A Prediction Model of Adiabatic Temperature Rise for Mass Concrete Containing Fly Ash in The Southeast Asia Region
Fly ash is one of the pozzolanic materials widely used in concrete which improves workability, physical properties including long-term strength and durability and provides reduction in temperature rise.The use of fly ash also contributes to reduce environmental load as a reduction of solid waste to be landfilled.However, concrete containing fly ash has some problems such as reduction in air entrainment and low early strength development in areas with cold seasons including Japan.On the other hand, these problems can be insignificant in Southeast Asia region where climate is warm.In addition, the replacement of cement with fly ash can reduce the temperature rise by heat of cement hydration.Therefore, fly ash concrete is sometimes used for mass concrete structures to prevent thermal cracking.The aim of this study is to find equations for estimating adiabatic temperature rise in concrete containing fly ash.The cementitious material used in the study consisted of ordinary Portland cement and fly ash, and mixing of concrete was done at 27 degrees Celsius.Measurement of adiabatic temperature rise of concrete using fly ash cement with a replacement ratio of 15% to 50% was carried out, and equations were established based on these experimental results when concrete was mixed at 27 degrees Celsius.The equations consist of ultimate adiabatic temperature rise and parameters representing rate of adiabatic temperature rise as functions of ordinary Portland cement unit content.Prediction results were in good agreement with the measured results, showing that the effect of fly ash which was used in this study on early temperature rise of concrete could be insignificant and contribute to reduction of cement unit content.Semi-adiabatic temperature rise in 40 cm cubic specimens was measured in the laboratory, and the results were compared with prediction results by three-dimensional finite element analysis using the equations established in this study.It was found that predicted temperature histories showed a high accuracy against the measured results.Furthermore, another analysis was conducted for verification of this prediction model by using mock up test results in Singapore, and the analysis results also showed a high accuracy.Consequently, the equations proposed for estimating adiabatic temperature rise in concrete containing fly ash would be useful for prediction of temperature rise at the center of actual mass concrete structure.
Adiabatic temperature rise Finite element analysis Fly ash Mass concrete Prediction model
K.Mori K.Tada E.Yasuda
Central Research Laboratory, Taiheiyo Cement Corporation, Chiba, Japan
国际会议
福州
英文
375-382
2018-11-04（万方平台首次上网日期，不代表论文的发表时间）