RT Journal Article
T1 The role of sodium and sulfate sources on the rheology and hydration of  C3A polymorphs
A1 Neto, José da Silva Andrade
A1 Gómez-de-la-Torre, María de los  Ángeles
A1 Campos, Carlos E. M.
A1 Gleize, Philippe J. P.
A1 Monteiro, Paulo J. M.
A1 Kirchheim, Ana Paula
A1 Martos, Paulo R. de
K1 Reología
K1 Hidratación
K1 Cemento
AB The higher reactivity of orthorhombic C3A (ort-C3A) in sulfate-containing solutions, compared with cubic C3A (cb-C3A), was previously related to the differences in crystal structure or the sodium in the ort-C3A pore solution. We analyzed the hydration of cb-C3A (in water and NaOH solution) and Na-doped ort-C3A in the presence of gypsum and hemihydrate. Calorimetry, in-situ XRD, TGA, and rheological tests were conducted. NaOH accelerated the hydration of cb-C3A, but ort-C3A still presented higher ettringite formation rate and earlier sulfate depletion. Ort-C3A pastes showed 10-20 times higher viscosities and yield stresses. Replacing gypsum by hemihydrate increased the ettringite precipitation rate and anticipated the sulfate depletion of ort-C3A but did not significantly influence cb-C3A hydration. The crystallization of hemihydrate into gypsum resulted in early (<10 min) stiffing of all C3A-hemihydrate pastes. Overall, the higher reactivity of ort-C3A is related to differences in crystal structure rather than the sodium in the pore solution.
PB Elsevier
YR 2022
FD 2022
LK https://hdl.handle.net/10630/23199
UL https://hdl.handle.net/10630/23199
LA eng
NO Cement and Concrete Research, Volume 151, January 2022, 106639
NO JSAN, PRM, and PJPG thanks the financial support of CAPES (Coordinationfor the Improvement of Higher Education Personnel)[88882.439908/2019-01]. JSAN thanks the University of Malaga(Spain), where the experiments for the characterization of the raw materialswere performed. JSAN and AGdT also thank the Spanish Junta deAndalucía [P18-RT-720] research project for the research stage at theUniversity of M´alaga (Spain) and the Graduate Program in Civil Engineering:Construction and Infrastructure (PPGCI) of the Federal Universityof Rio Grande do Sul (UFRGS). PRM and PJPG thank theBrazilian funding agency FAPESC. The participation APK and CEMCwere sponsored by CNPq (Brazilian National Council for Scientific andTechnological Development) through the research fellowships PQ2017305530/2017- 8 and PQ2019 304756/2019-9. The in-situ XRD datacollection was carried out by PRM and CEMC at Laborat´orio de Difraç˜aode Raios-X (LDRX-UFSC). Ms. Patrícia Prates from Laborat´orio deMateriais (LabMAT-UFSC) is kindly acknowledged for the assistance inthe SEM analysis.
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 24 ene 2026