SUITABILITY OF RED MUD IN SUBGRADE USING RBI GRADE 81

Author(s):  
Kamal Singh ◽  
Hari Lal Tiwari

The waste generated by aluminum industry is known as bauxite residue or red mud. By nature, the red mud is toxic which creates problem for disposal. Due to the alkaline nature it is unsuitable for construction and vegetation. Every year more or less 75 million tons of red mud is generated worldwide. RBI grade 81 is a powdered cementitious stabilizer. It improves the engineering properties of several types of soils. This paper presents investigation carried out for better understanding on effect of RBI Grade 81 on red mud properties to be used in subgrades. It is found that with optimum dose of RBI grade 81 as 4%, liquid limit decreases and plastic limit increase. MDD values decrease slightly but the CBR value of the red mud increase with addition of RBI grade 81.

1978 ◽  
Vol 15 (2) ◽  
pp. 137-145 ◽  
Author(s):  
C. P. Wroth ◽  
D. M. Wood

Experimental evidence is produced to show that it is reasonable to assign a unique strength to all soils when at their respective liquid limits, and to redefine the plastic limit as the water content at which the strength is 100 times that at the liquid limit. Combining these assumptions with ideas of critical state soil mechanics it is then possible to relate the compression index of the remoulded soil to its plasticity index, and to suggest a unique relation between remoulded strength and liquidity index, irrespective of actual values of liquid and plastic limits. Field data from the Gulf of Mexico and from the North Sea are presented in support of these relations. The predictions of strength are best for overconsolidated clays, having water contents near the plastic limit.Recently in the United Kingdom the cone penetrometer has become the recommended test for determination of the liquid limit, in preference to the Casagrande test. Having redefined the plastic limit it would be logical to use the cone penetrometer to determine this too, by using cones with different weights. Experimental data are shown to illustrate and support this proposal.


2018 ◽  
Vol 7 (2.1) ◽  
pp. 24
Author(s):  
Sajja Satish ◽  
Shyam Prakash Koganti ◽  
Kommineni Hemantha Raja ◽  
Kaza Raaga Sai

Expansive soil (Black cotton soil) is very weak and does not have enough stability for any type of construction work. To make the subgrade soil stable, by improving its engineering properties is very essential. In the present work, stabilization of subgrade soil by using Sand and Cement varying percentage of cement as 2%, 3%, 5% and constant percentage of sand by weight of soil, Rice Husk of 5%, 7%, 10%, and Lime is used to enhance the strength of subgrade soil. The purpose of this study is to determine the optimum dose of the stabilizer, which improves the strength and bearing capacity of soil less which is suitable for pavement structure. To evaluate the strength of soil, various tests have been performed such as Sieve analysis, Liquid limit, Plastic limit, Specific gravity, Compaction (OMC, MDD) and CBR test in the laboratory. The result shows that the use of the above materials in combination increases the California Bearing Ratio values (CBR). By using the CBR value the design of pavements to carry traffic in the range of 1 to 10 msa and 10 – 150 msa is calculated as per IRC: 37 – 2001.


2015 ◽  
Vol 9 (1) ◽  
pp. 46-51 ◽  
Author(s):  
Zhu Lei

There are a large number of high liquid limit soil distributed in southern China. As one of the special soils commonly seen in highway construction, high liquid limit soil cannot be used in subgrade filling directly due to its special engineering properties. With the idea of saving engineering investment and protecting environment, high liquid limit soil must be improved to be qualified subgrade filling material. First, detailed laboratory tests are carried out to reveal the special properties of high liquid limit soil. Then, based on the characters of high liquid limit soil, the improving tests of liquid plastic limit, unconfined compressive strength, CBR and compaction are completed by adding different percentages of quicklime and white lime to the high liquid limit soil to study the change in the physical and mechanical properties and strength. The results show that, after being improved by lime, the high liquid limit soil can be used as subgrade filling of expressway as its liquid limit, plastic index being reduced, the strength increased and the value of CBR increased remarkably, and modified effectiveness of quicklime is better than that of white lime. Through comparison and analysis of the test results, it is found that high liquid limit soil with 5% quicklime can be used as subgrade filling material for highway since it is not only economical but also qualified to meet the requirement of improvement and strength.


2021 ◽  
Vol 171 ◽  
pp. 105645
Author(s):  
Sandeep Panda ◽  
Rachel Biancalana Costa ◽  
Syed Sikandar Shah ◽  
Srabani Mishra ◽  
Denise Bevilaqua ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Suchita Rai ◽  
Dilip H. Lataye ◽  
M. J. Chaddha ◽  
R. S. Mishra ◽  
P. Mahendiran ◽  
...  

