Evaluation of NaOH Activated, Ambient Cured Slag as a Binder to Produce a Building Material

Nastassia Thandiwe Sithole, Joseph Makela Nseke

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review


The worldwide supply constraints and the anticipated high demand for sodium silicate as well as environmental issues associated with the use of sodium silicate has given dawn to the need to opt for alternative activating solutions such as alkali-hydroxides. The current study mainly focuses on the evaluation of mechanical and chemical properties of Granulated Blast Furnace Slag (GGBFS) Binder-Spend Foundry Sand (SFS) based material toward the development of a durable material for building applications. Activated GGBFS was synthesized using a NaOH solution as the sole GGBFS activator. Uniaxial compressive strength (UCS) tests were conducted on the GGBFS-SFS based specimens to investigate the influence of varying amount of GGBFS binder (15 %-45 %) cured at 80o C. Results showed that the specimen consisting of 45% GGBFS and 55% SFS at a solid to liquid of 0.17 yielded the high UCS equivalent to 11.07MPa. Increase in UCS has been attributed to the presence of calcium silicate hydrate phase confirmed by XRD analysis. In conclusion, GGBFS-based binder waste foundry-based material sand can be considered as a promising and efficacious building material as per ASTM C34-13, C129-14a and South African standard (SANS227: 2007).

Original languageEnglish
Title of host publicationKey Engineering Materials
PublisherTrans Tech Publications Ltd
Number of pages8
Publication statusPublished - 2022

Publication series

NameKey Engineering Materials
ISSN (Print)1013-9826
ISSN (Electronic)1662-9795


  • alkali activated slag
  • alkaline activators
  • geopolymer
  • granulated furnace slag
  • Microstructure
  • unconfined compressive strength

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'Evaluation of NaOH Activated, Ambient Cured Slag as a Binder to Produce a Building Material'. Together they form a unique fingerprint.

Cite this