Journal Article

Performance study of alkali-activated phosphate slag-granulated blast furnace slag composites: effect of the granulated blast furnace slag content

Zhang, Yannian, Yang, Daokui, Wang, Qingjie

2023

Overview

Alkali-activated materials (AAMs) are a kind of hardened slurry produced by an alkali activation reaction between a silicate precursor and an alkali activator that is treated as an environmentally friendly cementitious material that can be used in place of ordinary Portland cement (OPC). However, some studies point out that the AAMs with a single precursor had some defects. To realize the high value-added utilization of phosphorus slag (PS), this paper mixed PS with granulated blast furnace slag (GBFS) to prepare alkali-activated composite cementitious materials. The workability, mechanical properties, and hydration of alkali-activated phosphorus slag—granulated blast furnace slag (AAPG) were characterized using fluidity, setting time, compressive strength, flexural strength, hydration heat, XRD, FTIR, TG-DSC, and SEM + EDS. The results show that GBFS can improve the fluidity of AAPG, but the slurry will flash set after exceeding 20% GBFS content. GBFS can rapidly hydrate to generate C-S–H to improve its early strength, but the later stage results in larger pores due to the uneven distribution of matrix products. The hydration generation products of AAPG are C-S–H and C-(N)-A-S–H dominated by the Q 2 unit, with some hydrotalcite by-products generated.

• Publisher: Springer London,Springer Nature B.V
• Subject: Blast furnace slags / Cement / Civil Engineering / Compressive strength / Energy consumption / Engineering / Flexural strength / Granulation / Hardening furnaces / Hydration / Mechanical Engineering / Mechanical properties / Original Article / Particle size / Phosphorus / Portland cements / Precursors / Raw materials / Setting (hardening) / Slag / Slurries / Structural Materials / Workability