scholarly journals Experimental Study on Improvement of Marine Soft Soil with Alkali Residue

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.


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.


2020 ◽  
pp. 10-17
Author(s):  
Qi Daozheng ◽  
Gu Cong ◽  
Fu Jiajia ◽  
Wang Yao

The effects of polypropylene fiber reinforcement on shear strength and unconfined compressive strength of silty soft soil in tidal flats were studied. Through shear test and unconfined compression test, Experimental study was conducted on silty soft soil of allene fiber reinforced beach with 0~0.6% different mass content and 3 ~18m different length. The failure process and mechanism of fiber reinforced soil samples were also discussed. The test results show that: Shear strength (cohesion and internal friction Angle) and unconfined compressive strength increased rapidly in the early stage with the increase of fiber content, and gradually decreased after reaching the peak at a certain content. In this test, the optimal fiber length corresponding to shear strength is 9mm. When the content is less than 0.6%, the optimal content of cohesion is about 0.2%, and the optimal content corresponding to the Angle of internal friction is between 0.2% and 0.3%. Within the range of 18mm fiber length in the experimental study, unconfined compressive strength increased with the increase of fiber length, and the optimal fiber content corresponding to unconfined compressive strength was 0.2%. The main effects of polypropylene fiber reinforcement on soil cohesion and unconfined compressive strength are not obvious.


2013 ◽  
Vol 689 ◽  
pp. 324-328
Author(s):  
Xin Shan Zhuang ◽  
Can Zhao ◽  
Xu Min Wang

Unconfined compressive strength tests and calcium carbonate (CaCO3) quantitative chemical tests are conducted on artificially cemented sand which have different cement ratio (Cv) and curing time (t). Through the analysis of experimental results, the unconfined compressive strength (qu) of cemented sand are affected by curing time (t), cement ratio (Cv) and void ratio (η). Test results show that the longer the curing time (t), the lower the void/cement ratio (η/Cv) and the higher calcium carbonate/calcium hydroxide content ratio (CaCO3/Ca(OH)2 ratio or mC/mH), the higher the unconfined compressive strength (qu) of cemented sand. It is established the compressive strength equation based on the variables of cement ratio (Cv), void ratio (η) and curing time (t). By mC/mH-qu curve analysis, it is obtained the quantitative relation of chemical composition and mechanical strength.


Author(s):  
Harish R ◽  
Ramesh S ◽  
Tharani A ◽  
Mageshkumar P

This paper presents the results of an experimental investigation of the compressive strength of concrete cubes containing termite mound soil. The specimens were cast using M20 grade of concrete. Two mix ratios for replacement of sand and cement are of 1:1.7:2.7 and 1:1.5:2.5 (cement: sand: aggregate) with water- cement ratio of 0.45 and varying combination of termite mound soil in equal amount ranging from 30% and 40% replacing fine aggregate (sand) and cement from 10%,15%,20% were used. A total of 27 cubes, 18 cylinders and 6 beams were cast by replacing fine aggregate, specimens were cured in water for 7,14 and 28 days. The test results showed that the compressive strength of the concrete cubes increases with age and decreases with increasing percentage replacement of cement and increases with increasing the replacement of sand with termite mound soil cured in water. The study concluded that termite mound cement concrete is adequate to use for construction purposes in natural environment.


2020 ◽  
Vol 998 ◽  
pp. 323-328
Author(s):  
Achmad Bakri Muhiddin ◽  
Marthen M. Tangkeallo

In remote areas, most roads still use pavements that are very sensitive to climate change, especially those using clay pavements with high plasticity. In addition to the issue of cost, the difficulty of obtaining a proper source of material is another problem that has led to soaring prices for materials. In this regard, a study was conducted using local materials, namely zeolite as a stabilizing material added with waterglass as activating agent. The research began with samples of laterite soil and natural zeolite for XRD test (microstructure testing), and then testing for laterite soil’s index properties and engineering properties, namely Unconfined Compressive Strength and CBR value. The purpose of the test is to determine the correlation between the Unconfined Compressive Strength (UCS) and the soil bearing capacity (CBR) caused by adding zeolite as stabilizer material and waterglass as activator with increasing curing time. Laterite soils contain a brownish red iron oxide. The stabilizing material zeolite contains a crystalline mineral of alumina silicate SiO2. While waterglass composed of sodium meta silicate. Stabilization carried out by mixing 4%, 8%, 12%, 16%, and 20% of zeolite with addition of 2% waterglass, percentage was measured based on soil dry weight. Specimens were tested at curing time of 0, 7, 14, and 28 days. The test result shows increasing UCS and CBR values with increasing percentage of zeolite. At mix of 20% zeolite and 2% waterglass, the unconfined compressive strength reaches 23.54 kg/cm2 with CBR value 58% at 28 days of curing time.


