scholarly journals Petrographic study and its implication to the uniaxial strength of weathered volcanic rocks from tawau, sabah

Author(s):  
Hennie Fitria W. Soehady Erfen ◽  
Baba Musta

This paper discussed the petrographic study and its effect to the uniaxial strength of weathered volcanic rocks from Tawau, Sabah, Malaysia. The volcanic rock consists of associated dacite, andesite and basalt rocks with the age of Pliocene to Quaternary. In this study the Murphy (1985) classification were used determine the weathering grade of volcanic rocks. The uniaxial strength value were used the Point Load Test and Uniaxial Compressive Strength test. The microstructures and identification of altered minerals were analysed using scanning electron microscope (SEM) and polarized microscope, respectively. The result of analysis indicated that the uniaxial strength of volcanic rocks decreased with the degree of weathering grades where the uniaxial strength decreased from 122.2 to 15.8 MPa for dacite, 143.4 to 10.1 MPa for basalt and 181.2 to 26.8 MPa for andesite. This result is due to the different percentages of quartz and feldspar minerals in the rock samples as well as formation of secondary minerals in weathered rocks.  Microstructures study showed the appearance of micro fractures with narrow apertures in the minerals also influenced the uniaxial strength of the rocks.________________________________________GRAPHICAL ABSTRACT

2018 ◽  
Vol 203 ◽  
pp. 06011
Author(s):  
Saeed Ahmad ◽  
Ayub Elahi ◽  
Hafiz Waheed Iqbal ◽  
Faiza Mehmood

The objective of this research work was to determine the effect of fiber cocktail on mechanical properties of concrete. Three types of fibers were used namely monofilament polypropylene fiber, steel fiber and glass fiber. Steel and glass fiber were incorporated in concrete at different dosages while the content of Polypropylene fiber was kept constant. For this purpose, cubes (150×150×150mm) and prisms (101×101×508mm) were casted for compressive strength test on cubes and Two-Point load test on prisms. Eighteen different mixes were prepared such as control mix, single fiber concrete, double hybrid concrete and triple hybrid concrete. It was observed that both compressive and flexural strength increased with addition of single, double and triple fibers. However, the strengths of triple hybrid concrete were observed to be lesser as compared to single and double hybrid concrete.


Author(s):  
Edward Dinoy ◽  
Yohanes Gilbert Tampaty ◽  
Imelda Srilestari Mabuat ◽  
Joseph Alexon Sutiray Dwene

The compressive strength test is one of the technical properties or compressive strength tests that are commonly used in rock mechanics to determine the collapse point or the elasticity of rock against maximum pressure. The rock collapse point is a measure of the strength of the rock itself when the rock is no longer able to maintain its elastic properties. The purpose of this test is to find out how long the rock maintains its strength or elasticity properties when pressure is applied, and to find out the difference between the strength of compact rock and rock that has fractures when pressure is applied. Rocks that have fractures will break more easily or quickly when pressure is applied compared to compact rocks. This analysis is carried out by comparing the rock strength of each sample, both those that have fractures and compact rocks. To find out these differences, laboratory testing was carried out. The test results show the value (compressive strength test 57.76 MPa), (elastic modulus 5250.000MPa), (Poisson ratio 0.05) and the average value of rock mechanical properties test (axial 0.91), (lateral-0.279), and (volumetric 0.252) . Based on the test results above, it shows that rocks that have fractures will break more easily when pressure is applied, compared to compact rocks that have a long time in the uniaxial compressive strength test.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1871-1874
Author(s):  
Xiao Fei Wang ◽  
Yang Ping Wang ◽  
Li Cheng Wu

The same batch reactive powder concrete specimens were obtained with same raw materials and curing process, uniaxial compressive strength test had been done on the specimens after hot water curing placed in laboratory for seven days , three months and three years. The test results showed that seven-day strength and three-month strength of plain reactive powder concrete after hot water curing are almost equal. Strength of plain reactive powder concrete has not degradation within three months after hot water curing. While strength of plain reactive powder appears serious degradation phenomenon after placed in Laboratory for three years. Comparing uniaxial compressive strength test results of plain reactive powder concrete at three-month with three-year after hot water curing ,we find that strength of plain reactive concrete at three-year decrease about 27 percent than the strength of plain reactive powder concrete placed at laboratory for three months, and elasticity modulus increases about 71 percent, axial peak strain decrease about 62 percent respectively .With the passage of time, plain reactive powder concrete appears more Brittle Features and less toughness.


