Recycling of waste crushed stone powder for alkali-activated material production

The growing use of crushed stone and manufactured sand poses a major challenge to the recycling of their by-product known as crushed stone powder (CSP). To establish an effective recycling method for CSP, the authors conducted a detailed investigation on the setting, strength, and durability of alkali-activated materials (AAMs) with slag (GGBFS) and CSP as precursors, and examined their chemical and microstructural characteristics by X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis. Experimental results clarified in detail the performance features and influencing factors of AAM made from a blend of CSP and slag, and indicated that CSP can be utilized as an inactive precursor in a large blending ratio (50-80%) to produce AAMs with high strength and excellent durability. The GGBFS/CSP-based AAMs have high flexural strength, reaching up to 1/5 similar to 1/6 of the compressive strength, surpassing 15.0 MPa. The AAMs using CSP almost retain the crystals from CSP within them, and the presence of CSP particles fragments C-A-S-H gels of polymerization reaction product, making them granular and discontinuous. Compared to the siliceous CSP, the limestone CSP slightly enhanced the strength properties of AAM.

Journal

JOURNAL OF MATERIAL CYCLES AND WASTE MANAGEMENT

Year

2024

Volume

26

Issue

4

Pages

2413-2434

ISSN

1438-4957

eISSN

1611-8227

DOI

10.1007/s10163-024-01973-z

WoS UID

WOS:001236069900002