2019 ◽  
Vol 814 ◽  
pp. 399-403
Author(s):  
Anuchit Uchaipichat

This paper presents the relationship between the dynamic cone penetration (DCP) test results and the unconfined compressive strength of lateritic cemented soils. A series of DCP tests and unconfined compressive strength was performed on lateritic cemented soil. The soils sample used in this study was lateritic soil. The test results for the DCP tests are presented in terms of penetration index. It can be observed that the penetration index decreased with increasing curing period and cement content. Moreover, the unconfined compressive strength of cemented soils increased with curing period and cement content. The relationship between unconfined compressive strength and penetration index is presented. A unique relationship for unconfined compressive strength can be obtained.


2012 ◽  
Vol 512-515 ◽  
pp. 2908-2913 ◽  
Author(s):  
Yu Cheng Kan ◽  
Hsuan Chih Yang ◽  
Kuang Chih Pei

This paper presents an experimental study dealing with the toughness of heavy concrete based on the ASTM C1018. Mixtures including 0%, 0.5%, 1.0% and 1.5% of steel fiber content by volume are designated, which are developed based on a mixture used in Kuosheng nuclear power plant in Taiwan. Metallic aggregates of iron shots and iron ore take 48.8% by volume in that mixture. Test results reveal that the compressive strength and rupture modulus of heavy concrete turn out higher than those of normal concrete. In addition, flexural toughness of heavy concrete grow with the steel fiber fraction, which is valid and appropriate for construction of shielding structure and spent fuel cask.


2019 ◽  
Vol 25 (2) ◽  
pp. 127-139 ◽  
Author(s):  
Johnson R. Oluremi ◽  
Adrian O. Eberemu ◽  
Stephen T. Ijimdiya ◽  
Kolawole J. Osinubi

ABSTRACTInherent variability in engineering properties of lateritic soil in relation to its plasticity, permeability, strength, workability, and natural moisture content, has made it an unpredictable material for use in civil engineering works, resulting in the need for its treatment by stabilization. A lateritic soil classified as A-6(6) and CL, according to American Association of State Highway and Transportation Officials and Unified Soil Classification System of ASTM (2011), was treated with up to 10 percent waste wood ash (WWA). Compaction was carried out using four energies, namely, reduced British Standard light, British Standard light (BSL), West African Standard, and British Standard heavy, on samples, which were then examined for hydraulic conductivity, volumetric shrinkage, and unconfined compressive strength as major criteria for use as liner and for the development of acceptable zones. Specimens with 4 percent WWA content compacted with a minimum BSL energy satisfied the maximum hydraulic conductivity (k) value of 1 × 10−9 m/s, maximum volumetric shrinkage strain of 4 percent, and minimum unconfined compressive strength value of 200 kN/m2 required for use as liner in engineered landfills. The overall acceptable zone was enlarged for up to 4 percent WWA content, thereby accommodating higher moulding water content, but the minimum compactive effort required to achieve it became reduced. The beneficial treatment of lateritic soil with up to 4 percent WWA will perform satisfactorily as liner and covers in waste containment application and will minimize the pollution and environmental impact of wood waste disposal.


2006 ◽  
Vol 43 (3) ◽  
pp. 294-309 ◽  
Author(s):  
Zahid Khan ◽  
Anwar Majid ◽  
Giovanni Cascante ◽  
D Jean Hutchinson ◽  
Parsa Pezeshkpour

The effect of variation in cement content, initial water content, void ratio, and curing time on wave velocity (low-strain property) and unconfined compressive strength (large-strain property) of a cemented sand is examined in this paper. The measured pulse velocity is compared with predictions made using empirical and analytical models, which are mostly based on the published results of resonant column tests. All specimens are made by mixing silica sand and gypsum cement (2.5–20% by weight) and tested under atmospheric pressure. The wave velocity reaches a maximum at optimum water content, and it is mostly affected by the number of cemented contacts; whereas compressive strength is governed not only by the number of contacts but also by the strength of contacts. Experimental relationships are developed for wave velocity and unconfined compressive strength as functions of cement content and void ratio. Available empirical models underpredict the wave velocity (60% on average), likely because of the effect of microfractures induced by confinement during the testing. Wave velocity is found to be a good indicator of cement content and unconfined compressive strength for the conditions of this study.Key words: wave velocity, low-strain stiffness, cemented sands, elastic moduli, unconfined compressive strength.


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