Microstructural and bulk property changes in hardened cement paste during the first drying process

Journal Article · Tue Apr 01 00:00:00 EDT 2014 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2014.01.007· OSTI ID:22323131

Maruyama, Ippei ^[1]; Nishioka, Yukiko; Igarashi, Go ^[2]; Matsui, Kunio ^[3]

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1. Graduate School of Environmental Studies, Nagoya University, ES Building, No. 546, Furo-cho, Chikusa-ku, Nagoya 464–8603 (Japan)
2. Graduate School of Environmental Studies, Nagoya University, ES Building, No. 539, Furo-cho, Chikusa-ku, Nagoya 464–8603 (Japan)
3. Products and Marketing Development Dept. Asahi-KASEI Construction Materials Corporation, 106 Someya, Sakai-machi, Sashima-gun, Ibaraki, 306–0493 (Japan)

This paper reports the microstructural changes and resultant bulk physical property changes in hardened cement paste (hcp) during the first desorption process. The microstructural changes and solid-phase changes were evaluated by water vapor sorption, nitrogen sorption, ultrasonic velocity, and {sup 29}Si and {sup 27}Al nuclear magnetic resonance. Strength, Young's modulus, and drying shrinkage were also examined. The first drying process increased the volume of macropores and decreased the volume of mesopores and interlayer spaces. Furthermore, in the first drying process globule clusters were interconnected. During the first desorption, the strength increased for samples cured at 100% to 90% RH, decreased for 90% to 40% RH, and increased again for 40% to 11% RH. This behavior is explained by both microstructural changes in hcp and C–S–H globule densification. The drying shrinkage strains during rapid drying and slow drying were compared and the effects of the microstructural changes and evaporation were separated.

• OSTI ID: 22323131
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 58; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALUMINIUM 27
CALCIUM SILICATES
CEMENTS
DESORPTION
DRYING
EVAPORATION
FLEXURAL STRENGTH
HCP LATTICES
HYDRATES
MICROSTRUCTURE
NITROGEN
NUCLEAR MAGNETIC RESONANCE
PHYSICAL PROPERTIES
SHRINKAGE
SILICON 29
SOLIDS
SURFACE AREA
WATER VAPOR
YOUNG MODULUS