Theme-Logo
  • Login
  • Home
  • Course
  • Publication
  • Theses
  • Reports
  • Published books
  • Workshops / Conferences
  • Supervised PhD
  • Supervised MSc
  • Supervised projects
  • Education
  • Language skills
  • Positions
  • Memberships and awards
  • Committees
  • Experience
  • Scientific activites
  • In links
  • Outgoinglinks
  • News
  • Gallery
publication name BEHAVIOR OF DELAYED ADDITION TIME OF SNF SUPERPLASTICIZER ON MICROSILICA-SULPHATE RESISTING CEMENTS
Authors H. El-Didamony, Mohamed Heikal, I. Aiad, S. Al-Masry
year 2013
keywords
journal
volume Not Available
issue Not Available
pages Not Available
publisher Not Available
Local/International International
Paper Link http://www.ceramics-silikaty.cz/2013/2013_03_232.htm
Full paper download
Supplementary materials Not Available
Abstract

Most concrete produced today includes either chemical additions or chemical admixtures added to concrete, or both. These additives alter the properties of cementitious systems, including fluidity, hydration kinetics, microstructure and strength. Therefore, the development and use of the most suitable type, optimum dosage and delayed addition time (DAT) of superplasticiser in concrete technology have been of increasing importance. The present investigation aimed to evaluate the influence of DAT of sulfonated naphthalene formaldehyde (SNF) condensate on the hydration kinetics of sulfate resisting cement (SRC) pastes incorporating 10 mass % silica fume (SF). Superplasticized cement pastes were prepared using the required water of standard consistency with different dosages and DAT of SNF. The pastes were hydrated for 90 days under normal curing conditions. The results revealed that, the fluidity of cement pastes increases with SNF content and DAT up to 7.5 minutes, due to the electrostatic repulsion between cement particles and the decrease of anhydrous C3A content that is minimized with hydration time. Also, the chemical and physico-mechanical characteristics improve with superplasticizer dosage up to 1.0 mass % and DAT up to 7.5 minutes, due to the improvement of superplasticizing effect, leading to increase the hydration of silicate phases (C3S and β-C2S) and formation of more CSH, CAH and CASH. These hydrates increase the gel/space ratio, modify the microstructure and consequently enhance the strength of cement paste. FTIR spectra are in a good agreement with those of chemical and physico–mechanical characteristics.

Benha University © 2023 Designed and developed by portal team - Benha University