Microstructural $$\eta$$: chemical–mechanical bridge for anchorage design in alkali–activated concretes

Abstract The anchor design for Low-Carbon Concretes still lacks parameters that link microchemistry to structural performance. This work introduces a microstructural coefficient $$\eta$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>η</mml:mi> </mml:math> , defined from gel density and interfacial porosity of the N-A - S-H / C - A - S-H networks, to extend the classical Tepfers. The analytical derivation shows that $$\eta$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/Mat