The Influence of Natural Pozzolans Structure on Marl Soil Stabilization

Abstract

Marl as a calcareous soil has heterogeneous nature in terms of structure and properties. Any change in the water content of marl can cause significant strength loss; therefore, prior stabilization while constructing civil infrastructures is necessary. A fundamental element in soil stabilization is the relationship between soil structure and stabilizers, but this important factor has been ignored in the available literature, especially in the case of marl soil. Lately, alternative environmentally friendly additives (natural pozzolans) as well as traditional chemical stabilizers (cement and lime) have been successfully used for stabilization of marl soil. This paper presents the results of an experimental study which investigates the influence of natural pozzolans structure on marl soil stabilization. Transmission electron microscopy (TEM), X-ray fluorescence (XRF), and Fourier transform infrared spectroscopy (FTIR) tests were used for size and structure analysis of marl soil and two types of natural pozzolans called Qizkorpi and Mamaloo of Iran which have been successfully used for marl soil stabilization by the authors, recently. Based on the obtained results by TEM, FTIR, and XRF tests, due to the similarity of the structure and size of Gizkorpi volcanic ash and marl soil when compared to that of Mamaloo volcanic ash, it can be concluded that the electrostatic and magnetic interactions in marl and Gizkorpi volcanic ash lead to a better stabilization and strengthen of the marl, while these interactions are less in Mamaloo volcanic ash when mixed with the marl soil.