scholarly journals Experimental Research on Compression Properties of Cement Asphalt Mortar due to Drying and Wetting Cycle

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ping Wang ◽  
Hao Xu ◽  
Rong Chen ◽  
Jingmang Xu ◽  
Xiaohui Zeng
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Cycle Time ◽  
Elasticity Modulus ◽  
Uniaxial Compression Test ◽  
Test Machine ◽  
Full Curve ◽  
Compression Properties ◽  
Cement Asphalt Mortar ◽  
Ca Mortar

Uniaxial compression test of cement asphalt (CA) mortar specimens, due to drying and wetting cycle of 0, 2, 4 and 8 times, is carried out by using the electronic universal test machine, with the strain rate ranging from 1 × 10−5 s−1to 1 × 10−2 s−1. The effects of strain rate and drying and wetting cycle time on the compressive strength, elasticity modulus, and stress-strain full curve are investigated. Experimental results show that the strain-stress full curve of CA mortar is affected obviously by strain rate and drying and wetting cycle time. The compressive strength and elasticity modulus increase with the strain rate under the same drying and wetting cycle time. The compressive strength and elasticity modulus decrease with the increase of drying and wetting cycle time in the same strain rate. The lower the strain rate is, the greater the compressive strength and elasticity modulus of CA mortar decrease. When the strain rate is 1 × 10−5 s−1and drying and wetting cycle time is 8, the largest reduction of average compressive strength of CA mortar is 40.48%, and the largest reduction of elasticity modulus of CA mortar is 35.51%, and the influence of drying and wetting cycle on the compressive strength of CA mortar is greater than its influence on the elasticity modulus.

Uniaxial Compressive Strengths of Artificial Freshwater Ice

2011 ◽  
Vol 243-249 ◽  
pp. 4634-4637 ◽  
Author(s):  
Li Min Zhang ◽  
Zhi Jun Li ◽  
Qing Jia ◽  
Guang Wei Li ◽  
Wen Feng Huang
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Uniaxial Compression Test ◽  
Strain Rates ◽  
Precise Control ◽  
Freshwater Ice ◽  
Ice Surface ◽  
Loading Direction ◽  
Maximum Value ◽  
Lower Strain

The uniaxial compression test was performed on artificial freshwater ice with a precise control-temperature unit compression tester of ice under -5, -10, -15, -20 and-30°C temperatures and strain rates ranging from 10-8 to 10-2 s-1. The loading direction was parallel to ice surface. The results showed that the compressive strength was very sensitive to the strain-rate. The uniaxial compressive strengths reached the maximum value at the ductile-brittle transition region, and the region was gradually close to the lower strain-rate with the decreasing temperature of test. Both the strain-rate and uniaxial compressive strength dependences could be expressed in terms of power function in the relevant ductile range of strain-rate. The tests also revealed that failure stress of ice increases with decreasing of temperature at the same strain rate.

Effect of Emulsified Asphalt Content on Mechanical Property of Cement and Emulsified Asphalt Mortar

2014 ◽  
Vol 587-589 ◽  
pp. 1132-1136
Author(s):  
Yue Li ◽  
Ping Wang
Keyword(s):  
Compressive Strength ◽  
Bending Strength ◽  
Bending Test ◽  
Test Machine ◽  
Peak Strain ◽  
Test Results ◽  
Slurry System ◽  
Similar Appearance ◽  
Emulsified Asphalt ◽  
Ca Mortar

Uniaxial compression and bending test of CA mortar, which have six different dosage of emulsified asphalt and the same dry material, is carried out with a electronic universal test machine. It turns out that: when the dosage of emulsified asphalt is lacked, the CA mortar cannot be uniform and stable slurry system; within the range of 300~680 mL emulsified asphalt, slurry state of mortar is good, no separation, and have good liquidity, in this range, with the increasing dosage of emulsified asphalt, compressive strength, elastic modulus and peak strain are gradually reduced, while ratio of bending strength to compressive strength rise at the beginning, then decline within a narrow range; The 1st and 2nd slurry is not stable, they appear separation and the surfaced asphalt, which have similar appearance and mechanical properties to cement mortar, and the last four groups of test results have great difference from the former two groups.

