scholarly journals Determination of Secant Moduli of Agbelouve Silty Sand Stabilized with Cement Used as a Roadway Layer in Togo

2019 ◽  
Vol 9 (2) ◽  
pp. 1409-1415
Keyword(s):  
Compressive Strength ◽  
Strain Measurement ◽  
Soil Stabilization ◽  
Rational Method ◽  
Silty Sand ◽  
Secant Modulus ◽  
Strain Modulus ◽  
Proctor Test ◽  
Sand Stabilized

The soil stabilization use is necessary in the presence of lesser quality soils. This stabilization has the effect of modifying the soils properties, in particular the strain modulus. For road dimensioning using rational method, it is necessary to know secant modulus of the soil which is not often done in Togo. In this paper, it is determined the secant modulus at different ages of silty sand stabilized with cement at different rates. For this, specimen of silty sand stabilized with cement at rates of 2.5; 3.5 and 4.5% are subjected to the Modified Proctor test and measurement of compressive strength with strain measurement to estimate the modulus at 7, 28, 60 and 90 days of age. The results show that moduli increase with age and cement rate. From different correlations, we estimate the dimensioning modulus of Agbélouvé silty sand stabilized with cement. These estimated moduli allow saying that the cement rate studied are satisfactory from the modulus viewpoint. This study completes the information on Togolese materials needed for road dimensioning by rational methods.

scholarly journals Unconfined Compressive Strength Characteristics of Overboulder Asbuton and Zeolite Stabilized Soft Soil

2021 ◽  
Vol 7 (1) ◽  
pp. 40-48
Author(s):  
Noor Dhani ◽  
Ahmad Gasruddin ◽  
Hartini Hartini ◽  
La Baride
Keyword(s):  
Compressive Strength ◽  
Soil Stabilization ◽  
Soft Soil ◽  
Pozzolanic Reaction ◽  
Silica Content ◽  
Curing Time ◽  
Natural Pozzolan ◽  
Soil Stabilizer ◽  
Proctor Test ◽  
High Silica

Soft soil was one of the most widely encountered problems in construction, especially for archipelago countries which most of its area was lowland with a high deposit of soft soil. To overcome this problem, soil stabilization was one of the most widely used as a solution. Soil stabilization in general uses chemical substances that are classified as pozzolan material. Pozzolan material uses its capability to strengthen the cohesion of soil grains. Mostly, pozzolan material consists of silica. Overboulder asbuton and zeolite were examples of natural pozzolan material in Indonesia. Both materials have a high silica content. Thus, the author interested to figure out the mechanical behavior of these two substances as a soil stabilizer. This research was a correlating study to the previous paper with the same author which discusses the overboulder asbuton as a soil stabilizer. Overboulder added to the mix is determined as 15%, with varied zeolite percentages applied to examine the differences. The UCT was conducted according to ASTM D-2166 as a parameter. As the standard remolding method, a standard proctor test was conducted to determine the optimum moisture content and the maximum density of each mix. While the UCT specimens were tested at the certain curing time for each composition. The curing time applied was 0, 7, 14, and 28 days. By this curing period, the effective pozzolanic reaction that occurs for each composition could be determined. The result shows that zeolite addition to overboulder asbuton could increase the soil density and increase its compressive strength. It is indicated that overboulder asbuton and zeolite mix could be a proper alternative as a soil stabilizer. Doi: 10.28991/cej-2021-03091635 Full Text: PDF

Determination of Concrete Cube Strength from Used Samples / Určení Krychelné Pevnosti Betonu U Použitých Zkušebních Trámců

2012 ◽  
Vol 12 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Oldřich Sucharda ◽  
David Mikolášek ◽  
Jiří Brožovský
Keyword(s):  
Compressive Strength ◽  
Concrete Beams ◽  
Linear Analysis ◽  
Bending Tests ◽  
Cube Strength ◽  
Non Linear ◽  
Compressive Strength Of Concrete ◽  
Concrete Cube

