Increasing Density and Cement Content in Expansive Soils Stabilization:Conflicting or Complementary Procedures for Reducing Swelling?

2020 ◽  
Author(s):  
Nilo Cesar Consoli ◽  
Mariana Tonini de Araújo ◽  
Suéllen Tonatto Ferrazzo ◽  
Vinícius de Lima Rodrigues ◽  
Cecilia Gravina da Rocha
Keyword(s):  
Moisture Content ◽  
Portland Cement ◽  
Significant Influence ◽  
General Equation ◽  
Cement Content ◽  
Expansive Soils ◽  
Dry Density ◽  
Loss Of Mass ◽  
Porosity Index ◽  
Swelling Model

Present study makes three contributions to the literature of expansive soils: (i) it proposes equations to predict soil swelling based on dry density and cement content, (ii) it checks the developed general equation by predicting the swelling of different expansive soils from literature and (iii) it designs experiments that investigate factors that have a significant influence on swelling. An experimental programme was carried out to analyse the expansion of bentonite-kaolin-cement blends. Different proportions of bentonite-kaolin, cement content, dry density and moisture content were evaluated. A unique relation of the cement/porosity index was obtained for cement stabilized expansive soils swelling; this index has been used before to portray strength, stiffness and loss of mass of stabilized soils and is now shown to be applicable to describe swelling of expansive soils treated with Portland cement. In the present research, cement content and dry density are seen as conflicting parameters regarding the swelling of expansive soils, since increasing Portland cement amount reduces swelling and increasing density (through compaction) causes higher expansion. A general swelling model was proposed and successfully checked with data from the literature, being able to predict the swelling of expansive soils with different densities, expansive mineral, moisture and cement contents.

scholarly journals Assessing the Influence of Aggregates and Cement Types on Fresh Roller Compacted Concrete Mixture

2021 ◽  
pp. 23-31
Author(s):  
Saad I Sarsam
Keyword(s):  
Moisture Content ◽  
Portland Cement ◽  
Cement Content ◽  
Design Procedure ◽  
Concrete Mixture ◽  
Dry Density ◽  
Maximum Dry Density ◽  
River Sand ◽  
Roller Compacted Concrete ◽  
Crushed Aggregate

Roller compacted concrete mixture RCC is considered as a sustainable pavement construction material, it is a heavy-duty concrete mixture with zero slump. An attempt has been made in the present investigation to design the fresh RCC mixture using two types of coarse aggregates (crushed and rounded), two types of fine aggregates (silica and river sand) and two types of cement (ordinary Portland and sulphate resistance). Concrete mixtures with dense gradation were prepared and compacted according to modified proctor design procedure. A moisture-density test was used to determine the maximum density and optimum moisture content and of RCC mixtures for each mix.  Five different percentages of cement (10-18) % are implemented and six different percentages of moisture (4 – 8) %) % are used to determine the dry density-moisture content relationships. It was observed that the maximum dry density of rounded aggregates mixture is higher than that of crushed aggregate mixture by (4.2, 8.3, 4.2, 4.2, and 5.1) % and (4.1, 1.4, 4.1, 2.0, and 2.7) % for (18, 16, 14, 12, and 10) % cement content respectively for mixtures constructed with silica and river sands respectively with ordinary Portland cement. However, the maximum dry density of rounded aggregate mixture is higher than that of crushed aggregate mixture by (3.5, 4, 7.1, 5.5, and 4.4) % and (2.7, 4.8, 2.3, 4.4, and 4.2) % for (18, 16, 14, 12, and 10) % cement content respectively for mixtures constructed with silica and river sands respectively with sulphate resistance cement. It was concluded that 12 % of Portland cement and (6 to 7) % of moisture are proper combination when silica or river sand were implemented, while (12 and 14) % of sulphate resistance cement and (6 to 7) % of moisture are proper combination when silica or river sand were implemented. abstract must be a precise and reflection of what is in your article.

scholarly journals Influence of Energy on Compaction Characteristics of High Expansive Soils

