This experiment examined the effects of blending bottom ash produced after combusting dry livestock manure (BACL, 2-4 mm particle) as a soil amendment on the physicochemical properties of the root zone and growth response of creeping bentgrass in sandy soil. The treatments were designed as follows: control [100% sand], 3% BACL (3% BACL + 97% sand), 5% BACL (5% BACL + 95% sand), 7% BACL (7% BACL + 93% sand), and 10% BACL (10% BACL + 90% sand). Although BACL improved the soil physical properties, such as the capillary porosity, total porosity, and hydraulic conductivity, it reduced the cation exchangeable capacity. The BACL treatments increased the pH, EC, Av-P2O5, and Ex-K compared to the control. The turf color index, chlorophyll content, shoot length, clipping yield, and shoot dry weight after the BACL treatments were similar to the control. The growth and nutrient uptake of the roots in the BACL treatment were higher than those of the control. The BACL application amount was positively correlated with the capillary porosity and total porosity of the root zone (p <= 0.01) and with the growth and nutrient levels of the roots (p <= 0.05). These results suggest that applying BACL as a soil amendment enhanced the uptake of phosphorus and potassium in the roots of creeping bentgrass by improving the soil porosity in the root zone and by supplying phosphate and potassium.

Waste generation has been a source of environmental concern in case of inadequate management. However, the potential for resource recovery from waste has been highlighted, and circular economy strategies have been greatly promoted to achieve sustainability goals. Municipal solid waste incineration bottom ash (IBA) and mine tailings represent two relevant waste streams under study for geotechnical applications. The present work aims at investigating the physical, mechanical, chemical, and ecotoxicological characteristics of two mixtures of 90 % bottom ash and 10 % of two different mine tailings (one of iron and another of tungsten, tin, and copper) to evaluate their safe utilization. The results indicated that mixtures of IBA and mine tailings have good compressibility, permeability, and shear strength properties, comparable to granular soils. Additionally, adding 10 % mine tailings in the mixtures had minimal effect on the mechanical behaviour of IBA alone. No substantial concentration of potentially toxic metals or relevant ecotoxic effects were found in any of the analysed materials and their eluates. These results suggest that mixing IBA with mine tailings for geotechnical use, e.g., in embankments or road base/subbase may be a safe option. This represents a promising alternative for valorising both waste streams while promoting sustainable and circular solutions.

This research is the result of work on implementing a closed-loop economy in geotechnics, which aligns with the broader concept of a circular economy in construction by promoting the use of waste materials and reducing environmental impact. The research presented in the article focuses on the use of fluidized bed furnace bottom ashes, a by-product of coal combustion in fluidized bed boilers, in the production of cement-soil jet grouting slabs. Samples were analyzed for their structural and mechanical properties to assess their suitability for geotechnical applications. The mixtures were distinguished between those using CEM I and those using CEM II. Mixes based on two types of cements had an additional division based on the amount of additives: reference mix, 5% ash, 15% ash, and 10% ash + 5% microsilica. The conducted experiments aim to determine the physico-mechanical parameters of the new mixtures, highlighting the potential of these materials in mining and geotechnical technologies. The research took into account the impact of time over a period of two years for mortars and 28 days for cement-soil. The authors' studies included determining the compressive strength, bending strength, and imaging using computed tomography. Computed tomography allowed imaging of the internal structure and porosity analysis. Employing CEM II as the primary binding material slows early strength gain, but adding microsilica significantly enhances strength, compaction, and durability. Despite improved properties, CT imaging revealed increased cracking in mixtures with CEM II, indicating reduced water tightness and highlighting areas for further study.

The presence of expansive clay causes roads to undergo damage such as wavy, cracked, and even potholes. This type of soil shows that the soil is prone to swelling and shrinking. A base soil handling method against the effects of swelling and shrinking is chemical soil stabilization such as mixing the soil with lime, cement or additional materials. In this study, the stabilization method used was the fly ash and bottom ash geopolymerization reaction. Fly ash and bottom ash is an effective alternative to replace cement. Fly ash and bottom ash with addition of alkali activators of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) can serve as a binder similar to cement. This study aimed to improve the physical property and mechanical property tests of the soil such as bearing capacity and swelling potential as a requirement for subgrade. All physical property test results revealed that using fly ash-bottom ash geopolymer paste can improve qualities such as specific gravity, Atterberg limit, and grain size to improve expansive clay soil. Likewise, the mechanical property test results showed that the subgrade stabilized with fly ash-bottom ash geopolymer can increase its strength to surpass the requirements for road subgrades.

Bottom ash (BA) is a byproduct produced during coal combustion and can be utilized in mortar as a column material to conserve natural resources and promote sustainable ground stabilization. In this paper, the load-carrying capacity performance of the embankment resting on cement bottom ash columns (CBAC) improved ground was examined. Physical model tests and numerical analysis were conducted for the soft soil improved with three columns spacing to diameter ratios (s/d) of 1.8, 2.4, and 3.6 and two columns length to diameter ratios (L/d) of 6 and 8. Three earth pressure transducers, load cell, and pore water pressure transducer were employed to measure the applied vertical stress on the bottom and top of the column and surrounding clay, embankment surface, and excess pore water pressure (u '), respectively. The findings obtained from both physical and numerical models demonstrated that ultimate bearing capacity (qult) increased by reducing the s/d and increasing the L/d values. The qult increased by almost 1.15, 1.39, 1.70 times and 1.18, 1.44, and 1.77 times as compared to the unimproved soil for the s/d of 3.6, 2.4, and 1.8 with L/d values of 6 and 8, respectively. The maximum improvement was achieved for the model with CBAC having L/d of 8 and s/d of 1.8. In addition, a mathematical equation with R2 of 0.999 was established for the determination of the predicted qult. The results of this paper can lead to the usage of BA as a green material in the column for ground stabilization.