A Study on Mechanical Performance and Mechanism of Cement Asphalt Mortar

2011 ◽  
Vol 197-198 ◽  
pp. 1023-1027
Author(s):  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Yang Jian Ou
Keyword(s):  
Compressive Strength ◽  
Mechanical Performance ◽  
Cement Ratio ◽  
Cement Asphalt Mortar ◽  
Ca Mortar ◽  
Asphalt Mortar ◽  
Performance And Mechanism ◽  
Solidified Body

This paper studies the effects of proportion of emulsion asphalt and cement, sand gradation and sand-to-cement ratio on 28d strength of CA mortar solidified body according to compressive strength. Results show that compressive strength of CA mortar evidently decreases with increase of quality ratio of emulsion asphalt and cement, and increases with sand gradation attenuated. 28d compressive strength of CA mortar obviously reduces when the sand-cement ratio is above 1.4. Mechanical performance and intensity capability of CA motor solidified body are determined by microstructure of solidified body and content of free asphalt, encapsulation and cementation state of microstructure.

Study of Dynamic Mechanical Properties on Cement Asphalt Mortar of High Elastic Type

2014 ◽  
Vol 1049-1050 ◽  
pp. 346-353
Author(s):  
Lei Fang ◽  
De Hua Deng ◽  
Jian Wei Peng ◽  
Yong Wang ◽  
Qing Tian
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strain Rate ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Mechanical Properties ◽  
Experimental Result ◽  
Dynamic Mechanical ◽  
Ca Mortar ◽  
Asphalt Mortar

Dynamic mechanical properties of high elastic type cement and asphalt mortar (CA mortar) for high-speed railway was studied by split Hopkinson pressure bar (SHPB) in this paper. The experimental result show that the compressive strength of CA mortar increases gradually with the increasing of strain-rate. However, the increasing rate of compressive of CA mortar decreases with the further increasing strain-rate. The increasing rate of compressive strength is 57.65% for the strain-rate ranging from 25.16 s-1to 35.79 s-1 and 20.39% for the strain-rate from 94.64 up to 111.15 s-1, respectively. The larger the strain-rate is, the more serious the cracking is when CA mortar specimen damaged. The specific energy adsorption of CA mortar increases with the increasing strain-rate.

Improved Roller Hemming System for High Volume Part Production

2011 ◽  
Vol 473 ◽  
pp. 168-175 ◽  
Author(s):  
Martin Zubeil ◽  
Karl Roll ◽  
Marion Merklein
Keyword(s):  
Strain Rate ◽  
Surface Quality ◽  
Automotive Industry ◽  
Dimensional Stability ◽  
Cycle Time ◽  
High Volume ◽  
Non Linear ◽  
Part Production

Roller hemming is usually applied for hang-on-parts such as hoods, doors or trunk-lids which all have complex non-linear geometries. The flange is often hemmed along both surfaces and edges which have 3D curvilinear shapes. Minimization of hemming defects and the requirement to improve cycle time of the roller hemming process are essential for roller hemmed hang-on-parts in the automotive industry. Different systems such as the driven roller hemming provide the possibility to increase the strain rate without loosing surface quality and dimensional stability. Investigating the influence of friction during roller hemming, results will give an understanding of the advantage for mentioned roller hemming systems.

scholarly journals Compressive Strength of Modified FRP Hybrid Bars

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1898
Author(s):  
Marek Urbański
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Basalt Fiber ◽  
Test Method ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Free Length ◽  
Compression Properties ◽  
Reinforced Polymer ◽  
Frp Bars

A new type of HFRP hybrid bars (hybrid fiber reinforced polymer) was introduced to increase the rigidity of FRP reinforcement, which was a basic drawback of the FRP bars used so far. Compared to the BFRP (basalt fiber reinforced polymer) bars, modification has been introduced in HFRP bars consisting of swapping basalt fibers with carbon fibers. One of the most important mechanical properties of FRP bars is compressive strength, which determines the scope of reinforcement in compressed reinforced concrete elements (e.g., column). The compression properties of FRP bars are currently ignored in the standards (ACI, CSA). The article presents compression properties for HFRP bars based on the developed compression test method. Thirty HFRP bars were tested for comparison with previously tested BFRP bars. All bars had a nominal diameter of 8 mm and their nonanchored (free) length varied from 50 to 220 mm. Test results showed that the ultimate compressive strength of nonbuckled HFRP bars as a result of axial compression is about 46% of the ultimate strength. In addition, the modulus of elasticity under compression does not change significantly compared to the modulus of elasticity under tension. A linear correlation of buckling load strength was proposed depending on the free length of HFRP bars.

