Direct tensile tests on particulate agglomerates for the determination of tensile strength and interparticle bond forces

2017 ◽  
Vol 28 (9) ◽  
pp. 2177-2185 ◽  
Author(s):  
Tobias Wollborn ◽  
Marcelo F. Schwed ◽  
Udo Fritsching
Keyword(s):  
Tensile Strength ◽  
Tensile Tests ◽  
Interparticle Bond ◽  
Direct Tensile

Comparative study of tensile tests based on Hopkinson bar for recycled aggregate concrete

2018 ◽  
Vol 10 (1) ◽  
pp. 26-53
Author(s):  
Junzhou Duan ◽  
Yubin Lu ◽  
Shu Zhang ◽  
Xiquan Jiang
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Coarse Aggregate ◽  
Tensile Tests ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Dynamic Tensile Strength ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Direct Tensile

To comparatively study the tensile properties and fracture patterns of recycled aggregate concrete with various replacement percentages (i.e. 0%, 25%, 50%, 75%, and 100%) of recycled coarse aggregate, the dynamic direct tensile tests, splitting tests, and spalling tests of recycled aggregate concrete in the strain-rate range of 100–102 s−1 were carried out using large diameter (75 mm) split Hopkinson tensile bar and pressure bar. Test results show that for recycled aggregate concrete, the quasi-static direct tensile strength is more marvelous than its quasi-static splitting strength. When recycled coarse aggregate replacement percentage is 0%–75%, the replacement percentage impact minimally on the quasi-static tensile strength of recycled aggregate concrete. In dynamic tensile tests, there exists apparent difference between the dynamic direct tensile strength and dynamic splitting. The dynamic tensile strength of recycled aggregate concrete increases with the increase of average strain-rate in all three kinds of tests. The average strain-rate affects the damage form of recycled aggregate concrete, which indicates that the recycled aggregate concrete has obvious rate sensitivity. There shows no obvious regularity between the dynamic tensile strength and the recycled coarse aggregate replacement percentage. And the indirect tensile strength calculation method used in this article offers the theoretical basis for the engineering application of recycled aggregate concrete.

Septum morphology and bathymetry in cephalopods

Paleobiology ◽  
1980 ◽  
Vol 6 (1) ◽  
pp. 48-50 ◽  
Author(s):  
Gerd E. G. Westermann ◽  
Peter Ward
Keyword(s):  
Tensile Strength ◽  
Structural Damage ◽  
Original Data ◽  
Tensile Tests ◽  
The Philippines ◽  
Nautilus Pompilius ◽  
Septal Thickness ◽  
Pressure Tests ◽  
Direct Tensile ◽  
Septal Curvature

Nautilus pompilius at Fiji lives abundantly to about 600 m depth while the shell implodes between 730–900 m when sunk in a cage. From this, and the average parameters of the septum, its tensile strength is calculated to 110–140 MPa. This is markedly higher than the latest value from direct tensile tests (78 MPa). In recent pressure tests by Saunders and Wehman with dry shells from the Philippines, implosion occurred at pressure equivalents to 310–680 m depth, without significant correlation with septal thickness. We attribute this excessive range and non-correlation to structural damage by postnecrotic processes. The recalculated tensile strength from their original data is 56–137 MPa; the higher values are compatible with our values for septal nacre of Nautilus and Spirula (c. 155 MPa). Septal curvature and thickness in orthocones thus remain useful guides to bathymetry.

Direct Tensile Strength Measurement of Concrete

2011 ◽  
Vol 117-119 ◽  
pp. 9-14 ◽  
Author(s):  
Mohammad Iqbal Khan
Keyword(s):  
Tensile Strength ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Strength Measurement ◽  
Ongoing Research ◽  
Tensile Strength Test ◽  
Direct Tensile ◽  
Indirect Tests ◽  
Direct Tensile Strength

The evaluation of the tensile strength and determination of the tensile stress-strain curve using indirect tests becomes approximate hence there is a necessity for exploring direct tensile strength measurement. This investigation is part of ongoing research on the development of direct tensile strength measurement. In this paper direct tensile strength test has been proposed and the results obtained have been compared with compressive strength and flexural strength. It has been found that results obtained are well comparable and relationships are similar to that proposed in earlier findings.

Stress and strain measurements in static tensile tests

2012 ◽  
Vol 19 (3) ◽  
pp. 531-540 ◽  
Author(s):  
Stanisław Adamczak ◽  
Jerzy Bochnia ◽  
Czesław Kundera
Keyword(s):  
Tensile Strength ◽  
Measurement Errors ◽  
Room Temperature ◽  
Tensile Tests ◽  
Stress And Strain ◽  
Accuracy Of Measurements ◽  
Strength Tests ◽  
Static Tensile ◽  
Limiting Errors

Abstract The paper deals with the accuracy of measurements of strains (elongation and necking) and stresses (tensile strength) in static room-temperature tensile strength tests. We present methods for calculating measurement errors and uncertainties, and discuss the determination of the limiting errors of the quantities measured for circular and rectangular specimens, which is illustrated with examples.

scholarly journals Long-Term Bonding and Tensile Strengths of Carbon Textile Reinforced Mortar

