platform of the sea-spanning bridge in order to control concrete temperatures and achieve the desired durability for the bridge. With an optimal design which features the binary admixture of fly ash and slag and an optimal concrete mix ratio, high-performance concrete with lower hydration heat and strong resistance to chloride diffusion and cracking was successfully developed for the bearing platform of the sea-spanning bridge.

Study on the Effect of Fly Ash Mix Amount in Large Volume Pile Cap Concrete on Heat of Hydration

2015 ◽  
Vol 744-746 ◽  
pp. 832-836
Author(s):  
Hai Liang Wang ◽  
Xie Dong Zhang
Keyword(s):  
Finite Element ◽  
Fly Ash ◽  
Temperature Control ◽  
Large Volume ◽  
Yellow River ◽  
Heat Of Hydration ◽  
Raw Material ◽  
Finite Element Software ◽  
Mix Proportion ◽  
Pile Cap

Contraposed the hydration heat of large volume concrete, based on the introduces of raw material, the effect of fly ash mix amount in large volume pile cap concrete was mainly analyzed combined with project case of Yellow River Bridge in Baotou-Shulinzhao Highway. Moreover the temperature and temperature stress in different mix amounts were analyzed by the finite element software to confirm the appropriate mix amount of fly ash and the mix proportion of concrete. Finally, the consequence of the large volume pile cap temperature control was certified by the practice of construction.

Experimental Study on the Impact of Admixture for Concrete Heat of Hydration and Early-Age Contractile Properties

2012 ◽  
Vol 253-255 ◽  
pp. 385-389 ◽  
Author(s):  
Jian Cheng Sun ◽  
Bo Jun Wang ◽  
Wen Zhong Zhao
Keyword(s):  
Experimental Study ◽  
Fly Ash ◽  
Concrete Structure ◽  
Autogenous Shrinkage ◽  
Heat Of Hydration ◽  
Reducing Agent ◽  
Hydration Heat ◽  
Early Age ◽  
Mix Proportion ◽  
Structure Crack

During the technology development of modem concrete, concrete structure crack (especially early-age crack) becomes more and more serious and has been one of main research directions of civil engineering. This paper aims at the seriousness of concrete structure crack and presents one of main cause is that concrete early-age (especially autogenous shrinkage) become large through the experimental study. autogenous shrinkage are mainly belongs to temperature cracks and desiccation cracks. Analyses the affection of ash and water reducing agent on the hydration heat, under the optimum proportion experiment which aims at reducing he hydration heat of cement. The best program are obtained that double mix with 20% fly ash and 1.5% water reducing agent .Design mortar’s early anti-crack experiment, and study crack-resistance and other mechanical properties based on different ages & different mix proportion. From the experiment, analyses early cracking under the influence of admixtures. The mix proportion of 20% fly ash, 10% slag and 1.2% water reducing agent can minimize the creation of cracks.

A Development of the Research on High Performance Concrete Incorporated with High Volume Fly Ash

2006 ◽  
Vol 302-303 ◽  
pp. 26-34
Author(s):  
Feng Xing ◽  
Xiang Yong Guo ◽  
Fa Guang Leng ◽  
Ren Yu Zhang
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
High Performance Concrete ◽  
High Volume ◽  
Raw Material ◽  
Engineering Practice ◽  
Fly Ash Concrete ◽  
Mix Proportion ◽  
High Volume Fly Ash ◽  
And Performance

In this paper, the main characteristic of definition, property, requirement of raw material, mix proportion design and performance improvement of high volume fly ash concrete (for short HVFAC) are summarized. The applications of HVFAC in dam, highway, building and port are introduced. The research results have shown that HVFAC have outstanding properties of physical mechanics, but some problems need to be further studied. It is believed that an operable strict corresponding technical criterion would be set down as soon as possible for engineering practice.

Utilization of Phosphorus Slag and Fly Ash for the Preparation of Ready-Mixed Mortar

2013 ◽  
Vol 423-426 ◽  
pp. 987-992 ◽  
Author(s):  
Xiu Wei Liu ◽  
Lin Yang ◽  
Bin Zhang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Raw Materials ◽  
Setting Time ◽  
Technological Parameters ◽  
Mix Proportion ◽  
Optimal Mix ◽  
Mixed Mortar ◽  
Chinese Standard ◽  
Phosphorous Slag

Phosphorous slag and fly ash were used as raw materials for the preparation of ready-mixed mortar, and a series of technological parameters, such as phosphorus slag content, fly ash content, and chemical activators were investigated based on the compressive strength and setting time of specimens in this paper and the performances of products were also tested. The results showed that the optimal mix proportion for preparing ready-mixed mortar (M10) is as follows: cement 5%, phosphorous slag 10%, fly ash 10%, sand 75%, water reducer 1% and chemical activator 1%. The consistency, water retaining, setting time, 28d compressive strength, 14d bond strength and 28d shrinkage meet the requirement of Chinese standard GB/T 25181-2010.

A Novel Technique for Crack Resistance of Bulk Mass Concrete Pier

2011 ◽  
Vol 383-390 ◽  
pp. 1719-1724
Author(s):  
H.B. Zhu ◽  
P.M. Wang ◽  
G. T. Yan ◽  
C.S. Wang ◽  
Y.S. Cheng ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Hydration Heat ◽  
Shrinkage Stress ◽  
Mass Concrete ◽  
Granulated Blast Furnace Slag ◽  
Bulk Mass ◽  
Higher Temperature ◽  
Furnace Slag

The bulk mass concrete pier is esay to crack because of higher temperature contrast between inner and outer of concrete. Experimentation use admixtures to replace some of cement so as to low the hydration heat. Fly ash can decrease more hydration heat than granulated blast furnace slag. If 40 percent of cement in weight is replaced by same amount of blend admixture of fly ash and granulated blast furnace slag, not only the compression strength can meet the requirement of engineering design, but also the hydration heat reduce a lot. Meanwhile, this paper develops a novel lining fabric especially for concrete steel formwork to advance water-retaining property and warm-keeping efficiency, and to distract shrinkage stress by ways of veins of fabric. Because of developed lining fabric and optimized mixture in this paper, the cracking problem of bulk mass concrete pier is avoided.

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