scholarly journals Influence of Curing Temperature on Shear Strength and Compressibility of Swelling Soil Stabilized with Hydrated Lime

2021 ◽  
Author(s):  
Nihad Bahaaldeen Salih ◽  
◽  
Tavga Aram Abdalla ◽  
Keyword(s):  
Cohesive Soil ◽  
Hydrated Lime ◽  
Dry Mass ◽  
Liquid Limit ◽  
Curing Temperature ◽  
Temperature Changes ◽  
Northern Iraq ◽  
Swelling Soil ◽  
Environmental Events ◽  
Compressibility Characteristics

The exposed cohesive soils to temperature can face considerable physical and mechanical characteristics changes. Therefore, understanding the environmental events influences on the soil geotechnical properties is essential, which is significant in the rainy and cold places such as in Sulaimani city, northern Iraq. This experimental study examines the temperature changes (10o C, and 50o C) impacts on the durability of stabilized cohesive soil using 0%, 5%, 10% and 15% hydrated-lime added as a replacement on the soils dry mass. Consistency, unconfined compression, and compressibility characteristics were evaluated. Under the applied circumstances, a decrease was noticed in the magnitudes of liquid limit and plasticity index, while plastic limit generally increased within hydrated-lime percent increase. The study yielded an appreciable improvement of the cohesive soil’s strength and compressibility properties with time progress, especially after the stabilization process is achieved.

scholarly journals Prediction of Consolidation Characteristics from Index Properties

2018 ◽  
Vol 65 ◽  
pp. 06004
Author(s):  
Kok Shien Ng ◽  
Yee Ming Chew ◽  
Nur Izzati Ahmad Lazim
Keyword(s):  
Regression Analysis ◽  
Cohesive Soil ◽  
Liquid Limit ◽  
Index Properties ◽  
Compression Index ◽  
Plastic Limit ◽  
Considerable Time ◽  
Coefficient Of Consolidation ◽  
Good Relationship ◽  
Two Parameters

Compression index and coefficient of consolidation are two most important parameters in obtaining the consolidation characteristics of cohesive soil. Considerable time and effort are required to obtain these parameters from the oedometer test. Therefore, this study aims to correlate these two parameters with the index properties. Five remoulded samples are tested for their physical properties as well as their consolidation characteristics. The results show good relationship was obtained for the liquid limit and the compression index while the coefficient of consolidation is best correlated with the plastic limit. Multiple regression analysis was performed to improve the prediction. Liquid limit is best coupled with specific gravity to estimate the compression index while plastic limit and plastic index can be used to best predict the coefficient of consolidation.

scholarly journals Estimation of physical and mechanical properties of cohesive soil stabilized by hydratized lime addition

2013 ◽  
Vol 45 (2) ◽  
Author(s):  
Wojciech Sas ◽  
Andrzej Głuchowski ◽  
Jarosław Margielski
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Cohesive Soil ◽  
Hydrated Lime ◽  
Chemical Stabilization ◽  
Cohesive Soils ◽  
Silty Clay ◽  
Cbr Test ◽  
The Impact ◽  
Lime Addition

AbstractEstimation of physical and mechanical properties of cohesive soil stabilized by hydratized lime addition. Process of chemical stabilization of cohesive soils influences its mechanical properties, also in the case of soil cohesion. Road constructions consist of few layers which have various mechanical properties and this creates the need for better understanding the impact of chemical stabilization on soil as a layer of road. For the purposes of this article, tests were carried out in order to establish physical and mechanical properties, especially the penetrating resistance CBR test. The main aim of this paper was to estimate the cohesion of the soil, which was sandy-silty clay stabilized with hydrated lime

scholarly journals Prediction of California Bearing Ratio from Consistency and Compaction Characteristics of Fine-grained Soils

2021 ◽  
Vol 24 (2) ◽  
pp. 123-129
Author(s):  
Kamal Ahmed Rashed ◽  
Nihad Bahaaldeen Salih ◽  
Tavga Aram Abdalla
Keyword(s):  
Statistical Analysis ◽  
Liquid Limit ◽  
Multiple Regression Equation ◽  
Natural Soil ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Compaction Characteristics ◽  
Northern Iraq ◽  
Fine Grained ◽  
Successful Design