Minerva ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 11-22
Author(s):  
Ernesto Patricio Feijoo Calle ◽  
Paúl Andrés Almache Rodríguez

The objective of this work is to establish a relationship between the cutting time in rocks, determining a speed and the point load strength index test, Is (50), to characterize the rock in terms of resistance and avoid sending samples to laboratories. As a first stage, on andesite samples, 5 x 5 x 10 cm test tubes were made. After the elaboration they were subjected to cutting, using an electric floor cutter and the time was evaluated. This cut was made in a transversal way and two parts were obtained, one of them with dimensions 5 x 5 x 5 cm, approximately. In a third stage, the point load strength test was carried out in a press built for this purpose. Finally, the cutting speeds were correlated with the point load test values and only when rock samples do not pigeonhole on the proposed relationship, send them to the laboratory. Keywords: Mining fortification, uniaxial compressive strength, rock cutting, point load strength test index. References [1]P. Feijoo, R. Aucay, D. Ordoñez, "Aplicación del esclerómetro para la determinación de resistencia a compresión de rocas", presentado en el IV Congreso Internacional de Minería y Metalúrgia (MINEMETAL), Varadero, Cuba, 2018. [2]P. Feijoo y M. Román, «Correlación entre la Deformación y la Resistencia a la Compresión de rocas», uct, vol. 23, n.º 91, p. 6, may. 2019. [3]P. Feijoo, A. Bravo, N. Escandón, "Aplicación “UDAFORMIN” para la determinación del tipo de fortificación minera", presentado en el XII Congreso Iberoamericano de Computación para el Desarrollo (COMPDES), San Salvador, El Salvador, 2019. [4]P. Feijoo y C. Iñiguez, «Corte en las Rocas y su Relación con la Resistencia a Comprensión Simple», RISTI, n.º E 30, p. 59-67, jun. 2020. [5]P. Feijoo y J. Padrón, «La Resistividad de Rocas y su Relación con la Resistencia a Comprensión Simple en Mina», UCT, vol. 24, n.º 99, pp. 61-67, abr. 2020. [6]M. González. El terreno. Ediciones UPC. Barcelona. España, 2001. [7]E. Besoain. Mineralogía de Suelos. Turrialba: Instituto Interamericano de Ciencias Agrícolas de la OEA, 1970. [8]P. Feijoo, A. Flores, B. Feijoo, "The Concept of the Granulometric Area and Its Relation with the Resistance to the Simple Compression of Rocks", presentado en la 7th International Engineering, Sciences and Technology Conference (IESTEC), Panamá, Panamá, 2019, pp. 52-56, doi: 10.1109/IESTEC46403.2019.00018. [9]F. Blyth. Geología para Ingenieros. Cecsa. México D. F. México, 2003. [10] E. Tarbuck & F. Lutgens. Ciencias de la Tierra: Una introducción a la Geología Física. Pearson. Madrid. España, 2005. [11]L. Suarez del Rio, A. Rodríguez, L. Calleja, V. Ruiz de Argandoña, «El corte de rocas ornamentales con discos diamantados: influencia de los factores propios del sistema de corte», CSIC, vol. 48, n.º 250, pp. 53-59, abr-mayjun 1998. [12]Universidad Politécnica de Madrid. Explotaciones de Roca Ornamental. Diseño de explotaciones y selección de maquinaria y equipos. UPM. Madrid. España, 2007. [13]Catalog, Covington, (2019). LAPIDARY & GLASS MACHINERY, USA. Retrieved from https://covington-engineering.com/content/pdf/Covington-Catalog.pdf. [14]D. Burbano, T. García, «Estimación empírica de la resistencia a compresión simple a partir del ensayo de carga puntual en rocas anisótropas (esquistos y pizarras)», FIGEMPA, vol.1, n.º 2, pp. 13-16, dic. 2016. [15]P. Ramírez, L. de la Cuadra, R. Lain, E. Grigalbo. Mecánica de rocas aplicada a la minería metálica subterránea. Instituto Geológico Minero. Madrid. España, 1984. [16]P. Cordero, "Manual de prácticas de laboratorio de Mecánica de Rocas (Parte I)" tesis, Universidad Nacional Autónoma de México, México D.F., México, 2019. [17]L. González de Vallejo, M. Ferrer. Manual de campo para la descripción y caracterización de macizos rocosos en afloramientos. Instituto Geológico y Minero de España. Madrid. España, 2007. [18]P. Pohjanpera, T. Wanne, E., Johansson. Point Load Test Results From Olkiluoto Area Borehole Cores. Posiva. Finlandia, 2005. [19]P. Ramírez, L. Alejano. Mecánica de rocas: fundamentos e ingeniería de taludes. Universidad Politécnica de Madrid. Madrid. España, 2004. [20]M. Navarrete, W. Martínez, E. Alonso, C. Lara, A. Bedolla, H. Chávez, D. Delgado, J. Arteaga. «Caracterización de propiedades físico-mecánicas de rocas ígneas utilizadas en obras de infraestructura», ALCONPANT, vol. 3, n.º 2, pp. 133-143, ago. 2013. [21]P. Feijoo, "Manual de mecánica de rocas y estabilidad de túneles y taludes" tesis, Universidad del Azuay, Cuenca, Ecuador, 1997.    


