scholarly journals An Experiment on Incorporation of Bentonite Clay in Mortar

2020 ◽  
Vol 8 (5) ◽  
pp. 3866-3873
Keyword(s):  
Clay Mineral ◽  
Chemical Weathering ◽  
Shear Failure ◽  
Bentonite Clay ◽  
Stone Masonry ◽  
Major Constituent ◽  
Fine Aggregate ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Fixed Proportion

Mortar refers to a binding paste which is workable in nature and consistency, used as a binder in construction activities such as stone bonding in stone masonry, brick bonding in brick masonry and as well as in concrete works. Mortar is often used as a means for decorative works attaining to its workable nature, which in this project I have intended to enhance. Mortar is further used as a sealant in order to fill cracks and gaps within the structure. The term mortar is taken from the Latin term “ mortarium” which means crushed. Mortar is often prepared by mixing a suitable binder, fine aggregate or in simpler terms sand and water by a fixed proportion by mass or volume. The ratio of the constituents depends on the quality and magnitude of the work being done. Mortar gains its strength due to the various chemical reactions that occur while the mortar is being cured in water, gaining 99% strength in 28 days. The most used binder in modern times is Portland cement, which was used at the onset of 20th century. A common binder prevailing in the past was lime and the associated mortar mix was called lime mortar. A major part of this project lies in the use of clay as a substitute for sand in mortar. Clay refers to a fine-grained soil deriving its origin from naturally occurring rocks that have undergone chemical weathering. Clay mineral can be classified into three types i.e. Kaolinite, montmorillonite and illite. The type of clay that has been used in this experiment is Bentonite which is a volcanic in origin and has montmorillonite as a major constituent. Clay has water entrapped within its structure and the amount of water depends on the type of clay mineral being dealt with. One of the major properties of clay that I have tried to exploit in this project is its plastic nature i.e. the ability of the soil to gain resistance against shear failure by sliding as they get into a dry state as opposed to possessing very little or no resistance to the same when they absorb water. Attaining help of various properties of clay, in this project I will try to evaluate the various properties of a mortar cube by mixing a fixed proportion by mass of clay in the same and present my observations

scholarly journals Cracking behaviour of fine-grained soils: from laboratory testing to numerical modelling

2019 ◽  
Vol 92 ◽  
pp. 16004
Author(s):  
Pierre Gerard ◽  
Ian Murray ◽  
Alessandro Tarantino
Keyword(s):  
Effective Stress ◽  
Failure Criterion ◽  
Shear Failure ◽  
Digital Camera ◽  
Failure Criteria ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Desiccation Cracking ◽  
Stress States ◽  
Stress Dependent

Many experimental evidences suggest that desiccation cracks in clay initiate as a result of the mobilization of soil tensile strength. However this mechanical approach disregards the cohesionless and effective stress-dependent behaviour of fine-grained soil. On the other hand recent findings in the literature suggest that effective stress-dependent shear failure criteria would be appropriate to explain the mechanisms of desiccation cracking for tensile total stress states. This work aims at assessing the validity of a shear failure criterion to predict the onset of cracking in clay forms exposed to air drying. Clay forms of various geometries were experimentally subjected to non-uniform hydraulic and mechanical boundary conditions. Time and location for crack initiation are monitored using a digital camera. Cracking experiments are then modelled in a hydro-mechanical framework using an effective-stress shear failure criterion. The comparison of simulations with experimental results for both the time and the location of cracking allows assuming that cracking occurs due to failure in shearing.

Behaviour of compacted fine-grained soil in a brine environment

1984 ◽  
Vol 11 (2) ◽  
pp. 196-203 ◽  
Author(s):  
K. J. D. Ridley ◽  
J. K. Bewtra ◽  
J. A. McCorquodale
Keyword(s):  
Hydraulic Conductivity ◽  
Clay Mineral ◽  
Clay Content ◽  
Montmorillonite Clay ◽  
Engineering Properties ◽  
Solution Composition ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Brine Environment

The hydraulic conductivity and engineering properties of compacted fine-grained soils change with time when exposed to a 30% NaCl brine environment. The hydraulic conductivity of brine was found to be greater than that of water in soils where the dominant clay mineral was montmorillonite, whereas a soil rich in illite and kaolinite was virtually insensitive to variations in solution composition. Increases in brine hydraulic conductivities were most pronounced in soils high in montmorillonite where sodium was the dominant adsorbed ion. They demonstrated the most labile hydraulic conductivities. Fine-grained soils, high in montmorillonite clay content, were prone to alteration in engineering properties when soaked in a 30% NaCl brine. However, brine soaking had little effect on soils rich in illite–kaolinite.

scholarly journals Modeling the Compaction Characteristics of Fine-Grained Soils Blended with Tire-Derived Aggregates

2021 ◽  
Vol 13 (14) ◽  
pp. 7737
Author(s):  
Amin Soltani ◽  
Mahdieh Azimi ◽  
Brendan C. O’Kelly
Keyword(s):  
Energy Levels ◽  
Model Development ◽  
Dry Mass ◽  
Unit Weight ◽  
Power Functions ◽  
Compaction Characteristics ◽  
Practical Applications ◽  
Fine Grained ◽  
Practical Procedure ◽  
Fine Grained Soil