Soil’s characteristics are essential for the successful design of projects such as airports runway and flexible pavement. CBR (California Bering Ratio) is one of the significant soil characteristics for highways and airports projects. Thus, the CBR property can be used to determine the subgrade reaction of soil through correlations. Many of the soil geotechnical parameters such as compaction characteristics (Maximum Dry Density, MDD; Optimum Moisture Content, OMC), and consistency parameters (Liquid Limit, LL; Plastic Limit, PL; Plasticity Index, PI) can be in charge of changes that happen in soil CBR value. Soaked and/or non-soaked conditions of soils also affect CBR value. Hence, testing soils in a laboratory for CBR calculation is time-consuming that needs notable effort. Therefore, this study aims to generate some useful correlations for soil’s CBR with compaction and consistency parameters for 85 samples of fine-grained soils. The study trials were applied on natural soil samples of various places in Sulaimani Governorate, Northern Iraq. Statistical analysis has been carried out by using SPSS software (Version 28). Soaked CBR is counted, which is important for conditions such as rural roads that remain prone to water for few days. Based on the statistical analysis, there is a significant correlation between LL, PL, PI, MDD, and OMC with CBR as the dependent variable as a single variable equation with R2 of  0.7673, 0.5423, 0.5192, 0.6489, and 0.51, respectively. In addition, the highest value of R2 correlation was obtained between CBR value with consistency and compaction properties as a multiple regression equation with R2 of 0.82. The obtained equations for correlation purposes are successfully achieved and can be used, notably, to estimate CBR value.

scholarly journals Influence of randomly oriented fibres on shear strength of mineral soils

2019 ◽  
Vol 52 (2) ◽  
pp. 235
Author(s):  
Tymoteusz Zydroń ◽  
Andrzej Gruchot
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Shear Velocity ◽  
Cohesive Soil ◽  
Dry Mass ◽  
Soil Test ◽  
Test Results ◽  
Medium Sand ◽  
Mineral Soils ◽  
Direct Shear Apparatus

The purpose of the paper was to determine two things: the influence of type and amount of reinforcement on shear strength of soil and the relation between the efficiency of reinforcement and soil moisture content. Shear strength was determined in a direct shear apparatus in a box with a square section of 80x80 mm. The range of normal stress was from 25 to 150 kPa and the shear velocity was 1.0 mm×min<sup>-1</sup>. The tests were carried out on medium sand and clayey coarse silt at two moisture contents and with two types of reinforcement - polyolefine fibres and 40x3 mm foil stripes. The addition of reinforcement was 0.5 and 1.0% in relation to the dry mass of soil. Test results indicated that using polyolefine fibres as dispersed reinforcement in a sandy soil increased its shear strength. Whereas the influence of using foil stripes on shear strength was little. However, using both types of reinforcement in a cohesive soil increased its shear strength and this influence was particularly clear at higher moisture content.

Empirical equation for evaluating the dispersivity of cohesive soil

2013 ◽  
Vol 50 (9) ◽  
pp. 989-994 ◽  
Author(s):  
Henghui Fan ◽  
Lingwei Kong
Keyword(s):  
Empirical Equation ◽  
Clay Content ◽  
Cohesive Soil ◽  
Liquid Limit ◽  
Sodium Ion ◽  
Alkaline Ph ◽  
Electrolyte System ◽  
High Sodium ◽  
Chemical Indicators ◽  
Physical And Chemical

As indicated by the theory of a clay–water–electrolyte system, the dispersive mechanism of cohesive soil involves three aspects: low clay content, high sodium ion percentage, and strongly alkaline pH. Accordingly, an empirical equation was established with an associated procedure and criteria proposed for evaluating the dispersivity of cohesive soil. The equation consists of four soil physical and chemical indicators: liquid limit (WL), clay content (PC), sodium percentage in the pore water (PS), and pH. The equation is F = 4 − 0.01(2WL + PC − PS) + 0.1 pH, where F is the soil dispersivity value. Compared with the evaluation based on laboratory tests, the empirical equation had higher accuracy for the evaluation of the dispersivity of cohesive soil, and was thus conducive to greater engineering safety. This indicates that the proposed empirical equation is applicable for evaluating the dispersivity of cohesive soil in general engineering.

scholarly journals Analysis of Geotechnical Characteristics of Coastal Clay Soil Found in Incheon and Gwangyang

2021 ◽  
Vol 21 (5) ◽  
pp. 229-235
Author(s):  
Sungyeol Lee ◽  
Wonjin Baek ◽  
Hwabin Ko ◽  
Daeho Kim ◽  
Gilsang Lim ◽  
...  
Keyword(s):  
Water Content ◽  
Natural Water ◽  
Clay Soil ◽  
Cohesive Soil ◽  
Liquid Limit ◽  
Compression Index ◽  
Geotechnical Characteristics ◽  
Natural Water Content ◽  
Planning And Construction ◽  
Physical And Mechanical Characteristics