2020 ◽  
Vol 9 (5) ◽  
pp. 1344-1348
Keyword(s):  
Moisture Content ◽  
Soil Type ◽  
Expansive Soils ◽  
Unit Weight ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Compaction Characteristics ◽  
Dry Unit Weight ◽  
Comparison Results ◽  
Compaction Energy

Each soil type has different behavior with regard to determination of maximum dry density and optimum moisture content and therefore any soil type has its own compaction requirements for experimental purposes and for control the compaction in the field. The general purpose of this study is to a better understanding of the compaction characteristics of high expansive soils, with emphasis on the relationships of moisture content and dry density of high expansive soils at a range of compaction energy levels. To achieve this purpose, high expansive soils samples were subjected to Atterberg limit and a set of laboratory compaction tests to find compaction characteristics namely; maximum dry unit weight and optimum water content of high expansive soils at different compaction energy (compaction effort) for different number of hammer blows per each layer range from 10 to 50, which varied the energy per unit volume from 356 KN/m3 to 1188 KN/m3.Rather than single peak compaction curves, the most achieved compaction curves are an irregular one and half peak compaction curves. According to the comparison results of different compaction energy, it was concluded that the maximum dry unit weight of high expansive soil was not highly affected by gradually increase of applied energy. The results showed that, the maximum dry density of tested expansive soils sample increased from 1.48g/cm3 to 1.6g/cm3 with increase of compaction energy from 356 KN/m3 to 1188 KN/m3.

scholarly journals Study on Creep Characteristics of Expansive Soil in High-Fill Channel of South-to-North Water Transfer Project

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Jianhua Guo ◽  
Zhangjun Dai ◽  
Shichang Li ◽  
Nadeem Muhammad ◽  
Hui Gao
Keyword(s):  
Moisture Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Water Transfer ◽  
Load Level ◽  
Dry Density ◽  
Creep Characteristics ◽  
North Water ◽  
Consolidation Coefficient ◽  
Unsaturated Expansive Soil

In the Nanyang section of the midroute of the South-to-North Water Transfer Project, the expansive soil is often used as a filler for high-fill channels. After the channel is stabilized, the expansive soil undergoes creep deformation over time. Studying the creep characteristics of expansive soils in different environments is particularly important for evaluating the safe operation of high-fill channels. In the current study, the creep test of expansive soil under different moisture content and dry density was carried out. It is proposed that the slope of the fitted straight line in the compression curve of the expansive soil can be used to represent the secondary consolidation coefficient of unsaturated expansive soil, and the variation law of the secondary consolidation coefficient under different environmental factors is obtained. The modified Bjerrum calculation method considering the influence of additional load and lateral deformation yields the postexpansion soil settlement curve model to determine the control index range of the project site. Moreover, it is also observed that the secondary consolidation coefficient of unsaturated expansive soil increases with the increase of moisture content and decreases with the increase of dry density. The coefficient of secondary compression of unsaturated expansive soil is linearly related to dry density and moisture content. After the preconsolidation treatment of the expansive soil, when the load level is less than the preload, the secondary consolidation coefficient is smaller, otherwise the secondary consolidation coefficient is larger.

scholarly journals Durability, strength, and stiffness of compacted gold tailings – cement mixes

2018 ◽  
Vol 55 (4) ◽  
pp. 486-494 ◽  
Author(s):  
Nilo Cesar Consoli ◽  
Anderson Peccin da Silva ◽  
Helena Paula Nierwinski ◽  
Jonatas Sosnoski
Keyword(s):  
Portland Cement ◽  
Ground Improvement ◽  
Endurance Performance ◽  
Dry Density ◽  
Significant Addition ◽  
Loss Of Mass ◽  
Strength And Stiffness ◽  
The Impact ◽  
Gold Tailings ◽  
Improvement Procedures

Compaction and Portland cement addition are amongst promising ground improvement procedures for enhancing the mechanical properties of gold tailings. The present investigation intends to compute the impact of Portland cement content and dry density on the properties (durability, stiffness, and strength) of compacted gold tailings – cement mixes. Its main significant addition to knowledge is the quantification of accumulated loss of mass (ALM) after wetting–drying cycles, shear modulus at small strains, and unconfined compressive strength (qu) as a function of the porosity/cement index. In addition, the existence of an exclusive relation connecting ALM divided by the number of wetting–drying cycles and porosity/cement index is revealed empirically. This broadens the applicability of such an index by demonstrating that it controls not only mechanical but also endurance performance of compacted gold tailings – Portland cement mixes.

