• Title/Summary/Keyword: tensile strength

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A study on direct tensile strength of cement soil (시멘트 혼합토의 인장강도에 관한 연구)

  • Kim, Chang-Woo;Park, Sung-Sik;Choi, Hyun-Seok
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.584-594
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    • 2010
  • It is difficult to prepare a specimen for directly testing a tensile strength of soils. Therefore, a tensile strength of soils has been measured indirectly. In this study, a mold and sample preparation tool for directly testing a tensile strength of soils has been developed and a tensile strength of weakly cemented sand was measured by using such device. A compressive strength of the cemented sand was also measured and its value was 30 times greater than its tensile strength.

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Effect of ground granulated blast furnace slag on time-dependent tensile strength of concrete

  • Shariq, M.;Prasad, J.
    • Computers and Concrete
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    • v.23 no.2
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    • pp.133-143
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    • 2019
  • The paper presents the experimental investigations into the effect of ground granulated blast furnace slag (GGBFS) on the time-dependent tensile strength of concrete. The splitting and flexural tensile strength of concrete was determined at the ages of 3, 7, 28, 56, 90, 150 and 180 days using the cylindrical and prism specimens respectively for plain and GGBFS concrete. The amount of cement replacement by GGBFS was 0%, 40% and 60% on the weight basis. The maximum curing age was kept as 28 days. The results showed that the splitting and flexural tensile strength of concrete containing GGBFS has been found lower than the plain concrete at all ages and for all mixes. The tensile strength of 40 percent replacement has been found higher than the 60 percent at all ages and for all mixes. The rate of gain of splitting and flexural tensile strength of 40 percent GGBFS concrete is found higher than the plain concrete and 60 percent GGBFS concrete at the ages varying from 28 to 180 days. The experimental results of time-dependent tensile strength of concrete are compared with the available models. New models for the prediction of time-dependent splitting and flexural tensile strength of concrete containing GGBFS are proposed. The present experimental and analytical study will be helpful for the designers to know the time-dependent tensile properties of GGBFS concrete to meet the design requirements of liquid retaining reinforced and pre-stressed concrete structures.

Laboratory and Meta Analysis for 9% NI Steel of Liquified Natural Gas Carrier (LNG 저장 탱크 운반선 9% Ni Steel의 용접성에 대한 실험분석과 메타분석 연구)

  • Park, Sang Heup;Ahn, Duck Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.670-677
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    • 2016
  • Laboratory and meta-analyses were done for 9% NI Steel for use in a liquefied natural gas carrier. The meta-analysis is based on a previous study. The laboratory analysis examines the effects of a single pass and multiple passes on the tensile strength through an impulse-response test. The tensile strength increased from pass one to pass three and decreased from pass four to pass ten. The pass and multi-pass welding had a positive effect on the tensile strength. Lastly, the welding and tensile time had a positive effect on the tensile strength.

Study on the mechanical Properties of Carbon Fiber Sheet (탄소섬유쉬트의 재료 역학적 특성에 관한 연구)

  • 이한승
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.803-808
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    • 1998
  • As carbon fiber is a light-weight materials, high tensile strength and durability compared with rebar, the retrofitting method for RC structures using carbon fiber sheet (CFS) must be use widely. In this paper, the tensile strength test for carbon fiber sheet variable of CF's weight and elastic modulus to evaluate the design tensile strength of carbon fiber sheet which is needed for the strengthening design of CFS and the calculation of strengthening effect. As a result, the design tensile strength of CFS can be calculate using the effect coefficient of strengthening(α) of CFS, the average tensile strength of CFS and the standard deviation of CFS(equation 5)

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Characterization of Tensile Strength of Anisotropic Rock Using the Indirect Tensile Strength Test (간접인장강도시험을 통한 이방성 암석의 인장강도 특성)

  • 김영수;정성관;최정호
    • Journal of the Korean Geotechnical Society
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    • v.18 no.5
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    • pp.133-141
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    • 2002
  • Isotropic rock and anisotropic rock have different tensile strength which has the greatest influence on rock failure. In this study, elastic modulus of anisotropic rock is obtained through uniaxial compression test, and tensile strength and tension failure behavior are analyzed through indirect tensile strength test. Stress concentration factor of a specimen at the center is obtained from anisotropic elastic modulus and strain by indirect tensile strength test. Theoretical solutions for tensile strength of isotropic and anisotropic rock are compared. Stress concentration factor of anisotropic rock is either higher or lower than isotropic rock depending on the inclination angle of bedding plane. The use of stress concentration factor of isotropic rock resulted in overestimation or underestimation of tensile strength.

