Stabilization of Clay Powder With Mineral Wool Fly Ash

Abstract

The aim of this article – to determine short term and long term strengthening of clay soil, by strengthening it with fly ash obtained during the production of mineral wool. This article introduces research which is used to determine the optimal ratio of fly ash in cement suspension for strengthening of clay soil. Samples which were investigated in this research work prepared by mixing Portland cement, mineral wool fly ash, clay powder, sand and water. All investigated samples compressive strength after 6 months exceeded 1.7 MPa. It is enough of such strength in geotechnics to conduct strengthening of soil and it is possible to argue that soil is strengthened.

The Effects of Mineral Wool Fly Ash on Cohesive Soil Strength Behaviour

“…This research represents fly ash as a stabiliser for cohesive soil with the results after 1.5 years compared to previous research (Zakarka et al, 2019) after 7-183 days. Obtained results allow gaining understanding about strength increment of stabilised clay with fly ash in 1.5 years.…”

“…-Portland cement (C) CEM I 42.5 R, which complies with the LST EN 197-1:2011/P:2013 Cement -Part 1: Composition, specifications and conformity criteria for common cements; fly ash (FA) obtained from a mineral wool factory in Vilnius (Lithuania) as mineral wool production waste, the chemical composition of which is presented in Table 1; sand, which granulometric composition is presented in Figure 1, was also used in previous research (Zakarka et al, 2019); clay powder (CP), which chemical composition is presented in 2019), investigated sand is assigned to uniform sand (SaU). For investigated sand and clay mixtures, plastic (W p ) and liquid (W L ) limits were determined without fly ash additives, as Trivedi et al (2013) recommended.…”

“…Fly ash also improves strength characteristics of soils, stabilises bases or subgrades, stabilises backfill, reduces lateral earth pressures, and stabilises embankments to improve slope stability. Fly ash is also used as an expansive soil stabiliser (Jalal et al, 2020;Sharman & Sivapullaiah, 2016), curing agent for man-made contaminated soil (Li et al, 2018), organic soil stabiliser (Nath et al, 2017), cohesive or non-cohesive soil stabiliser (Binal, 2016;Simatupang et al, 2020;Zakarka et al, 2019), or for other purposes (Elahi et al, 2020;Khajeh et al 2020;Luo et al, 2018;Phummiphan et al, 2016).…”

“…Also, the chemical composition of fly ash varies (Bhatt et al, 2019;Kang et al, 2020) and depends on industry type and provided products (Cho et al, 2019). Fly ash collected during the production of mineral wool gain an advantage due to its constant and more predictable composition (Zakarka et al, 2019). Diversity of the chemical composition of fly ash allows studying the possibilities for reusing local fly ash and makes it possible to achieve different soil strengths and increments of stiffness (Deepak et al, 2020).…”

“…Most often, compression tests of the soil stabilised with fly ash are performed after 2-7 days (Graytee et al, 2018), or after 1-2 weeks (Liang et al, 2020), or after up to 1-2 months (Gu & Chen, 2020;Liang et al, 2020). There is little information in the literature on the results of the tests of stabilised soil after 2-6 months (Chousidis et al, 2016;Jia et al, 2020;Wong, 2015;Yoobanpot et al, 2017;Zakarka et al, 2019) or even after 1-2 years (Giergiczny, 2019;Moon et al, 2016).…”