Title: Carbonation-Activated Steel Slag Binder as Alternative Cementing Material

Author(s): Yixin Shao, Mehrdad Mahoutian and Zaid Ghouleh

Publication: Symposium Paper

Volume: 320

Issue:

Appears on pages(s): 21.1-21.14

Keywords: steel slag, carbonation activation, strength, slag-bond wallboard, slag-bond block

DOI: 10.14359/51701059

Date: 8/1/2017

Abstract:
Steel slag is the by-product of steel making process. Because of its chemical composition and high temperature process, steel slag is carbon dioxide reactive. This property can be utilized to develop steel slag binder to replace portland cement in making precast building products. This paper summarizes a recent study on the carbonation activation of steel slag for binder application. Different types of steel slags are examined for their capacity to develop strength. The strength gain and carbon uptake are evaluated. It was found that BOF (basic oxygen furnace) and KOBM (Klockner oxygen blown maxhutte) slags are more carbon reactive than EAF (electric arc furnace) slag. The strength gain is attributed to the formation of calcium silicate-hydrates and calcium carbonates through the carbonation activation of calcium silicates. Two building products are successfully manufactured using activated slag as primary binder: slag-bond wallboards and slag-bond blocks. The slag-bond products consume zero natural resources, recycles industry wastes, sequester carbon dioxide and can be made carbon negative.