Modeling the Heat of Hydration of Concrete Incorporating Fly Ash

2016 ◽  
Vol 705 ◽  
pp. 332-337 ◽  
Author(s):  
Zheng Gang Lu ◽  
Xiu Xin Wang
Keyword(s):  
Fly Ash ◽  
Temperature Rise ◽  
Heat Of Hydration ◽  
Hyperbolic Type ◽  
Adiabatic Temperature ◽  
Adiabatic Temperature Rise ◽  
Equivalent Age ◽  
Binder Ratio ◽  
Water Binder Ratio ◽  
Release Coefficient

The hydration evolution of concrete with different water-binder ratios and fly ash replacement percentages are studied by experimental investigation. Based on equivalent age concept, the effect of water-binder ratio as well as fly ash dosage on the ultimate temperature rise and heat release coefficient are analyzed with the hyperbolic-type calculating model of adiabatic temperature rise adopted. It is indicated that the adiabatic temperature rise will be reduced with the increase of water-binder ratio and the incorporation of fly ash. The hydration evolution process will be accelerated with the decrease of water-binder ratio, but slowed down when the amount of fly ash is enhanced.

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.

scholarly journals Effects of Different Content of Phosphorus Slag Composite Concrete: Heat Evolution, Sulphate-Corrosion Resistance and Volume Deformation

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1293
Author(s):  
Kuisheng Liu ◽  
Yong Cui
Keyword(s):  
Temperature Rise ◽  
Control Sample ◽  
Drying Shrinkage ◽  
Strength Loss ◽  
Adiabatic Temperature ◽  
Adiabatic Temperature Rise ◽  
Binder Ratio ◽  
L 22 ◽  
Water Binder Ratio

Phosphorus slag (PS) and limestone (LS) composite (PLC) were prepared with a mass ratio of 1:1. The effects of the content of PLC and the water/binder ratio on the mechanical properties, durability and dry shrinkage of concrete were studied via compressive strength, electric flux, sulfate dry/wet cycle method, saturated drainage method, isothermal calorimeter, adiabatic temperature rise instrument and shrinkage deformation instrument. The results show that PLC can greatly reduce the adiabatic temperature rise of concrete. The adiabatic temperature rise is 55 °C with 33 wt.% PLC, 10 °C lower than that of the control sample. The addition in the content of PLC does not affect the long-term strength of concrete. When the water/binder ratio decreases by 0.1–0.15, the long-term strength of concrete with PLC increases by about 10%, compared with the control group. At the age of 360 days, the chloride permeability of L-11 (i.e., the content of PLC was 20%, the water/binder ratio was 0.418) and L-22 (i.e., the content of PLC was 33%, the water/binder ratio was 0.39) decrease to the “very low” grade. The strength loss rate of L-11 and L-22 after 150 sulfate dry/wet cycles is about 18.5% and 19%, respectively, which is 60% of the strength loss rate of the control sample. The drying shrinkage of L-11 and L-22 reduces by 4.7% and 9.5%, respectively, indicating that PLC can also reduce the drying shrinkage.

scholarly journals Strength Development and Thermogravimetric Investigation of High-Volume Fly Ash Binders

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3344 ◽  
Author(s):  
Zhiyuan Zhou ◽  
Massoud Sofi ◽  
Elisa Lumantarna ◽  
Rackel San Nicolas ◽  
Gideon Hadi Kusuma ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Temperature Rise ◽  
Bound Water ◽  
High Volume ◽  
Heat Of Hydration ◽  
New Method ◽  
Hydration Properties ◽  
Adiabatic Temperature Rise ◽  
High Volume Fly Ash

To address sustainability issues by facilitating the use of high-volume fly ash (HVFA) concrete in industry, this paper investigates the early age hydration properties of HVFA binders in concrete and the correlation between hydration properties and compressive strengths of the cement pastes. A new method of calculating the chemically bound water of HVFA binders was used and validated. Fly ash (FA) types used in this study were sourced from Indonesia and Australia for comparison. The water to binder (w/b) ratio was 0.4 and FA replacement levels were 40%, 50% and 60% by weight. Isothermal calorimetry tests were conducted to study the heat of hydration which was further converted to the adiabatic temperature rise. Thermo-gravimetric analysis (TGA) was employed to explore the chemically bound water (WB) of the binders. The results showed that Australian FA pastes had higher heat of hydration, adiabatic temperature rise, WB and compressive strength compared to Indonesian FA pastes. The new method of calculating chemically bound water can be successfully applied to HVFA binders. Linear correlation could be found between the WB and compressive strength.

Influence of Casting Temperature on the Heat of Hydration in Mass Concrete Foundation with Ternary Cements

2014 ◽  
Vol 525 ◽  
pp. 478-481 ◽  
Author(s):  
Mi Hwa Lee ◽  
Young Seok Chae ◽  
Bae Su Khil ◽  
Hyun Do Yun
Keyword(s):  
Temperature Rise ◽  
Heat Of Hydration ◽  
Adiabatic Temperature ◽  
Casting Temperature ◽  
Mass Concrete ◽  
External Temperature ◽  
Maximum Heat ◽  
Adiabatic Temperature Rise ◽  
Concrete Foundation ◽  
Mat Foundation

This study is conducted to evaluate analytically the effect of casting temperature on the heat of hydration in mass concrete foundation with ternary cements and Type IV low heat cement. The mat foundation has the dimension of 15m length, 20m width and 3m depth. Casting temperatures considered for mat foundation consist of 10, 20 and 30C ̊. A commercial software MIDAS/Gen was used to analyze the hydration heat of mass concrete foundation. The maximum adiabatic temperature rise (K), and the coefficient of temperature rise˰˸α˹˰for thermal analysis were drawn from adiabatic temperature rise test. Analytical results show that blended cement PSLB_352 is the most effective to control the heat of hydration in mass concrete foundation and external temperature increases the maximum heat of hydration and crack probability of mat foundation with mass concrete.