Abstract This paper deals with the determination of compressive strength of concrete. Cubes, cylinders and re-used test beams were tested. The concrete beams were first subjected to three-point or fourpoint bending tests and then used for determination of the compressive strength of concrete. Some concrete beams were reinforced, while others had no reinforcement. Accuracy of the experiments and calculations was verified in a non-linear analysis.

scholarly journals Machine Learning Approaches for Prediction of the Compressive Strength of Alkali Activated Termite Mound Soil

2021 ◽  
Vol 11 (11) ◽  
pp. 4754
Author(s):  
Assia Aboubakar Mahamat ◽  
Moussa Mahamat Boukar ◽  
Nurudeen Mahmud Ibrahim ◽  
Tido Tiwa Stanislas ◽  
Numfor Linda Bih ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Construction Materials ◽  
Curing Temperature ◽  
Sustainable Construction ◽  
Support Vector ◽  
Learning Approaches ◽  
Artificial Neural Network Ann ◽  
Curing Regime ◽  
Alkali Activated

Earth-based materials have shown promise in the development of ecofriendly and sustainable construction materials. However, their unconventional usage in the construction field makes the estimation of their properties difficult and inaccurate. Often, the determination of their properties is conducted based on a conventional materials procedure. Hence, there is inaccuracy in understanding the properties of the unconventional materials. To obtain more accurate properties, a support vector machine (SVM), artificial neural network (ANN) and linear regression (LR) were used to predict the compressive strength of the alkali-activated termite soil. In this study, factors such as activator concentration, Si/Al, initial curing temperature, water absorption, weight and curing regime were used as input parameters due to their significant effect in the compressive strength. The experimental results depict that SVM outperforms ANN and LR in terms of R2 score and root mean square error (RMSE).

Rapid determination of soil unconfined compressive strength using reflectance spectroscopy

2021 ◽  
Vol 80 (5) ◽  
pp. 3923-3938
Author(s):  
Fatemeh Mousavi ◽  
Ehsan Abdi ◽  
Parviz Fatehi ◽  
Abbas Ghalandarzadeh ◽  
Hossein Ali Bahrami ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Rapid Determination ◽  
Reflectance Spectroscopy

Caracterización de la roca mediante propiedades físicas y su relación con la resistencia a la compresión simple

2021 ◽  
Vol 2 (4) ◽  
pp. 5081-5093
Author(s):  
Patricio Feijoo Calle ◽  
Elizabeth Brito Verdezoto
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Unconfined Compressive Strength ◽  
Approximate Determination ◽  
Practical Application ◽  
Calculation Methodology

En este trabajo se propone una metodología sencilla y de aplicación práctica en campo para la determinación aproximada de la Resistencia a la Compresión Simple (RCS) en rocas, propiedad o característica que es importante en minería, ya que mediante la misma, se ejecutan análisis para la valoración de factores de seguridad y estabilidad y/o posibles sistemas de fortificación en las obras o estructuras mineras, a más de que la caracterización de la RCS es también influyente en el uso de explosivos para la explotación o extracción de materiales de una cantera o mina. Esta estimación se la propone en base a la determinación de las siguientes tres propiedades de la roca, que en esta investigación las denominamos densidad, porosidad y absorción “en mina”. Estas propiedades físicas se las puede obtener de una forma simple, pero metódica y en este trabajo se han ejecutado ensayos sobre un mismo material o roca proveniente de la zona de Cojitambo, provincia del Cañar (Ecuador) y sobre una base de 60 muestras o probetas. Los resultados obtenidos permiten una correlación entre las propiedades antes descritas y la RCS, a más que se ha estructurado una metodología de cálculo para el objetivo planteado.   This work proposes a simple methodology and practical application in the field for the approximate determination of the Unconfined Compressive Strength (UCS) in rocks, property or characteristic that is important in mining, since through it analyzes are carried out to the assessment of security and stability factors and/or possible fortification systems in the works or mining structures, in addition to the characterization of the UCS is also influential in the use of explosives for the exploitation or extraction of materials from a quarry or mine. This estimate is proposed based on the determination of the following three properties of the rock, which in this investigation we call density, porosity and absorption “in mine”. These physical properties can be obtained in a simple, but methodical way and in this work, tests have been carried out on the same material or rock from the Cojitambo area, Cañar province (Ecuador) and on the basis of 60 samples or test tubes. The results obtained allow a correlation between the properties described above and the UCS, in addition to a calculation methodology for the proposed objective.

