Effects of biochar particle size and dosage on the desiccation cracking behavior of a silty clay

Lu, Yu; Gu, Kai; Shen, Zhengtao; Wang, Xiang; Zhang, Yuping; Tang, Chaosheng; Shi, Bin

doi:10.1016/j.scitotenv.2022.155788

Cited by 19 publications

(13 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Then biochar was air-dried at 40°C for 48 h and crushed. Based on the previous research studies, we selected fine-grain biochar (fine: <0.25 mm, coarse: 0.25 mm < size <2 mm) for our experiment ( 9 – 11 ). Therefore the crushed biochar was sieved through a 0.25 mm (No.…”

Section: Methodsmentioning

confidence: 99%

“…Based on the previous research, biochar mass proportions of 0%, 5%, 10%, and 15% (w/w) were selected for this experiment ( 8 , 9 , 11 ). First, the soil was collected into a plastic container, and the measured amount of biochar was added to the container and mixed well.…”

Section: Methodsmentioning

confidence: 99%

“…Adding biochar to soil has been considered in various situations, including soil fertility ( 3 , 4 ), remediation of contaminated soils ( 5 ), soil carbon sequestration ( 6 ), and improving soil’s physical and chemical properties ( 7 ). Further, several studies have focused on the effect of biochar on the cracking behavior of silty–clayey soils under desiccation and wetting–drying cycles ( 8 – 12 ). However, among the various biochar applications, little attention has been given to engineering applications, and no research has been undertaken on the impact of the freeze–thaw cycle on surface crack development.…”

mentioning

confidence: 99%

“…Over the last few years, many studies have been conducted on soil biochar amendment to minimize desiccation cracks ( 8 , 9 , 11 , 18, 19 ). According to Lu et al, biochar lowers desiccation cracks by decreasing tensile stress on the soil surface, increasing repulsive forces between soil particles, occupying the shrinking space between soil particles, and decreasing tensile strength between soil particles ( 11 ).…”

mentioning

confidence: 99%

“…Further, they explain that biochar’s influence is not limited to the final crack pattern but influences the whole process during water evaporation and crack development. Furthermore, Lu et al investigated the effect of biochar particle size and dose on the desiccation cracking properties of silty clay and discovered that using 10% biochar with fine particle size had the highest performance in preventing soil cracking ( 9 ). Therefore, as the previous studies are limited to biochar’s impact on desiccation cracking and wetting and drying cycles on crack propagation, we explored the freeze–thaw cycle of surface crack formation under different biochar dosages.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Evaluation of Cracking in Biochar-Amended Clayey Soil Under Freeze–Thaw Cycles

Hewage

Roksana

Tang

et al. 2023

Transportation Research Record: Journal of the Transportation R

View full text Add to dashboard Cite

Biochar has been identified as an efficient soil amendment, and it shows promising results in inhibiting desiccation cracks. However, the effects of biochar on soil freeze–thaw cycle behavior on surface cracking have not been considered. This study focuses on the influence of wood biochar dosages on surface cracking under freeze–thaw cycles on clayey soils, and the mechanism was investigated through image analysis and water evaporation. Samples were prepared with different biochar dosages of 0%, 5%, 10%, and 15%, and maintained for 12 h constant temperature freeze (−20°C) and thaw (21°C) cycles. Every 12 h, sample weight, 2D images, and 3D scans were taken. Also, a parallel desiccation experiment was conducted at room temperature for comparison purposes. Results show that with an increased dosage of biochar for the freeze–thaw samples, the crack ratio, fractal dimension, total crack length, and average crack width decrease. Also, the crack propagation rate decreased with the increased amount of biochar. Further, the water evaporation rate decreased with increasing biochar for the freeze–thaw samples; the reasons can be correlated with the reduced thermal conductivity of soil with added biochar, and the reduction in bulk density causing reduced thermal conductivity. Results indicate that the final crack patterns are associated with the initial ice crystal patterns. Samples with low biochar produced larger-sized parallel layered texture ice crystals, and increased biochar content caused homogeneous massive ice crystal texture; these responses can be correlated with changes in soil hydraulic conductivity.

show abstract

Section: Methodsmentioning

confidence: 99%