RT Journal Article
T1 Calcium aluminate cement conversion analysed by ptychographic nanotomography
A1 Shirani, Shiva
A1 Cuesta-García, Ana María
A1 Gómez-de-la-Torre, María de los  Ángeles
A1 Díaz, Ana
A1 Trtrik, Pavel
A1 Holler, Mirko
A1 García-Aranda, Miguel Ángel
K1 Cemento - Aditivos
K1 Cemento - Densidad
K1 Construcción
AB Calcium aluminate cements are used for special applications but are nowadays banned for generalstructural purposes due to the calcium aluminate hydrate conversion, that has led, for concretesfabricated with high water contents, to building collapses. The stoichiometries of these conversionchemical reactions are relatively well established but the consequences in porosity, key to predictdurability, were unknown. Here, we have used hard X-ray ptychographic nanotomography to studythe hydration of CaAl2O4 at different temperatures and chiefly, at 4ºC and then at 50ºC to provokeconversion similar to field conditions. The mass densities of the resulting Al(OH)3 gels were 1.94,1.98 and 2.23 g.cm-3, for samples hydrated at 4, 20 and 50ºC, respectively. These values are lowerthan that of gibbsite, 2.42 g.cm-3. Above all, this 3D imaging technique has allowed measuring thesecondary water porosity developed in the conversion, which has an average pore dimension closeto 140 nm.
PB Elsevier
YR 2020
FD 2020-08-17
LK https://hdl.handle.net/10630/19991
UL https://hdl.handle.net/10630/19991
LA eng
NO Cement and Concrete Research 137 (2020) 106201
NO Financial support from BIA2017-82391-R research grant, which is co-funded by FEDER, is gratefully acknowledged.
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 20 ene 2026