scholarly journals Preliminary research for identification of bacteria useful in microbially induced calcium carbonate precipitation

2018 ◽  
Vol 44 ◽  
pp. 00115
Author(s):  
Katarzyna Misiołek ◽  
Paweł Popielski ◽  
Katarzyna Affek
Keyword(s):  
Calcium Carbonate ◽  
Soil Stabilization ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation ◽  
Construction Sites ◽  
Calcite Precipitation ◽  
Strength Parameters ◽  
Gram Staining ◽  
Identification Of Bacteria

MICP (Microbially Induced Calcite Precipitation) is a new biological method in soil stabilization. This cheap and eco-friendly technique improves strength parameters of the ground such as shear strength and decreases the permeability of gravelly and sandy soil. There are variety of microorganisms that can be used in calcite precipitation. The most popular method is precipitation of calcium carbonate by bacteria. The main purpose of the article is to present the results from Gram staining of bacteria isolated from construction sites, which is the first step of their identification. Gram’s method allows to find out which morphological groups of bacteria are adapted to conditions present in soil from construction sites and therefore are potentially able to produce calcite. The article describes the methodology of isolation, staining and determination of morphological types of bacteria.

Influence of Sample Thickness and Capping on Characterization of Bedding Mortars from Historic Masonries by Double Punch Test (DPT)

2014 ◽  
Vol 624 ◽  
pp. 322-329 ◽  
Author(s):  
Enrico Sassoni ◽  
Elisa Franzoni ◽  
Claudio Mazzotti
Keyword(s):  
Compressive Strength ◽  
Poor Quality ◽  
Sample Thickness ◽  
Mortar Sample ◽  
Hydraulic Lime ◽  
Punch Test ◽  
Natural Hydraulic Lime ◽  
Wide Range ◽  
Surface Capping

For determination of compressive strength of bedding mortar used in historic masonries, a promising moderately-destructive technique is double punch test (DPT). DPT consists of loading prismatic samples of mortar (about 4×4×1 cm3) by means of two circular steel platens (typically 2 cm diameter) and then calculating mortar compressive strength as the ratio of the failure load to the cross section of the circular platens. In this study, the influence of mortar sample thickness and mortar sample capping on the reliability of results obtained by DPT was systematically investigated. The influence of sample thickness was assessed by comparing DPT results obtained for samples with 5, 10, 15 and 20 mm thickness with compressive strength determined by testing reference 4 cm-side cubes. Different mortars were considered (cement, lime-cement, natural hydraulic lime), in order to investigate a wide range of mortar mechanical characteristics. The influence of surface capping was evaluated on a lime-cement mortar by comparing compressive strength determined on reference cubes with strength obtained by DPT on proper samples, without capping and after capping with rubber, gypsum and cement. The results of the study indicate that sample thickness substantially influences mortar compressive strength determined by DPT, which may vary by up to three times depending on sample thickness. A good estimation of the actual mortar compressive strength was obtained when samples with thickness similar to the loading platens diameter were tested, which suggests that choosing the size of the loading platens for DPT based on the thickness of mortar joints under investigation may be an effective way for obtaining reliable estimations. As for the influence of surface capping, in those cases where no mortar sample regularization is possible, because of the poor quality of the mortar, the results of the study indicate that sample capping actually seems necessary in order to avoid significant underestimations of mortar compressive strength. Considering the higher practicality offered by gypsum with respect to rapid-setting cement for surface capping, the use of gypsum seems preferable.

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