In cold and saline soil areas, concretes usually experience multi-factor erosions, such as freezing- thawing cycles (FTCs), drying-wetting cycles (D-Ws), and salt erosion. To promote green and sustainable development of the construction industry, municipal solid waste incinerator bottom ash (MSWIBA) was adopted as a partial replacement for conventional fine aggregates in concretes. In this study, the coupled effects of the D-Ws and salt erosion (i.e., 5 % NaCl solution and 5 % Na2SO4 2 SO 4 solution) were experimentally conducted to investigate the mechanical and micro- structural properties of ordinary and MSWIBA concretes. The results showed that D-Ws had a negative effect on the mechanical properties of concretes. The depth and width of cracks in concretes increased with the D-Ws raised. During the D-Ws, the influence of salt solution on concretes could be divided into two stages. Initially, the filling effect of salt crystals was beneficial to the development of concrete strength. Subsequently, salt crystals accumulated in concretes caused cracks, and accelerated the deterioration of concrete specimens. Meanwhile, sodium sulphate reacted with hydration products in concretes to produce some expansive substances, the evident diffraction peaks of expansive substances (e.g., gypsum and ettringite) had been clearly observed after D-Ws. Thus, the damage effect of 5 % Na2SO4 2 SO 4 solution (SS) to concrete structure was more serious than that of water (WT) and 5 % NaCl solution (CS). Furthermore, the total porosity of the concrete specimens generally decreased with the MSWIBA substitution rate increased. There was an optimal MSWIBA content for concretes to obtain the excellent mechanical and microstructural properties. In detail, when the substitution rate of MSWIBA was between 0 % and 33.0 %, it had an excellent effect on improving the pore structure of concretes. Specifically, the compressive strength of concretes was larger than 35.0 MPa when the substitution rate of MSWIBA with natural river sand was between 24.8 % and 57.8 %, whereas the substitution rate of MSWIBA should not exceed 33.0 % exposed to D-Ws. This study could provide a significant reference for the sustainable development of concretes in cold and saline soil areas, as well optimization and innovation usage of MSWIBA.

The rational disposal and resource utilization of municipal solid waste incineration bottom ash (MSWI-BA) is an urgent problem to be solved. This study explores the impact of MSWI-BA and its finely ground powder (MSWIBAP) as fine aggregates and solidifying agent components in pre-mixed fluidized solidified soil (PM-FSS) by conducting tests on the unconfined compressive strength and volume stability. Additionally, it analyzes the composition and microstructure properties of hydration products using techniques such as XRD, TG-DSC, MIP, and FTIR. The results demonstrated that the PM-FSS incorporating MSWI-BA and MSWI-BAP exhibited a dense microstructure and excellent mechanical properties, with the main hydration products being Aft, C-(A)-S-H gel, square crystal, etc. The volume deformation of PM-FSS with MSWI-BA and MSWI-BAP increased, but it did not affect the development of its mechanical strength. MSWI-BA can be used as a solidifying agent component and fine aggregate for the preparation of PM-FSS, achieving its resource utilization.

In tropical regions, heavy rainfall induces erosion and shallow landslides on road embankments. Cement-based stabilization methods, common in these regions, contribute to climate change due to their high carbon footprint. This study explored the potential application of coir fiber-reinforced laterite soil-bottom ash mixtures as embankment materials in the tropics. The objective is to enhance engineered embankment slopes' erosion resistance and stability while offering reuse options for industrial byproducts. This study examined various mix designs for unconfined compressive strength (UCS) and permeability, utilizing 30% bottom ash (BA) and 1% coir fiber (CF) with varying sizes ranging from 10 to 40 mm, 6% lime, and laterite soil (LS), followed by microstructural analyses. The results demonstrate that the compressive strength increases as the CF length increases to 25 mm. In contrast, permeability increases continuously with increasing CF length. Lime-treated mixtures exhibit superior short- and long-term strength and reduce permeability owing to the formation of cementitious materials, as confirmed by microstructural analyses. A lab-scale slope box was constructed to evaluate the surface erosion of the stabilized laterite soil embankment. Based on the rainfall simulation results, the LS-BA-CF mixtures show better resistance to erosion and deformation compared to untreated LS, especially when lime is added to the top layer. This study provides insights into a sustainable and cost-effective approach for slope stabilization using BA and CF, offering a promising solution for tropical regions susceptible to surface erosion and landslides.

The present study has focused on stabilizing the soils of the embankments and improving the mechanical properties of gravel in subbases of pavements with different contents of bottom ash from thermal power plants and low percentages of lime. The density, humidity, simple resistance strength and bearing capacity of the new materials resulting from this combination have been studied. The results indicated that the optimal proportion of bottom ash added to the analyzed soil is 15%, while the optimal addition of lime is 1% for application in embankments and 2% for application in road subgrades. In clay soil that has a low simple resistance strength when 25% of bottom ash is added without lime, it can double the resistance. In the case of the gravel evaluated, it was found that the optimal ratio between the addition of bottom ash and lime is 6.5. In conclusion, it can be noted that soil that does not have any resistance when certain percentages of bottom ash are added, its properties are improved to be used in embankments.