# Lime–Ground Glass–Sodium Hydroxide as an Enhanced Sustainable Binder Stabilizing Silica Sand | Journal of Geotechnical and Geoenvironmental Engineering

Abstract

Ordinary portland cement (OPC) has been extensively used for decades to improve the engineering properties of a variety of soils. However, the environmental issues related to the production of OPC have created an urgent need to develop and use alternative binders such as alkali-activated cements (AAC). Thus, this work assesses the mechanical performance of a sandy soil amended with an AAC composed of ground waste glass (GWG), carbide lime (CL), and sodium hydroxide (NaOH). The effect of key factors, such as the presence of a NaOH solution, the dry unit weight, and the amount of binder were evaluated on the unconfined compressive strength (

$qu$

), initial shear modulus (

$G0$

), and accumulated loss of mass (ALM) of compacted sand-binder specimens cured for 7 days. When analyzing the curves that correlated the mechanical behavior of the blends (

$qu$

,

$G0$

, and ALM) with the

$η/Biv$

index, the results show that the alkaline solution has a significant positive influence on the mechanical response of the tested specimens. The improved mechanical performance of the alkali-activated treatments was associated with the formation of a blend of C─ S─ H and (C,N)─ S─ H cementitious compounds coexisting in the same cementitious matrix (alkaline hybrid cement), of heterogeneous structure and composition, and characterized by developing in greater quantity than those produced from a pozzolanic reaction.