“Red mud” or “bauxite residue” is a highly alkaline waste generated from alumina refinery with a pH of 10.5–12.5 which poses serious environmental problems. Neutralization or its treatment by sintering in presence of additives is one of the methods for overcoming the caustic problem as it fixes nearly all the leachable free caustic soda present in red mud. In the present study, feasibility of reducing the alkaline nature of red mud by sintering using fly ash as an additive via Taguchi methodology and its use for brick production, as an alternative to clay, is investigated. The analysis of variance (ANOVA) shows that sintering temperature is the most significant parameter in the process. A pH of 8.9 was obtained at 25–50% of red mud and 50–75% fly ash with water and temperature of . Alternatively 50% of red mud can be mixed with 50% of fly ash with water at temperature of to get a pH of about 8.4. The mechanism of this process has been explained with also emphasis on chemical, mineralogical, and morphological analysis of the sintered red mud. The results would be extremely useful in utilization of red mud in building and construction industry.


2000 ◽  
Vol 37 (3) ◽  
pp. 712-722 ◽  
Author(s):  
A Sridharan ◽  
H B Nagaraj

Correlating engineering properties with index properties has assumed greater significance in the recent past in the field of geotechnical engineering. Although attempts have been made in the past to correlate compressibility with various index properties individually, all the properties affecting compressibility behaviour have not been considered together in any single study to examine which index property of the soil correlates best with compressibility behaviour, especially within a set of test results. In the present study, 10 soils covering a sufficiently wide range of liquid limit, plastic limit, and shrinkage limit were selected and conventional consolidation tests were carried out starting with their initial water contents almost equal to their respective liquid limits. The compressibility behaviour is vastly different for pairs of soils having nearly the same liquid limit, but different plasticity characteristics. The relationship between void ratio and consolidation pressure is more closely related to the shrinkage index (shrinkage index = liquid limit - shrinkage limit) than to the plasticity index. Wide variations are seen with the liquid limit. For the soils investigated, the compression index relates better with the shrinkage index than with the plasticity index or liquid limit.Key words: Atterberg limits, classification, clays, compressibility, laboratory tests.


2021 ◽  
Vol 13 (20) ◽  
pp. 11298
Author(s):  
Alessio Occhicone ◽  
Mira Vukčević ◽  
Ivana Bosković ◽  
Claudio Ferone

The aluminum Bayer production process is widespread all over the world. One of the waste products of the Bayer process is a basic aluminosilicate bauxite residue called red mud. The aluminosilicate nature of red mud makes it suitable as a precursor for alkali-activated materials. In this work, red mud was mixed with different percentages of blast furnace slag and then activated by sodium silicate solution at different SiO2/Na2O ratios. Obtained samples were characterized by chemical–physical analyses and compressive strength determination. Very high values of compressive strength, up to 50 MPa, even for high percentage of red mud in the raw mixture (70 wt.% of RM in powder mixture), were obtained. In particular, the higher compressive strength was measured for cubic samples containing 50 wt.% of RM, which showed a value above 70 MPa. The obtained mixtures were characterized by no or scarce environmental impact and could be used in the construction industry as an alternative to cementitious and ceramic materials.


2020 ◽  
Vol 14 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Hai-Bang Ly ◽  
Binh Thai Pham

Background: Shear strength of soil, the magnitude of shear stress that a soil can maintain, is an important factor in geotechnical engineering. Objective: The main objective of this study is dedicated to the development of a machine learning algorithm, namely Support Vector Machine (SVM) to predict the shear strength of soil based on 6 input variables such as clay content, moisture content, specific gravity, void ratio, liquid limit and plastic limit. Methods: An important number of experimental measurements, including more than 500 samples was gathered from the Long Phu 1 power plant project’s technical reports. The accuracy of the proposed SVM was evaluated using statistical indicators such as the coefficient of correlation (R), Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) over a number of 200 simulations taking into account the random sampling effect. Finally, the most accurate SVM model was used to interpret the prediction results due to Partial Dependence Plots (PDP). Results: Validation results showed that SVM model performed well for prediction of soil shear strength (R = 0.9 to 0.95), and the moisture content, liquid limit and plastic limit were found as the three most affecting features to the prediction of soil shear strength. Conclusion: This study might help in quick and accurate prediction of soil shear strength for practical purposes in civil engineering.


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