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4485
Author(s):  
Kira Heins ◽  
Magdalena Kimm ◽  
Lea Olbrueck ◽  
Matthias May ◽  
Thomas Gries ◽  
...  
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Accelerated Aging ◽  
Tensile Tests ◽  
The Other ◽  
Other Hand ◽  
Direct Tensile ◽  
Moisture Conditions ◽  
Textile Reinforced Mortar

This paper deals with the long-term bonding and tensile strengths of textile reinforced mortar (TRM) exposed to harsh environments. The objective of this study was to investigate the long-term bonding and tensile strengths of carbon TRM by an accelerated aging method. Moisture, high temperature, and freezing–thaw cycles were considered to simulate harsh environmental conditions. Grid-type textiles were surface coated to improve the bond strength with the mortar matrix. A total of 130 TRM specimens for the bonding test were fabricated and conditioned for a prolonged time up to 180 days at varying moisture conditions and temperatures. The long-term bonding strength of TRM was evaluated by a series of bonding tests. On the other hand, a total of 96 TRM specimens were fabricated and conditioned at freezing–thaw conditions and elevated temperature. The long-term tensile strength of TRM was evaluated by a series of direct tensile tests. The results of the bonding test indicated that TRM was significantly degraded by moisture. On the other hand, the influence of the freezing–thaw conditions and high temperature on the tensile strength of the TRM was insignificant.

Resistance of Polyethylene Geonets against Thermo-Oxidation

2012 ◽  
Vol 730-732 ◽  
pp. 480-485
Author(s):  
José Ricardo Carneiro ◽  
Paulo Joaquim Almeida ◽  
M. Lurdes Lopes
Keyword(s):  
Tensile Strength ◽  
High Density Polyethylene ◽  
Research Team ◽  
Maximum Load ◽  
Tensile Tests ◽  
High Density ◽  
New Method

This paper studies the resistance of two high-density polyethylene geonets (manufactured with or without the additive Tinuvin 783) against thermo-oxidation. The materials were exposed to thermo-oxidation by two methods: oven-ageing tests at 100 °C and a new method developed by our research team. The damages suffered by the geonets were evaluated by tensile tests (determination of tensile strength, elongation at maximum load and toughness). Finally, the results obtained in the oven-ageing tests were compared with the results obtained by the new method.

Influence of Different Loading Modes on Rock Tensile Strength

2007 ◽  
Vol 353-358 ◽  
pp. 2553-2556 ◽  
Author(s):  
Ru Wang ◽  
Chun An Tang ◽  
Shu Hong Wang ◽  
Zhi Yuan Wang ◽  
Tian Hui Ma
Keyword(s):  
Tensile Strength ◽  
Process Analysis ◽  
Failure Process ◽  
Tensile Tests ◽  
Loading Mode ◽  
Splitting Test ◽  
Stress States ◽  
Loading Modes ◽  
Direct Tensile ◽  
Direct Tensile Test

A typical mechanical character of rock is that the tensile strength is far less than the compressive strength. Meanwhile, the test data of tensile strength is very dispersive. Because the direct tensile tests always result in failure due to the difficulty in clamping the rock sample, the splitting test is used to determine the tensile strength of rock. There are four kinds of loading modes in the splitting test in actual laboratory test: angle pad splitting, round pad splitting, aclinic loading platen splitting, arc loading platen splitting. In this paper, the direct tensile test, the splitting test and the influence of different loading modes on rock tensile strength were studied. In order to study the stress distribution, the progressive splitting failure process was numerically modeled under the four kinds of loading cases by the Realistic Failure Process Analysis code (RFPA2D). Results show that the stress states under angle pad splitting, round pad splitting are similar to the stress states under diametrical compressive state. Regarding that the round pad splitting test is easy to implement, and its numerical results are also stable relatively, the round pad loading mode was suggested to be adopted.

Direct Tensile Strength of Lightweight Concrete Using Polypropylene Coarse Aggregate Coated with Sand

2018 ◽  
Vol 789 ◽  
pp. 131-136
Author(s):  
Purnomo Heru ◽  
Andhika Rizki Yuandry ◽  
Elly Tjahjono
Keyword(s):  
Tensile Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Tensile Tests ◽  
Fine Aggregate ◽  
River Sand ◽  
Coarse Aggregates ◽  
Stress Strain Relation ◽  
Direct Tensile ◽  
Direct Tensile Strength

Plastic waste used as coarse aggregates in structural concrete is part of efforts to minimizeenvironmental pollution. It can provide lightweight concrete but with a lower strength compared tonormal concrete. Accordingly, an experimental study of 12 concrete specimens using wastepolypropylene coarse aggregates coated with sand was carried out. Direct tensile tests were conductedto cylinder concrete specimens having diameter of 10 cm and depth of 20 cm respectively. Threemixtures of sand coated polypropylene coarse plastic aggregate, river sand as fine aggregate, waterand Portland Composite Cement with a water-cement ratio of 0.286 were conducted. The massproportion of cement and sand are the same but the mass of plastic coarse aggregates coated withsand is specific for each mixture. Direct tensile strength of the specimens in general shows that highertensile strength is found for specimens having higher compressive strength. From the test results, amodel of direct tensile stress-strain relation is proposed. Finally the direct tensile strength forlightweight concrete using polypropylene coarse aggregate coated with sand is found to be lower thanthe direct tensile strength for normal concrete.

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