Study about the Compacted Properties of Completely Weathered Granite Improved Soil

2012 ◽  
Vol 170-173 ◽  
pp. 482-485
Author(s):  
Yi Wen ◽  
Yong He Wang ◽  
Hong Bing Xiao ◽  
Chang Zi Qu
Keyword(s):  
Moisture Content ◽  
Cement Content ◽  
Optimum Moisture Content ◽  
Dry Density ◽  
Experiment Study ◽  
Maximum Dry Density ◽  
Compaction Characteristics ◽  
Weathered Granite ◽  
Working Out ◽  
Completely Weathered Granite

In this paper, through the indoor experiment study of compaction characteristics of completely weathered granite improved soil, analyse the relation of the maximum dry density and the optimum moisture content with lime and cement content, and through the fitting working out the relation curves and fitting formula of the improved soil of the maximum dry density and the optimum moisture content with lime and cement content . Provide reference for similar engineering.

scholarly journals Study on Mechanical Properties of the Expansive Soil Treated with Iron Tailings Sand

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chengfu Chu ◽  
Fei Zhang ◽  
Daoxiang Wu ◽  
Meihuang Zhan ◽  
Yun Liu
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Friction Angle ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Occlusal Force ◽  
Optimal Moisture Content ◽  
Tailings Sand

Aiming at researching shear strength parameters of expansive soil modified by industrial waste iron tailings sand, the enhancement of expansive soil is explored from macroscopic and microscopic aspects. After characterization and testing by various means, the results show that expansive soil modified by iron tailings sand will increase the maximum dry density of the improved soil and reduce its optimal moisture content, which is beneficial in tuning the moisture content at the construction site. In addition, iron tailings sand can improve the shear strength of expansive soils. The influence of iron tailings sand on cohesion increases first, then decreases, and reaches the peak value at 30%, while the effect on internal friction angle exhibits a continuously increasing trend. Furthermore, according to mercury intrusion tests and microangle analysis, the addition of iron tailings sand can reduce the tiny pores and enhance the occlusal force of the soil. Simultaneously, it increases the number of large pores, maximizing the macroscopic strengthening of iron tailings sand towards the expansive soil.

Pyrolysis of Hailar Lignite: Experiments with a Tubular Reactor and a Continuous Screw Kiln Reactor

2014 ◽  
Vol 672-674 ◽  
pp. 665-671
Author(s):  
Hao Jie Gao ◽  
Yue Zhao Zhu ◽  
Hai Jun Chen ◽  
Chuan Hua Liao ◽  
Yang Du ◽  
...  
Keyword(s):  
Moisture Content ◽  
Significant Influence ◽  
Tubular Reactor ◽  
Product Yield ◽  
Heating Process ◽  
Intermediate Products ◽  
Temperature Programmed ◽  
Gas Dilution ◽  
Pyrolysis Processes

Pyrolysis of Hailar lignite (moisture content ~ 34.81 wt%) was investigated at temperatures ranging from 700 °C to 900 °C in two different reactors: A tubular reactor (TR) and a continuous screw kiln reactor (CSKR). Under temperature programmed-heating conditions in the TR reactor, the auto-generated steam from the lignite moisture was vaporized and swept out of the reactor by the N2flow during the long heating process, leading to a weakened effect on the subsequent reactions. However, in the CSKR tests all the volatiles was generated continuously while avoid the carrier gas dilution , significant interactions between the in situ steam and the intermediate products occurred. Upon comparing the two pyrolysis processes, it was found the CSKR process exhibits higher H2yield of 23.23 mol/kg, H2proportion of 49.82 vol % than those (16.97 mol/kg, 41.51 vol %) from the TR process. The results demonstrated that inherent moisture in Hailar lignite had a significant influence on the product yield, depending on the pyrolysis conditions. It was also shown that increase in temperature led to rising dry gas yield and H2yield.

