Work

Study on the bonding performance and micromechanism between alkali-activated mortar and rock

Year: 2026

Type: article

Abstract: Alkali-activated mortar (AAM) has emerged as a sustainable alternative to ordinary Portland cement (OPC) for rock-based applications, yet its bonding behavior with rock remains underexplored. This study investigates the interfacial performance between AAM and sandstone through orthogonal experiments, Brazilian splitting tests, and microstructural analyses (SEM-EDS, XRD). Results show that binder formulation and mortar composition significantly affect bond strength: slag content dominates early-age bonding, while the binder-to-sand ratio controls long-term strength. The optimal mixture (80% slag, water-to-binder ratio 0.35, binder-to-sand ratio 1.5) achieved a 28-day bond strength of 2.67 MPa, surpassing the sandstone’s tensile strength (2.42 MPa). Failure mode shifted from interfacial debonding to cohesive fracture within sandstone, accompanied by a wider interfacial transition zone (ITZ), indicating enhanced physicochemical integration. These findings improve the scientific understanding of the bonding mechanism between AAM and rock and may provide useful implications for rock engineering applications.

Source: Scientific Reports

DOI: 10.1038/s41598-026-48531-1

Authors: Tianzuo Wang, Xuan Xu, Fei Xue, Xin Zhang, Peifeng Cheng, Huijun Kang

Institutions: Shaoxing University, Northeast Forestry University

Language: English

Topic: Concrete and Cement Materials Research

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,690

Funder: National Natural Science Foundation of China