Recently, there has been an increase in the number of projects involving the planning and construction of business complex facilities and land development in coastal regions. However, coastal regions are characterized by very soft clay soil. Consequently, such clay soil needs to be augmented for facilitating land procurement. Furthermore, to realize land improvement, the associated geotechnical characteristics need to be analyzed through laboratory tests by acquiring pristine samples of cohesive soil. According to the results obtained from previous studies, the characteristics of the cohesive soil found in Korea can vary depending on the region and depositional environment. The objective of this study is to examine the representative physical and mechanical characteristics of marine clay found in Namhae coast (Gwangyang) and Seohae coast (Incheon) by comparing and analyzing these characteristics. To this end, land examinations were conducted during planning and construction, and data were gathered from 445 sites in Incheon and 844 sites in Gwangyang for comparing the associated physical and mechanical characteristics. Subsequently, by conducting regression analysis, equations of correlation between liquid limit and natural water content, effective surface load and pre-consolidation load, compression index and liquid limit, and compression index and natural water content were deduced. The obtained results indicate that compared to the soil found in Incheon, the clay fraction, natural water content, liquid limit, plasticity index, liquidity index, initial void ratio, and compression index of the soil found in Gwangyang are higher.

scholarly journals The Effect of Root Media on Root-zone pH, Calcium, and Magnesium Management in Containers with Impatiens

1997 ◽  
Vol 122 (2) ◽  
pp. 275-284 ◽  
Author(s):  
William R. Argo ◽  
John A. Biernbaum
Keyword(s):  
Root Zone ◽  
Linear Regression Analysis ◽  
Hydrated Lime ◽  
Dry Mass ◽  
Linear Increase ◽  
Sphagnum Peat ◽  
Shoot Tissue ◽  
Root Media ◽  
The Media ◽  
Over Time

Hybrid impatiens (Impatiens Wallerana Hook. F.) were planted in six root media containing either 70% (by volume) rockwool, coir, or four types of sphagnum peat and 30% perlite. The six media varied in cation exchange capacities (CEC) (from 5 to 76 meq·L-1) and the amount of a dolomitic hydrated lime [Ca(OH)2 and Mg(OH)2 at 0 to 4.5 kg·m-3) required to obtain an initial pH of ≈6.0. Two additional treatments were produced by using a dolomitic carbonate lime (CaCO3 and MgCO3) at 8.4 kg·m-3 instead of the hydrated lime in two of the sphagnum peat media. Plants were subirrigated for 17 weeks using three nutrient solutions (NS) that contained at 200N-20P-200K mg·L-1 but had a variable NH4 : NO3 ratio and Ca2+ and Mg2+ content. The NS were designed to produce either acidic, neutral, or basic reactions in the medium. In media containing the hydrated lime, the NS was the primary factor controlling medium pH. However, within each NS treatment, the media did have some effect on buffering the pH over time. There was a linear increase in shoot-tissue Ca and Mg as the applied concentration of Ca2+ increased from 18 to 156 mg·L-1 and that of Mg2+ increased from 5 to 56 mg·L-1. Linear regression analysis of shoot-tissue Ca and Mg based on their concentration in the NS indicated a similar overall decrease in the Ca and Mg supply in all six root media over time. For plants grown in media containing the carbonate lime, shoot dry mass was similar to that of plants grown in the same media with hydrated lime. The presence of the carbonate lime in the media increased the pH buffering capacity against decreasing pH with the acidic and neutral NS but not against increasing pH with the basic NS. In the media containing the carbonate lime and given the acidic NS, root-medium and shoot-tissue Ca and Mg increased by weeks 12 and 17 compared to that of the same medium containing the hydrated lime. There were minimal differences in root-media and shoot-tissue Ca and Mg concentration between lime treatments when given the neutral or basic NS.

scholarly journals Growth and Pigment Content of Container-grown Impatiens and Petunia in Relation to Root Substrate pH and Applied Micronutrient Concentration

HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1421-1425 ◽  
Author(s):  
Brandon R. Smith ◽  
Paul. R. Fisher ◽  
William R. Argo
Keyword(s):  
Hydrated Lime ◽  
Plant Size ◽  
Dry Mass ◽  
Leaf Length ◽  
Pigment Content ◽  
Crop Species ◽  
Lower Solubility ◽  
Micronutrient Concentration ◽  
Highly Correlated ◽  
Substrate Ph

