Manufacturing and Properties of Alkali-Activated Weld-Slag Binders

Weld slag can be utilized as the raw material in the production of alkaliactivated binder for the replacement of Portland cement to reduce energy cost and carbon dioxide emission. In the study, weld slags were first ground and then mixed with different amounts of waste glass powders and various activators to make alkali-activated weld-slag binders under a high temperature manufacturing process. By conducting a series of tests, the effects of weld-slag replacement percentage, alkaline equivalent content and water/binder ratio of activator, fineness of weld-slag powders and curing temperature on the volumetric expansion and compressive strength of alkali-activated weld-slag binders were evaluated. As a result, the optimal mixing process, mixture design and curing temperature for making the specimens with volumetric stability and high compressive strength were proposed. It is found that the compressive strength of the alkali-activated weld-slag binders made under the optimal conditions can reach up to 49 MPa. Hence, the alkali-activated weld-slag binder can replace Portland cement paste as a novel construction material. © 2022, Chinese Institute of Civil and Hydraulic Engineering. All right reserved.