Valorization of converter steel slag into eco-friendly ultra-high performance concrete by ambient CO2 pre-treatment

Gang Liu, Katrin Schollbach, Peipeng Li (Corresponding author), H.J.H. Brouwers

Research output: Contribution to journalArticleAcademicpeer-review

59 Citations (Scopus)
143 Downloads (Pure)

Abstract

The converter steel slag is a by-product during the steel-making process, which usually acts as an inert ingredient in construction due to the relatively low reactivity. However, its mineral composition results in a high reactivity in a CO2 rich environment. This study reveals the modification of converter steel slag by an ambient CO2 pretreatment, and the application of modified converter steel slag as the supplementary cementitious material (SCM) in the design of eco-friendly ultra-high performance concrete (UHPC) by using a particle packing model. The results show that converter steel slag after ambient CO2 pretreatment is feasible to be used in eco-friendly UHPC design, which achieves a relative higher compressive strength over 150 MPa with the cement substitution from 15% to 45%, compared to non-carbonated steel slag. The ambient CO2 pretreatment can modify the physical and chemical properties of converter steel slag particles, which produces a rough and porous surface of slag particles because of the precipitation of calcium carbonate and amorphous silica gel as carbonation products. Consequently, the incorporation of carbonated steel slag improves the cement hydration, enhance the formation of ettringite and C-S-H, while densify the microstructure compared to non-carbonated slag in eco-friendly UHPCs. The leaching of potentially hazardous elements, e.g. Cr and V from carbonated steel slag can be efficiently reduced below legal limits in UHPC mixtures.

Original languageEnglish
Article number122580
Number of pages11
JournalConstruction and Building Materials
Volume280
DOIs
Publication statusPublished - 19 Apr 2021

Bibliographical note

Funding Information:
This research was supported by the funding of China Scholarship Council (No. 201606300062) and Eindhoven University of Technology. Furthermore, the authors wish to express their gratitude to Tata Steel, IJmuiden, Netherlands for the supporting of raw materials and XRD.

Keywords

  • Ambient carbonation
  • Converter steel slag
  • Pozzolanic reaction
  • Recycling
  • Ultra-high performance concrete

Fingerprint

Dive into the research topics of 'Valorization of converter steel slag into eco-friendly ultra-high performance concrete by ambient CO2 pre-treatment'. Together they form a unique fingerprint.

Cite this