The objective was to quantify the effect of substrate pH and micronutrient concentration on growth and pigment content for two floricultural crop species, Petunia ×hybrida `Priscilla' and Impatiens wallerana `Rosebud Purple Magic'. A 70% peat: 30% perlite medium was amended with dolomitic hydrated lime to achieve five substrate pH's ranging from pH 4.4 to 7.0. Plants were grown in 10-cm-diameter pots in a greenhouse for 4 weeks, and irrigated with a fertilizer containing (in mg·L-1) 210N-31P-235K-200Ca-49Mg. Micronutrients were applied using an EDTA (ethylenedinitrilotetraacetic acid) chelated micronutrient blend (C111), at 1×, 2×, and 4× concentrations (in mg·L-1) of 0.50Fe-0.25Mn-0.025Zn-0.04Cu-0.075B-0.01Mo. Petunia shoot dry mass and stem caliper decreased as substrate pH increased, whereas leaf length and width remained unchanged. The highest level of C111 resulted in higher dry mass and smaller leaf area compared with other C111 levels. Overall, substrate pH and C111 had little effect on plant size or mass for impatiens. For both species, increasing substrate pH above 5.3 resulted in a decline in chlorophyll, carotenoids, and the SPAD chlorophyll index (measured with a Minolta-502 SPAD meter) compared with the lowest three pH levels. Chlorosis was observed at pH 7 after 2 weeks of growth. Increasing C111 concentration had no effect on pigment content below pH 5.3, but increased pigment content at higher pH levels. The SPAD index was highly correlated with chlorophyll content. This research emphasizes that an acceptable range in substrate pH can vary depending on fertilizer practices, with higher micronutrient concentration compensating for lower solubility at high substrate pH.

scholarly journals Using the Effective Void Ratio and Specific Surface Area in the Kozeny–Carman Equation to Predict the Hydraulic Conductivity of Loess

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 24 ◽  
Author(s):  
Bo Hong ◽  
Xi’an Li ◽  
Li Wang ◽  
Lincui Li ◽  
Quan Xue ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Permeability Coefficient ◽  
Void Ratio ◽  
Geometric Mean ◽  
Cohesive Soil ◽  
Liquid Limit ◽  
Published Data ◽  
Effective Void Ratio

Many modified Kozeny–Carman (KC) equations have been used to predict the saturated permeability coefficient (Ks) of porous media in various fields. It is widely accepted that the KC equation applies to sand but does not apply to clay. Little information is available to clarify this point. The effectiveness of the KC equation will be evaluated via laboratory penetration tests and previously published data, which include void ratio, specific surface area (SSA), liquid limit (LL), and permeability coefficient values. This paper demonstrates how to estimate the SSA of cohesive soil from its LL. Several estimation algorithms for determining the effective void ratio (ee) of cohesive soil are reviewed. The obtained results show that, compared to the KC equation based on porosity and geometric mean particle size (Dg), the KC equation based on the SSA and the ee estimation algorithm can best predict the Ks of remolded loess. Finally, issues associated with the predictive power of the KC equation are discussed. Differences between measured and the predicted Ks values may be caused by the uniformity of the reconstructed specimen or insufficient control of the test process and errors in the SSA and ee.

scholarly journals A Practical Approach for Data Gathering for Polymer Cure Simulations

2018 ◽  
Vol 8 (11) ◽  
pp. 2227 ◽  
Author(s):  
Søren Heinze ◽  
Andreas Echtermeyer
Keyword(s):  
Data Gathering ◽  
Good Control ◽  
Isoconversional Method ◽  
Curing Temperature ◽  
Scanning Calorimetry ◽  
Simple Method ◽  
Finite Element Program ◽  
Temperature Changes ◽  
Model Free ◽  
Element Program

Producing precision parts requires good control of the production parameters. When casting thermoset polymers an understanding of the curing process, with its heat release and associated temperature changes, is important. This paper describes how the cure of a polymer of unknown detailed chemical composition in a large part can be predicted and how the necessary material properties required for the predictions can be obtained. The approach given is a relatively simple method that a part manufacturer can perform. It will not characterize chemical reactions in detail, but it gives sufficient accuracy to describe the process. The procedures will be explained for an example of casting a large block of a filled two-component thermoset polyurethane. The prediction of the degree of cure, the associated heat and temperature increase during the curing of a polymer was successfully done using a standard finite element program with the input parameters reaction energy, the Arrhenius pre-factor and the kinetic function, which describes the chemical reaction. The three parameters could be obtained with standard Differential Scanning Calorimetry (DSC) equipment. The data were analyzed with the model-free isoconversional method combined with the compensation effect. The same set of parameters allowed the prediction of experimental cure behavior over two orders of magnitude of time and at a curing temperature range from room temperature up to 420 K.

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