Experimental Study on Influential Factors of Adiabatic Temperature Rise for Mass Concrete

2011 ◽  
Vol 306-307 ◽  
pp. 917-922
Author(s):  
Dong Dong Wang ◽  
Wei Li Tian ◽  
Cheng Qi Wang
Keyword(s):  
Temperature Rise ◽  
Heat Liberation ◽  
Influential Factors ◽  
Adiabatic Temperature ◽  
Mineral Admixtures ◽  
Mass Concrete ◽  
Adiabatic Temperature Rise ◽  
Exothermic Process ◽  
Binder Ratio ◽  
Main Factor

Experiments on adiabatic temperature rise are systematically carried out in this paper, the characteristics of adiabatic temperature rise of concrete with different mineral admixtures are compared. The influence of binder amount, water-binder ratio, placing temperature and superplasticizer is also studied. The results reflect that binder is the main factor affecting adiabatic temperature rise, mineral admixtures such as fly ash can significantly reduce the rate and amount of heat development, large quantity substitution of slag in concrete can relieve the concentrative heat liberation, the retarded superplasticizer can prolong the exothermic process effectively and high placing temperature has adverse effect on temperature control of mass concrete.

Thermal Characteristics of Mat Foundation with Different Lift Thickness of Mass Concrete Including Strontium-Based Latent Heat Binder

2014 ◽  
Vol 525 ◽  
pp. 461-464
Author(s):  
Kyung Lim Ahn ◽  
Qi Bo Liang ◽  
Bae Su Khil ◽  
Hyun Do Yun
Keyword(s):  
Latent Heat ◽  
Temperature Rise ◽  
Volume Fraction ◽  
Heat Of Hydration ◽  
Adiabatic Temperature ◽  
Hydration Heat ◽  
Mass Concrete ◽  
Adiabatic Temperature Rise ◽  
Concrete Foundation ◽  
Mat Foundation

This study provides analytical results for heat of hydration in the mat foundation with mass concretes to investigate the effect of lift thickness in the mat foundation on the hydration heat and crack characteristics of mat foundation with mass concrete. Mass concretes were mixed with ternary cement with 1% strontium-based latent heat binder at volume fraction and Type IV low heat cement. The mat foundation has the dimension of 15m length, 20m width and 3m depth. Lift thickness of mass concrete for mat foundation was varied from 1.0m to 3.0m. A commercial software MIDAS/Gen was used to analyze the hydration heat of mass concrete foundation. The maximum adiabatic temperature rise (K), and the coefficient of temperature rise (α) for thermal analysis were drawn from adiabatic temperature rise test. Based on the results of the finite element analysis for mat foundation with different lift thickness, the highest internal temperature and thermal stress increased with increasing with lift thickness of foundation. However, for foundation constructed with premixed strontium based latent heat binder (PSLB) concrete, this phenomenon was less remarkable compared to mass concrete foundation made with low heat cement.

scholarly journals Partially Replacing Fly Ash with Limestone Powder in the Paste - Influence and Characterization

2015 ◽  
Vol 9 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Lv Wenyu ◽  
Zhang Zhihui
Keyword(s):  
Shear Strength ◽  
Fly Ash ◽  
Temperature Rise ◽  
Frost Resistance ◽  
Setting Time ◽  
Research Direction ◽  
Adiabatic Temperature ◽  
Limestone Powder ◽  
Adiabatic Temperature Rise ◽  
Dry Shrinkage

Paste filling is an important research direction of coalmine “green mining” which can dispose coalmines solid waste and achieve environmental protection. The mechanical properties such as compressive strength, workability, ultimate tension value, shear strength and splitting strength of paste, in which the fly ash was partially replaced by limestone powder, was studied. Adiabatic temperature rise, setting time, shear strength, permeability, frost resistance and dry shrinkage of different substitution rate were investigated and the results were compared with traditional paste. The test results showed that the influence of limestone powder on workability, permeability and frost resistance performance of paste was slight, the setting time of paste were shortened, adiabatic temperature rise and mechanics performance of paste were decreased, dry shrinkage value was increased with limestone powder content increasing.

A Study on the Influence of Fly Ash on the Thermal Parameters of Shrinkage Compensating Concrete

2018 ◽  
Vol 768 ◽  
pp. 336-340
Author(s):  
Yu Chuan Jiang ◽  
Je Xu ◽  
Bao Cheng Zhao ◽  
Yang Wang
Keyword(s):  
Thermal Conductivity ◽  
Fly Ash ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Significant Influence ◽  
Temperature Rise ◽  
Thermal Parameters ◽  
Adiabatic Temperature ◽  
Adiabatic Temperature Rise ◽  
Air Content

This paper studies the adiabatic temperature rise, specific heat, thermal conductivity and thermal diffusivity of shrinkage compensating concrete mixed with 18%, 23%, 30% and 40% fly ash. The results present that fly ash has significant influence on the process of the adiabatic temperature rise, and the influence on the specific heat is little. The adiabatic temperature rise of 14d will be lower as the fly ash content is higher. There is significant influence of air content on thermal conductivity and thermal diffusivity, and the fly ash is little. Further research on the thermal parameters of shrinkage compensating concrete is needed.

Effect of Slag Characteristics on Adiabatic Temperature Rise of Blended Concrete

2022 ◽  
Author(s):  
Hai Zhu ◽  
Dhanushika Gunatilake Mapa ◽  
Catherine Lucero ◽  
Kyle A. Riding ◽  
A. Zayed
Keyword(s):  
Temperature Rise ◽  
Adiabatic Temperature ◽  
Adiabatic Temperature Rise
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