Prediction model for internal relative humidity in early-age concrete under different curing humidity conditions

This paper focuses on the impact which polypropylene fiber (PF) has on the self-desiccation effect at early age of high performance concrete (HPC). The experimental results indicate that PF has little influence on the Internal Relative Humidity (IRH) caused by self-desiccation effect of concrete, but can reduce early aged self-desiccation shrinkage of concrete. With the PF dosage increasing, the values of early self-desiccation shrinkage of HPC decrease first and then increase. In the experimental conditions, the value of self-desiccation shrinkage of concrete with 0.6Kg/m3 PF is the lowest one.

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Prediction Model of Internal Relative Humidity During Self-desiccation in Hardened Cement Pastes

Concrete Research and Technology ◽

10.3151/crt.26.11 ◽

2015 ◽

Vol 26 (0) ◽

pp. 11-19 ◽

Cited By ~ 1

Author(s):

Hideyuki Utsumi ◽

Takehiro Misaka ◽

Wataru Moteki

Keyword(s):

Relative Humidity ◽

Prediction Model ◽

Hardened Cement ◽

Cement Pastes ◽

Internal Relative Humidity ◽

Hardened Cement Pastes

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Thermal conductivity evolution of early-age concrete under variable curing temperature: Effect mechanism and prediction model

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.126078 ◽

2022 ◽

Vol 319 ◽

pp. 126078

Author(s):

Bofu Chen ◽

Bin Guan ◽

Xiaochun Lu ◽

Bin Tian ◽

Yangbo Li

Keyword(s):

Thermal Conductivity ◽

Prediction Model ◽

Temperature Effect ◽

Curing Temperature ◽

Early Age ◽

Effect Mechanism ◽

Early Age Concrete

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Internal Relative Humidity and Drying Shrinkage of Lightweight Aggregate Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.629-630.473 ◽

2014 ◽

Vol 629-630 ◽

pp. 473-480

Author(s):

Xiu Hua Zheng ◽

Yu Feng Zhai ◽

Shi Zuo Zhan ◽

Shu Jie Song

Keyword(s):

Relative Humidity ◽

Early Stage ◽

Drying Shrinkage ◽

Lightweight Aggregate ◽

Lightweight Aggregate Concrete ◽

Early Age ◽

Aggregate Concrete ◽

Cement Ratio ◽

Air Content ◽

Internal Relative Humidity

In this paper, the influence of water cement ratio, prewetting degree of lightweight aggregate, flyash content and air content on the internal relative humidity (IRH) and drying shrinkage of lightweight aggregate concrete (LAC) were studied using a relative humidity sensor and drying shrinkage apparatus. Results showed that the IRH of concrete decreased rapidly at early age and slowed down at late age, and prewetting lightweight aggregate could compensate the loss of IRH. The effect of compensation could be enhanced with the increasing of prewetting degree of lightweight aggregate, and the addition of flyash retarded the decrease of IRH at early age. The drying shrinkage of LAC increased quickly at early stage and it slowed down to the even after 60 days or longer age. Furthermore, the drying shrinkage of LAC increased with increasing of water cement ratio. The effect of air content on the drying shrinkage of LAC was limited at early stage. However, at the late stage it grew at different level with increasing of air content. By raising the prewetting degree of lightweight aggregate, mixing with proper dosage of flyash, the shrinkage rate of LAC can be reduced markedly. Key words: lightweight aggregate concrete, internal relative humidity, drying shrinkage, prewetting degree, flyash.

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