Effect of Fiber Orientation on the Tensile Strength in Twisted Yarn Composites (Twisted Yarn 복합재료에서 인장강도에 미치는 섬유배향의 영향)

  • Lee, Dong-Ki;Sim, Jae-Ki;Kim, Hyuk;Kim, Jin-Woo;Lee, Jung-Ju;Lee, Ha-Wook
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.422-425
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    • 2003
  • Investigated whether fiber orientation distribution of twisted yarn composites and the fiber content are 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength and some correlation. Tensile strength of 0$^{\circ}$ directions of twisted yarn composites increased changelessly being proportional the fiber content and fiber orientation function get into anisotropic in isotropic. But, tensile strength ratio by separation of fiber filament of 90$^{\circ}$ directions tensile strength decreased when tensile load is imposed for width direction of reinforcement fiber. 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength ratio value of a twisted yarn composites not receive almost effect of the fiber content of fiber orientation function J = 0.4 lows. Although do, 20 wt% of the fiber content is high about 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength ratio about 1.6~2 than 10 wt% from J = 0.4. Therefore. could know that effect of the fiber content is dominate.

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Estimation of tensile strength of ultramafic rocks using indirect approaches

  • Diamantis, Konstantinos
    • Geomechanics and Engineering
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    • v.17 no.3
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    • pp.261-270
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    • 2019
  • Because the estimation of the tensile strength is very important in any geotechnical project, many attempts have been made to determine. But the immediate determination of the tensile strength is usually difficult owing to well-shaped specimens, time-consuming, expensive and sometimes unreliable. In this study, engineering properties of several ultramafic rock samples were measured to assess the correlations between the Brazilian Tensile Strength (BTS) and degree of serpentinization, physical, dynamic and mechanical characteristics. For this purpose, a comprehensive laboratory testing program was conducted after collecting thirty-two peridotite and fifty-one serpentinite rock samples, taken from central Greece, in accordance with ASTM and ISRM standards. In addition, a representative number of them were subjected to petrographic studies and the obtained results were statistically described and analysed. Simple and multiple regression analyses were used to investigate the relationships between the Brazilian Tensile Strength and the other measured properties. Thus, empirical equations were developed and they showed that all of the properties are well correlated with Brazilian Tensile Strength. The curves with the $45^{\circ}$ line (y = x) were extracted for evaluating the validity degree of concluded empirical equations which approved approximately close relationships between Brazilian Tensile Strength and the measured properties.

A Study on Double - Punch Test for Tensile Strength of Concrete (Double-Punch Test에 의한 콘크리트의 인장강도 시험에 관한 연구)

  • 이우종;고재군
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.2
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    • pp.82-94
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    • 1988
  • The purpose of this study is to introduce the Double Punch test method which is an indirect testing method of tensile strength of concrete, and to compare with the tensile strength of concrete as determined by the split-cylinder test, a practical method for performing the Double Punch test to obtain the tensile strength of concrete is proposed and recommended for general use. In this study, the dimensions of cylindrical specimens used in the Double-Punch test were 15X30cm, 15X15cm, 10${\times}$(20cm, and 5${\times}$l0cm, and in the split-cylinder test were 15${\times}$(30cm, 15${\times}$(15cm, and 10${\times}$(20cm. And the diameters of loading punches used in the Double-Punch test were 1.5cm, 2.5cm, and 3.5 cm. The results obtained from tests are summarized as follows ; 1. In the split-cylinder test, the tensile strength of concrete by the linear elasticity theory is similar to that of plasticity theory. 2. Both split-cylinder test and Double-Punch test, tensile strength of concrete is increased with decreasing specimen size. This tendency is identical when the ratio of specimen diameter to height is 1: 2, but that tendency is quite different when the ratio is 1: 3. In the Double-Punch test, if specimen size is constant, by increasing the punch size, tensile strength of concrete is increased, too. 4. Using a 15 ${\times}$( 15 cm cylinder specimen and 3.5 cm diameter punch in the Double Punch test would give the most uniform and consistent result in tensile strength, and the result showed a gQod correlation with splitting tensile strength from 15 x 30cm specimen. 5. In order to obtain satisfactory results and to nuninuze variability, it is proposed that specimens of 15 cm in diameter and 15 cm in height with two 3.5 cm diameter punches should be used. It seems, therefore, reasonable tt) take f't=0.0024 P(kg / cm$^2$) as a working formula for computing the tensile strength in the Double Punch test for concrete.

