Strength, Stiffness, and Microstructure of Wood-Ash Stabilized Marine Clay

Abstract

The world’s population is growing at a rapid pace, thus increasing the need for shelter, which, because of increased carbon emissions, is making our planet less habitable. Thus, supplementary cementitious materials (SCMs) are used to reduce the embodied carbon emissions in the building sector. Wood-ash, as a replacement for cement in ground improvement, seems to be a promising material. In this study, we considered the strength, stiffness, and microstructural behavior of marine deposited clays of Cyprus treated with cement and wood-ash as a cement replacement. Since clay is abundant in nature, it could help stabilize waste to improve the mechanical behavior of produced composites. Portland cement (7%, 10%, and 13%) was replaced with various amount of wood-ash (5% and 10%) with two different dry densities (1400 and 1600 kg/m3) and three distinct curing periods (7, 28, and 60 days). Unconfined compressive strength (UCS), direct shear, porosity and pulse velocity tests were performed. Additionally, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy analysis (EDX) were performed for microstructural evaluation of clay–wood-ash–cement mixtures. The results revealed that the replacement of cement with 5% of wood-ash yielded superior performance. The microstructure investigation of wood-ash–cement–clay blends further showed the formation of a densified matrix with stable bonds. Furthermore, the porosity and strength properties (unconfined compressive strength, splitting tensile strength, cohesion (C) and friction angle (ϕ)) of blends have unique relationships with porosity and binder contents, which were further confirmed by other supplementary materials and soils.

Improvement of geotechnical properties of clayey soil with saw dust ash stabilization

“…Typical XRD pattern wood ash [7] Fig. 4 illustrate SEM analysis of SDA as angular, brittle, and elongated granules with jagged edges of SDA from [11]. 4 Saw dust ash application Some research for applications of SDA utilization in road construction has been conducted in few past years.…”

“…The industrial output of a wood manufacturing plant produces a variety of by-products. One of the majors is saw dust ash, produced when residue from wood chips, bark, sawdust, and cuts is used as an energy source [11]. The yearly production of saw dust ash is around 10,000 tons, but with increased production, the amount is approximately double.…”

Influence of Wood Fly Ash on Concrete Properties through Filling Effect Mechanism

“…The use of coal or biomass fly ash in concrete reduces the consumption of natural resources and reduces the CO 2 emissions caused primarily through the reduction of Portland cement content in concrete [ 19 ]. Besides in the concrete industry, it has been shown that fly ash finds its application in various construction areas [ 20 , 21 , 22 , 23 , 24 , 25 ]. Pulverized coal fly ash has gained considerable importance as a supplementary cementitious material due to its pozzolanic properties, but also due to the improved workability of concrete attributed to the spherical shape and plain surface of ash particles.…”

Solidification Effect and Mechanism of Marine Muck Treated with Ionic Soil Stabilizer and Cement

“…However, because of the properties of high moisture content, high porosity and low strength in natural state of soft soil, it cannot be used directly as subgrade or foundation and is difficult to be recycled as building materials [1][2][3]. Adding suitable binders into soft soil is considered to be a very useful way to solve the above significant engineering problems and has been widely used [4][5][6][7].…”