scholarly journals Pengaruh Penambahan Abu Arang Tempurung Kelapa Pada Tanah Lempung Terhadap Hasil Uji Kompaksi

2021 ◽  
Vol 3 (2) ◽  
pp. 276-285
Author(s):  
Brigita Suzanna ◽  
Irwan Lie Keng Wong ◽  
Monika Datu Mirring Palinggi
Keyword(s):  
Specific Gravity ◽  
Moisture Content ◽  
Physical Properties ◽  
Clay Soil ◽  
Test Method ◽  
Coconut Shell ◽  
Dry Density ◽  
Coconut Shell Ash ◽  
American Society ◽  
Index Value

The purpose of this research is to determine the physical properties of clay soil and to analyze the effect of adding coconut shell charcoal ash to the clay soil. The soil samples used in this study came from Tanralili District, Maros Regency, two sample points were taken and the variations in the levels of addition of coconut shell charcoal ash is 0%, 4%, 6%, 8%, 10%. The test method used refers to ASTM (American Society for Testing Materials). The tests carried out were testing the physical properties of the soil in the form of moisture content, specific gravity, Atterberg boundaries, filter analysis, and hydrometer analysis, then a compaction test was carried out to determine the maximum soil density. The results of the test obtained a moisture content value of 28.811%, a specific gravity of 2.58 g / cm3 so that it is classified as organic clay. As well as the plasticity index value of 9.926% with moderate plasticity from the 7% -17% interval. Then from the test results of soil compaction testing with the addition of coconut shell ash, the dry density (gdry) equal to 0.862, 0.886, 0.914, 0.943, 0.962, this means that the soil sample experienced an increase in dry density (gdry) of 11.60%. From the research results it can be concluded that the addition of coconut shell charcoal ash can increase the value of soil dry density so that it can be used to increase the value of the carrying capacity of clay soil.

scholarly journals Geotechnical Properties of Fresh and Degraded MSW in the Foothill of Shivalik Range Una, Himachal Pradesh

2019 ◽  
Vol 8 (2) ◽  
pp. 363-374 ◽  
Keyword(s):  
Moisture Content ◽  
Himachal Pradesh ◽  
Engineering Properties ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Overburden Pressure ◽  
Dump Site ◽  
Angle Of Internal Friction ◽  
Geotechnical Characteristics ◽  
Geotechnical Tests

The aim of the present study is to determine the physical and geotechnical characteristics of municipal solid waste (MSW) from an open dump site located in Una town, Himachal Pradesh (India) for the analysis of settlement and structural stability of landfill. Degraded waste was tested for different time intervals ranging from 6 months to 6 years. The physical characterization and the geotechnical tests were performed to determine the composition and the engineering properties of MSW respectively. The presence of moisture content in the fresh waste was 49.5±1.05% but for the degraded (or old) waste it varied between 39.8 to 51.6%. The specific gravity of fresh and old waste varied between 1.83±0.05 and 1.85 for 6 months old waste and 2.28 for 5-6 years old degraded waste respectively. The maximum dry density (MDD) was observed to be 4.28 kN/m2 for fresh waste at the optimum moisture content (OMC) of 78.1% and 4.47 kN/m3 for 6 months old waste and 6.25 kN/m3 for the degraded waste of 5-6 years at 80.2, 85.4% of OMC respectively. The hydraulic conductivity (k) of MSW was found to be decreasing with the degradation of MSW and the overburden pressure whereas the shear strength increased along with the degradation of the waste. The cohesion (c) and angle of internal friction (φ) increased respectively from 31.2 kPa(fresh) to 38 kPa(degraded) and 14° to 22° with the increase in waste degradation. The compression ratio of fresh waste was within the ranges of 0.19-0.29 and for degraded MSW it varied between 0.12 for 6 months old waste and 0.17 for 5-6 years old degraded waste respectively.

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