Enhancing soft subgrade soil with a sewage sludge ash/cement mixture and nano-silicon dioxide

Zhou

et al. 2021

Sustainability

In order to explore the modification effect of carbonization time on nano-MgO-modified cement soil, unconfined compressive strength tests of nano-MgO-modified cement soil with carbonization times of 0 h, 6 h, 1 d, 2 d and 4 d were carried out. A method for normalizing the stress–strain curve was proposed, and the influence of nano-MgO content and carbonization time was investigated from the three aspects of compressive strength, peak strain and energy dissipation. The test results show the following: (1) The compressive strength of the modified cement soil can be significantly improved by adding 1.0% nano-MgO and after 1 d carbonization. (2) Under the same nano-MgO content, the peak strain of the modified cement soil after 2 d carbonization reaches the maximum, which can significantly increase its ductility. However, the nano-MgO content has little influence on the peak strain of the modified cement soil. (3) Under the same nano-MgO content, the energy dissipation rate of the modified cement soil after 1 d carbonization reaches the maximum, which can better resist the damage of external load.

Section: Introductionmentioning

confidence: 99%

Influence of Carbonization Process on the Mechanical Properties of Nano-MgO Modified Cement Soil

Zhou

et al. 2021

Sustainability

“…e country's municipal sewage sludge output is expected to exceed 60 million tons by 2020. e huge amount of sludge will cause substantial environmental problems [1][2][3], and thus, sludge stock absorption through various disposal methods should be urgently considered. e municipal sludge is o en solidi ed with materials and then used as land ll cover materials [4,5], subgrade llers [6], garden soil [7], and brick-making materials [8] or land lled [9].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of Moisture Content Effect on Geotechnical Properties of Solidified Municipal Sludge

Chen

Advances in Polymer Technology

et al. 2020

Moisture content is an important factor affecting the geotechnical properties of solidified municipal sludge (MMS). Typical municipal sludge in China was chosen to investigate the effects of initial moisture content (defined as w0) on geotechnical properties of MMS solidified by self-developed CERSM solidifying agent. In addition, the microstructure changes of solidified sludge samples in this study were explored with scanning electron microscopy and mercury intrusion porosimetry. Mechanical experiment results showed that the unconfined compressive strength, cohesion, and internal friction angle of the MMS increased with the decrease in initial moisture content, but the permeability coefficient changed oppositely. The permeability coefficient of solidified sludge samples was between 10−8 and 10−10 cm/s. But after the drying-saturated process, the permeability coefficient of MMS can be increased up to 4 times, mainly due to the formation of a considerable number of microconnected pores and microcracks in the process of drying. The research results are of great significance to the safe disposal and utilization of municipal sewage sludge in China.

“…At present, soil stabilizers rapidly solidifying soil are those mainly used in the treatment of building foundation, highway sub-grade reinforcement, water conservancy engineering such as slope solidification, canal seepage prevention and so on [4][5][6][7][8][9][10][11] . Their task mainly aims at solidifying soil as long as possible, better for permanent, i.e.…”

mentioning

confidence: 99%

“…Their task mainly aims at solidifying soil as long as possible, better for permanent, i.e. unidirectional solidification without further collapse [4][5][6][7][8][9][10][11][12][13][14] . Furthermore, the inorganic soil solidifying agents have a seriously negative effect on the soil.…”

mentioning

confidence: 99%

“…The solidified soil layer basically loses the ability for plant growth, and its alkaline substance rinsed into the land is harmful to the vegetation. At the same time, the treatment of abandoned solidified soil is also difficult [7][8][9][10][11][12][13][14] . It is clear that the soil stabilizer used in construction can't be used for the consolidation of seedling soil.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Study on a new type of environment-friendly polymer and its preliminary application as soil consolidation agent during tree transplanting

Wei

Yang

et al. 2021

Sci Rep

Transplanting trees with rhizospheric soil is an important way to facilitate tree survival in the process of landscaping and reforestation. Traditional way to prevent looseness of rhizospheric soil is forming soil balls around the roots with bags, boxes or rope wrapping, which is cumbersome, laborious and easy to break. This study is aimed to develop a new type of degradable environment-friendly polymer as soil consolidation agent to facilitate tree transplanting. In this paper, the KGM/CA/PVA ternary blending soil consolidation agent was prepared by using Konjac glucomannan (KGM), chitosan (CA) and polyvinyl alcohol (PVA) as raw materials. Through the verification and evaluation, the clay and sandy soil can be consolidated and formed into soil balls by the ternary blend adhesive, which was convenient for transportation. The preliminary application of the ternary blend adhesive in the transplanting process of sierra salvia, Japanese Spindle (Euonymus japonicus) and Juniperus sabina ‘Tamaricifolia’ confirmed that the application of soil consolidation agent can effectively solve the problem that the root ball of seedling is easily broken in the process of transplant. And the application of soil consolidation agent has no adverse effect on the growth of transplanted seedlings. The research and development of ternary blending soil consolidation agent and its preliminary application in seedling transplanting will provide a new solution to solve the problem of soil ball breakage in the process of seedling transplanting. This is an important stage in the development of new seedling transplanting technology. Therefore, the research and development of soil consolidation agent is of great significance.