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Evaluation of tensile strength of surgical synthetic absorbable suture materials: an in vitro study

  • Khiste, Sujeet Vinayak;Ranganath, V.;Nichani, Ashish Sham
    • Journal of Periodontal and Implant Science
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    • v.43 no.3
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    • pp.130-135
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    • 2013
  • Purpose: The purpose of this study was to evaluate the tensile strength of surgical synthetic absorbable sutures over a period of 14 days under simulated oral conditions. Methods: Three suture materials (polyglycolic acid [PGA], polyglactin [PG] 910, and poly (glycolide-co-${\epsilon}$-caprolactone) [PGC]) were used in 4-0 and 5-0 gauges. 210 suture samples (35 of each material and gauge) were used. All of the samples were tested preimmersion and 1 hour and 1, 3, 7, 10, and 14 days postimmersion. The tensile strength of each suture material and gauge was assessed. The point of breakage and the resorption pattern of the sutures were also assessed. Results: During the first 24 hours of immersion, all 4-0 and 5-0 samples of PGA, PG 910, and PGC maintained their initial tensile strength. At baseline (preimmersion), there was a statistically significant (P<0.001) difference in the tensile strengths between the 4-0 and 5-0 gauge of PGA, PG 910, and PGC. PGA 4-0 showed the highest tensile strength until day 10. At 7 days, all the 4-0 sutures of the three materials had maintained their tensile strength with PGA 4-0 having significantly greater (P=0.003) tensile strength compared to PG. Conclusions: 4-0 sutures are stronger and have greater tensile strength than 5-0 sutures. The PGA 4-0 suture showed the highest tensile strength at the end of day 10.

Numerical simulation of compressive to tensile load conversion for determining the tensile strength of ultra-high performance concrete

  • Haeri, Hadi;Mirshekari, Nader;Sarfarazi, Vahab;Marji, Mohammad Fatehi
    • Smart Structures and Systems
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    • v.26 no.5
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    • pp.605-617
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    • 2020
  • In this study, the experimental tests for the direct tensile strength measurement of Ultra-High Performance Concrete (UHPC) were numerically modeled by using the discrete element method (circle type element) and Finite Element Method (FEM). The experimental tests used for the laboratory tensile strength measurement is the Compressive-to-Tensile Load Conversion (CTLC) device. In this paper, the failure process including the cracks initiation, propagation and coalescence studied and then the direct tensile strength of the UHPC specimens measured by the novel apparatus i.e., CTLC device. For this purpose, the UHPC member (each containing a central hole) prepared, and situated in the CTLC device which in turn placed in the universal testing machine. The direct tensile strength of the member is measured due to the direct tensile stress which is applied to this specimen by the CTLC device. This novel device transferring the applied compressive load to that of the tensile during the testing process. The UHPC beam specimen of size 150 × 60 × 190 mm and internal hole of 75 × 60 mm was used in this study. The rate of the applied compressive load to CTLC device through the universal testing machine was 0.02 MPa/s. The direct tensile strength of UHPC was found using a new formula based on the present analyses. The numerical simulation given in this study gives the tensile strength and failure behavior of the UHPC very close to those obtained experimentally by the CTLC device implemented in the universal testing machine. The percent variation between experimental results and numerical results was found as nearly 2%. PFC2D simulations of the direct tensile strength measuring specimen and ABAQUS simulation of the tested CTLC specimens both demonstrate the validity and capability of the proposed testing procedure for the direct tensile strength measurement of UHPC specimens.