This study aims at modeling the compaction characteristics of fine-grained soils blended with sand-sized (0.075–4.75 mm) recycled tire-derived aggregates (TDAs). Model development and calibration were performed using a large and diverse database of 100 soil–TDA compaction tests (with the TDA-to-soil dry mass ratio ≤ 30%) assembled from the literature. Following a comprehensive statistical analysis, it is demonstrated that the optimum moisture content (OMC) and maximum dry unit weight (MDUW) for soil–TDA blends (across different soil types, TDA particle sizes and compaction energy levels) can be expressed as universal power functions of the OMC and MDUW of the unamended soil, along with the soil to soil–TDA specific gravity ratio. Employing the Bland–Altman analysis, the 95% upper and lower (water content) agreement limits between the predicted and measured OMC values were, respectively, obtained as +1.09% and −1.23%, both of which can be considered negligible for practical applications. For the MDUW predictions, these limits were calculated as +0.67 and −0.71 kN/m3, which (like the OMC) can be deemed acceptable for prediction purposes. Having established the OMC and MDUW of the unamended fine-grained soil, the empirical models proposed in this study offer a practical procedure towards predicting the compaction characteristics of the soil–TDA blends without the hurdles of performing separate laboratory compaction tests, and thus can be employed in practice for preliminary design assessments and/or soil–TDA optimization studies.

scholarly journals Assessment for Thermal Conductivity of Frozen Soil Based on Nonlinear Regression and Support Vector Regression Methods

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Fu-Qing Cui ◽  
Wei Zhang ◽  
Zhi-Yun Liu ◽  
Wei Wang ◽  
Jian-bing Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Support Vector Regression ◽  
Nonlinear Regression ◽  
Prediction Accuracy ◽  
Prediction Models ◽  
Frozen Soil ◽  
Support Vector ◽  
Soil Thermal Conductivity ◽  
Fine Grained ◽  
Fine Grained Soil

The comprehensive understanding of the variation law of soil thermal conductivity is the prerequisite of design and construction of engineering applications in permafrost regions. Compared with the unfrozen soil, the specimen preparation and experimental procedures of frozen soil thermal conductivity testing are more complex and challengeable. In this work, considering for essentially multiphase and porous structural characteristic information reflection of unfrozen soil thermal conductivity, prediction models of frozen soil thermal conductivity using nonlinear regression and Support Vector Regression (SVR) methods have been developed. Thermal conductivity of multiple types of soil samples which are sampled from the Qinghai-Tibet Engineering Corridor (QTEC) are tested by the transient plane source (TPS) method. Correlations of thermal conductivity between unfrozen and frozen soil has been analyzed and recognized. Based on the measurement data of unfrozen soil thermal conductivity, the prediction models of frozen soil thermal conductivity for 7 typical soils in the QTEC are proposed. To further facilitate engineering applications, the prediction models of two soil categories (coarse and fine-grained soil) have also been proposed. The results demonstrate that, compared with nonideal prediction accuracy of using water content and dry density as the fitting parameter, the ternary fitting model has a higher thermal conductivity prediction accuracy for 7 types of frozen soils (more than 98% of the soil specimens’ relative error are within 20%). The SVR model can further improve the frozen soil thermal conductivity prediction accuracy and more than 98% of the soil specimens’ relative error are within 15%. For coarse and fine-grained soil categories, the above two models still have reliable prediction accuracy and determine coefficient (R2) ranges from 0.8 to 0.91, which validates the applicability for small sample soils. This study provides feasible prediction models for frozen soil thermal conductivity and guidelines of the thermal design and freeze-thaw damage prevention for engineering structures in cold regions.

Physical and Mechanical Properties of Fine-Grained Soil in the Zhejiang-Fujian Coastal Area, China

2011 ◽  
Vol 29 (4) ◽  
pp. 333-345 ◽  
Author(s):  
Yuan-Qin Xu ◽  
Pei-Ying Li ◽  
Ping Li ◽  
Le-Jun Liu ◽  
Cheng-Xiao Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Coastal Area ◽  
Physical And Mechanical Properties ◽  
Fine Grained ◽  
Fine Grained Soil

scholarly journals Centrifuge testing of soil–structure interaction effects on cyclic failure potential of fine-grained soil

2021 ◽  
pp. 875529302098197
Author(s):  
Jason M Buenker ◽  
Scott J Brandenberg ◽  
Jonathan P Stewart
Keyword(s):  
Soil Structure ◽  
Interaction Effects ◽  
Soil Structure Interaction ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Structure Interaction ◽  
Fine Grained ◽  
Stiffness Properties ◽  
Fine Grained Soil ◽  
Strip Footings

We describe two experiments performed on a 9-m-radius geotechnical centrifuge to evaluate dynamic soil–structure interaction effects on the cyclic failure potential of fine-grained soil. Each experiment incorporated three different structures with a range of mass and stiffness properties. Structures were founded on strip footings embedded in a thin layer of sand overlying lightly overconsolidated low-plasticity fine-grained soil. Shaking was applied to the base of the model container, consisting of scaled versions of recorded earthquake ground motions, sweep motions, and step waves. Data recorded during testing were processed and published on the platform DesignSafe. We describe the model configuration, sensor information, shaking events, and data processing procedures and present selected processed data to illustrate key model responses and to provide a benchmark for data use.

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