Abstract
The hydration characteristics of cement in hardened cement paste, mortar and concrete were investigated and discussed from the stand points of hydration degree, pore structure, composition and structure of hydrates. In hardened cement pastes, area proportion of a darkest part in the back scattered electron image of its polished surface closely correlated with the volume of pores more than 50nm in diameter. In the cases of hardened mortar and concrete, however, the abovementioned correlation was not so good, since they had additional porous structures called a transitional zone, which was composed of Ca(OH)2 precipitated around aggregate grains. Dense C-S-H layer in hardened mortar and concrete formed around unhydrated alite was thicker and its average Ca/Si molar ratio was by 0.2 lower than that of hardened cement paste. This phenomenon is considered to be caused by the low Ca ion concentration in a liquid phase due to the presence of an aggregate, by the high degree of hydration of cement and by local precipitation of Ca(OH)2 around an aggregate in hardened mortar and concrete.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
