Multi-scale analysis on soil improved by alkali activated binders

Enza Vitale,Giacomo Russo,Dimitri Deneele,A Tarantino,E Ibraim

doi:10.1051/e3sconf/20199211003

Abstract

In the present paper, the use of alkali activated binders to improve engineering properties of clayey soils is presented as an alternative to traditional binders such as lime or cement. An alkali-activated fly ash and its chemo-physical evolution has been monitored at increasing curing times by means of X-Ray Diffraction and Scanning Electron Microscopy. Alkali-activated binder has been mixed with soil for evaluating the improvement of its mechanical behaviour. One-dimensional compression tests on treated samples have been performed with particular reference to effects induced by binder content and curing time. Test results showed a high initial reactivity of the alkali activated systems promoting formation of new mineralogical phases responsible of the mechanical improvement of the treated soil.

Highlights

The development and the use of environmentally friendly binders as an alternative solution to traditional binders such as lime or cement in a low carbon agenda is of prime importance in the construction sector
Rios et al [7] compared the mechanical behaviour of samples of sand improved by an alkali activated fly ash binder and the similar samples improved by cement, highlighting the effectiveness of the alkali activated binders in increasing the shear strength properties of the soil
An insight into the mechanical improvement induced by an alkali-activated binder based on the activation of a fly ash on a clayey soil has been presented

Summary

Introduction

The development and the use of environmentally friendly binders as an alternative solution to traditional binders such as lime or cement in a low carbon agenda is of prime importance in the construction sector. The use of novel and efficient binders for geotechnical applications is a promising issue in terms of sustainability since it reduces the carbon footprint and allows reusing secondary by-products such as artificial pozzolans. These by-products can be involved in soil improvement as cementing agents if properly activated, inducing a mechanical improvement of natural soils, not suitable for construction purposes. Rios et al [7] compared the mechanical behaviour of samples of sand improved by an alkali activated fly ash binder and the similar samples improved by cement, highlighting the effectiveness of the alkali activated binders in increasing the shear strength properties of the soil. The effects of binder content and curing time on the mechanical performance of treated samples have been considered

Material

X-Ray diffraction analysis

One-dimensional compression tests

Results

Findings

Conclusions