Unconfined compressive strength characteristic of soft soil mixed with lime and nano alumina

2021 ◽  
Author(s):  
Ramez A. Al-Mansob ◽  
Wei Fua Wong ◽  
Jamal M. A. Alsharef ◽  
Taha M. Jassam ◽  
Jing Lin Ng ◽  
...  
2018 ◽  
Vol 53 ◽  
pp. 04021
Author(s):  
SHAO Yong ◽  
LIU Xiao-li ◽  
ZHU Jin-jun

Industrial alkali slag is the discharge waste in the process of alkali production. About one million tons of alkali slag is discharged in China in one year. It is a burden on the environment, whether it is directly stacked or discharged into the sea. If we can realize the use of resources, it is a multi-pronged move, so alkali slag is used to improve solidified marine soft soil in this paper. The test results show that the alkali residue can effectively improve the engineering properties of marine soft soil. Among them, the unconfined compressive strength and compressive modulus are increased by about 10 times, and the void ratio and plasticity index can all reach the level of general clay. It shows that alkali slag has the potential to improve marine soft soil and can be popularized in engineering.


2015 ◽  
Vol 77 (11) ◽  
Author(s):  
Fauziah Kasim ◽  
Aminaton Marto ◽  
Nur Amalina Abdul Rahman ◽  
Choy Soon Tan

This study presents the Unconfined Compressive Strength (UCS) and microstructure of clay soil stabilized with locally made Biomass Silica (BS) in the form of SH-85. Since the construction of highway on soft soil raises many problems due to its low strength, understanding about the basic characteristics of soft clay and mixed with BS, play important role for improving the strength of the soft clay. The study carried out had the specific objectives to determine engineering properties of soft clay, to investigate the UCS of soft clay treated with BS and to analyze microstructure of the soft soil treated by BS with respect to various curing periods. In this study, 30 samples of clay soil were prepared under various curing periods (0, 7, 14 and 28 days) and mixed with BS at various percentages (5 %, 7 % and 9 %). The test results show that BS can increase the strength of the clay soil. The 9% BS treated sample for 7 days curing time achieved UCS of 710 kPa. This was approximately 6 times greater than that of untreated soil strength. The highest strength was 1216 kPa at 28 days curing for soil mixed with 9% BS. The images of Scanning Electron Microscopic show that the voids of the clay would filled by the new component resulted by the reaction of BS stabilizer with the natural clay samples. This led to a continuous soil fabric resulting with stronger and denser soil.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Son Bui Truong ◽  
Nu Nguyen Thi ◽  
Duong Nguyen Thanh

Soft soil is widely distributed in Vietnam, especially in the coastal area. In engineering practice, soft soil cannot be used to build any construction and needs to be improved or treated before building construction. In addition, Vietnam has many pig-iron or thermal power plants, which annually produce a huge amount of granulated blast furnace slag (GBFS). Thus, the use of this material for soft soil improvement needs to be considered. This paper presents experimental results on the unconfined compressive strength (UCS) of three Vietnam’s soft soils treated with Portland cement and Portland cement with ground granulated blast furnace slag (GGBFS). Binder dosage used in this study is 250, 300, and 350 kg/m3 with the three different water/cement ratios of 0.8, 0.9, and 1.0, respectively. The research results showed that the UCS of soil-cement mixtures depends on soil type, water/cement ratio, cement type, and binder content. Accordingly, the unconfined compressive strength increased with the increase of binder contents, the decrease of the natural water content of soft soil, water/cement ratios, and clay content. The highest value of UCS of treated soils was found for the soil at Site II with the Portland cement content, cement GGBFS, and water/cement ratio of 873 kg/m3, 2355 kg/m3, and 0.8, respectively. Besides, for all the three soils and two binder types, the water/cement ratio of 0.8 was found to be suitable to reach the highest UCS values of treated soil. The research results also showed that the UCS of treated soil with cement GGBFS was higher than that of treated soil with Portland cement. This indicated the effectiveness of the use of Portland cement with GGBFS in soft soil improvement. There is great potential for reducing the environmental problems regarding the waste materials from pig-iron plants in Vietnam and the construction cost as well.


Author(s):  
Songyu Liu ◽  
Roman D. Hryciw

Dry jet mixing has been widely used since the 1980s for stabilization of soft soil. The quality and strength of the dry-jet-mixed columns must be evaluated to confirm the success of the stabilization. The standard penetration test (SPT) is shown to be a simple and effective method for this task. The strength characteristics along the length of the column were determined, and correlations between the SPT blow count and the unconfined compressive strength were developed.


Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 302
Author(s):  
Yaxu Liu ◽  
Zhuang Liu ◽  
Erwin Oh ◽  
Dominic Ek Leong Ong

The study of the strength of reconstituted and stabilised soft soils is very important in geotechnical engineering. The soil particles, such as clay, sand, and silt play important roles in determining the behaviour of soils. The behaviour of clay and sand particles are unique; however, the behaviour of silt particles lie in a transitional form between sand and clay. Therefore, this paper seeks to investigate (a) the effect of silt contents on the strength of soft soils; (b) the effect of silt content on the strength of cement-stabilised soft soils; and (c) the microstructure of the soft soil specimens stabilised by cement with varying particle size distribution. A series of tests consisting in consolidated, isotropic undrained (CIU) triaxial tests, unconfined compressive strength (UCS) tests, and scanning electron microscope (SEM) images were conducted in this study to achieve these objectives. In conclusion, the relationship between the silt content and critical state behaviour of soft soils (both clay and silt particles) are proposed. For the cement-stabilised specimens, the unconfined compressive strength increases with the increase in silt content when the cement content is 10%. However, the UCS decreases with the increase in silt content when cement content is 30%. With cement content ranging from 15–25%, the UCS increases at first with the increase of silt content but decreases once the silt content reaches a ‘saturation’ point.


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 826 ◽  
Author(s):  
Jiansheng Shen ◽  
Yidong Xu ◽  
Jian Chen ◽  
Yao Wang

The use of desulfurization gypsum and steel/furnace slag composite cementitious material (DGSC) to solidify soft soil can fully utilize industrial wastes, reduce cement use and protect natural resources. By studying the unconfined compressive strengths of DGSC-solidified soil with different mix ratios, water-binder ratios and curing periods, the influence of those factors on the unconfined compressive strength of the soil can be analyzed. Furthermore, the quasi-water-cement ratio is introduced to predict the strength of the DGSC-solidified soil. The results show that the higher the DGSC content is, the better its effect on the soft soil. The variation in the unconfined compressive strength of DGSC-solidified soil overtime can be described by the same trend as that of cement-solidified soil but its early strength is lower than that of cement-solidified soil. When the water-binder ratio of the DGSC-solidified soil is the same as that of the cement-solidified soil, after a28-day curing period, the content of DGSC is higher than that of the 5% cement content, so the DGSC solidification effect is comparable to that of cement. Therefore, using DGSC instead of cement as a soft soil solidifying agent can meet the strength requirements of solidified soil.


2014 ◽  
Vol 936 ◽  
pp. 1382-1386
Author(s):  
Guo Cai Wang ◽  
Lin Chun Yu ◽  
Ling Sha

In order to study the inorganic composite curing agents of lime, gypsum, fly ash on the strength properties of EPS lightweight soil using recycled sludge, the unconfined compressive strength test and scanning electron microscope test are done to investigate the strength properties of EPS lightweight soil. The effect and scope of each curing agent is investigated and determined by means of single-doped unconfined compressive strength test, and the optimum proportion of the curing agent is further determined by the method of orthogonal unconfined compressive strength test, of which the stabilized effectiveness of the lightweight soil is compared with those only using cement as curing agent. Finally, the SEM test is done to study the microstructure and pore characteristics of the lightweight soil mixed with EPS adding with or without curing agent. The test results and curing agent can be used as conference when stabilizing soft soil and treatment of discarded clay.


2017 ◽  
Vol 8 (2) ◽  
pp. 82-88
Author(s):  
Y. C. Fung ◽  
Shenbaga. R. Kaniraj

Soft soil does not have good soil properties and is not suitable for constructing pavement structures as shear strength is required to resist the shear stress developed by traffic loading. To increase shear strength in this study, lime is used as the soil stabilizing agent and fiber and mesh are used as the soil reinforcement materials. The proper amount of lime added to soil will increase the shear strength as the lime-treated soil will decrease moisture susceptibility and migration. Shear strength of the lime-treated soil can be further improved by adding reinforcement materials such as fiber and mesh. The reinforcement materials will interlock with groups of particles and provide tensile strength to the soil matrix. The type of soil used in this study is high plasticity elastic silt with sand which is classified using the Unified Soil Classification System (USCS). Quicklime (calcium oxide) is used in this study at the minimum amount required for stabilizing the soil, which is 9%. The amount of fiber and mesh added to the soil sample is 0.5% of the dry weight of the soil used. Cylindrical samples were prepared with a moisture content of 22% (OMC) for untreated soil and 21% (OMC) for lime-treated soil samples. The lime-treated soil samples were cured for 7, 14, 28, 56, 90 and 120 days. Unconfined compression tests were conducted to determine unconfined compressive strength (UCS) and stress-strain characteristics. The unconfined compressive strength of the lime-treated samples increased as curing period increased but the failure strain decreased. The UCS and failure strain for reinforced lime-treated soil samples are higher than the unreinforced lime-treated soil samples.


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