2019 ◽  
Vol 9 (1) ◽  
pp. 39-46
Author(s):  
Halauddin Halauddin

Research on the effect of the addition of rice husk and poly vinyl acetate emulsion polymer co acrylic (PVA) on clay have been conducted to see the strength of brick. Calculation of strength compared to brick by rice husks and polymer emulsion and given rice husk without any emulsion polymer. Provision of rice husk to batter was fixed at 9:1, while the provision of PVA polymer mixture for each batter with varying percentage are 1%-7%. Based on the results of the research, showed that: uniaxial compressive strength test resultsbricks to mix rice husk without PVA emulsion polymer was 28,7kg/cm2(L0), compressive strength test results bricks to mix rice husk with PVA emulsion polymer to a mixture of 1%-7%, respectively: (PVA 1% of 28,7 kg/cm2 (L1);(PVA 2% of 28,7 kg/cm2 (L2); (PVA 3% of 28,7 kg/cm2 (L3); (PVA 4% of 28,7 kg/cm2 (L4); (PVA 5% of 28,7 kg/cm2  (L5); (PVA 6% of 28,7 kg/cm2 (L6); and (PVA 7% of 28,7 kg/cm2 (L7). From the above results show that the compressive strength test results bricks to mix rice husk with PVA emulsion polymer mix increased from 1% to 3% mix, while starting from a mixture of 4% to 7% of the compressive strength of bricks dropped dramatically. The addition of PVA 3% of additions that the most effective way to improve the compressive strength of the bricks with compressive strength reached 53,5 kg/cm2, or increase of 46,4% from a brick with a mixture ofrice husk.


2014 ◽  
Vol 580-583 ◽  
pp. 48-51
Author(s):  
Shi Yin Zhang

Use two kinds of soil, processes the uniaxial compressive strength test under the condition of pressure and zero pressure freeze, concludes different test results. That is the uniaxial compressive strength of frozen soil under pressure is higher than that without pressure, and laboratory test data as the basis for the design of the temporary support is relatively safe.


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