Hydration Characteristics of Low-Heat Cement Substituted by Fly Ash and Limestone Powder

Materials

Si-Jun Kim¹  Keun-Hyeok Yang¹  Gyu-Don Moon² 

[1]Department of Plant Architectural Engineering, Kyonggi University, Suwon, Kyonggi-do 16227, Korea

[2] E-Mail:

[3]Department of Architectural Engineering, Kyonggi University, Graduate School, Suwon, Kyonggi-do 16227, Korea

[4] E-Mail:

关键词: low-heat cement;    fly ash;    limestone powder;    heat of hydration;    pore size;   

DOI  :  10.3390/ma8095277

来源: mdpi

【 摘 要 】

This study proposed a new binder as an alternative to conventional cement to reduce the heat of hydration in mass concrete elements. As a main cementitious material, low-heat cement (LHC) was considered, and then fly ash (FA), modified FA (MFA) by vibrator mill, and limestone powder (LP) were used as a partial replacement of LHC. The addition of FA delayed the induction period at the hydration heat curve and the maximum heat flow value (q_max) increased compared with the LHC based binder. As the proportion and fineness of the FA increased, the induction period of the hydration heat curve was extended, and the q_max increased. The hydration production of Ca(OH)₂ was independent of the addition of FA or MFA up to an age of 7 days, beyond which the amount of Ca(OH)₂ gradually decreased owing to their pozzolanic reaction. In the case of LP being used as a supplementary cementitious material, the induction period of the hydration heat curve was reduced by comparison with the case of LHC based binder, and monocarboaluminate was observed as a hydration product. The average pore size measured at an age of 28 days was smaller for LHC with FA or MFA than for 100% LHC.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.