scholarly journals Static Mechanical Properties of Expanded Polypropylene Crushable Foam

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Przemysław Rumianek ◽  
Tomasz Dobosz ◽  
Radosław Nowak ◽  
Piotr Dziewit ◽  
Andrzej Aromiński
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strain Rate ◽  
Energy Absorption ◽  
Experimental Tests ◽  
Absorption Capacity ◽  
Strain Rates ◽  
Foam Density ◽  
Energy Absorption Capacity ◽  
Closed Cell

Closed-cell expanded polypropylene (EPP) foam is commonly used in car bumpers for the purpose of absorbing energy impacts. Characterization of the foam’s mechanical properties at varying strain rates is essential for selecting the proper material used as a protective structure in dynamic loading application. The aim of the study was to investigate the influence of loading strain rate, material density, and microstructure on compressive strength and energy absorption capacity for closed-cell polymeric foams. We performed quasi-static compressive strength tests with strain rates in the range of 0.2 to 25 mm/s, using a hydraulically controlled material testing system (MTS) for different foam densities in the range 20 g/dm3 to 220 g/dm3. The above tests were carried out as numerical simulation using ABAQUS software. The verification of the properties was carried out on the basis of experimental tests and simulations performed using the finite element method. The method of modelling the structure of the tested sample has an impact on the stress values. Experimental tests were performed for various loads and at various initial temperatures of the tested sample. We found that increasing both the strain rate of loading and foam density raised the compressive strength and energy absorption capacity. Increasing the ambient and tested sample temperature caused a decrease in compressive strength and energy absorption capacity. For the same foam density, differences in foam microstructures were causing differences in strength and energy absorption capacity when testing at the same loading strain rate. To sum up, tuning the microstructure of foams could be used to acquire desired global materials properties. Precise material description extends the possibility of using EPP foams in various applications.

Effect of strain rate, off-axis loading and high-velocity impact damage on the compressive strength of C/SiC composite

2018 ◽  
Vol 53 (4) ◽  
pp. 535-546 ◽  
Author(s):  
M Altaf ◽  
S Singh ◽  
VV Bhanu Prasad ◽  
Manish Patel
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
High Velocity ◽  
Impact Damage ◽  
The Other ◽  
High Velocity Impact ◽  
Fibre Bundles ◽  
Velocity Impact ◽  
Kink Bands ◽  
Other Hand

The compressive strength of C/SiC composite at different strain rates, off-axis orientations and after high-velocity impact was studied. The compressive strength was found to be 137 ± 23, 130 ± 46 and 162 ± 33 MPa at a strain rate of 3.3 × 10−5, 3.3 × 10−3, 3.3 × 10−3 s−1, respectively. On the other hand, the compressive strength was found to be 130 ± 46, 99 ± 23 and 87 ± 9 MPa for 0°/90°, 30°/60° and 45°/45° fibre orientations to loading direction, respectively. After high-velocity impact, the residual compressive strength of C/SiC composite was found to be 58 ± 26, 44 ± 18 and 36 ± 3.5 MPa after impact with 100, 150 and 190 m/s, respectively. The formation of kink bands in fibre bundles was found to be dominant micro-mechanism for compressive failure of C/SiC composite for 0°/90° orientation. On the other hand, delamination and the fibre bundles rotation were found to be the dominant mechanism for off-axis failure of composite.

Hot Compression Deformation Behavior of Spray-Formed AlSn20Cu Alloy

2021 ◽  
Vol 1035 ◽  
pp. 189-197
Author(s):  
Bao Ying Li ◽  
Bao Hong Zhu
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Phase Distribution ◽  
True Stress ◽  
Hot Compression ◽  
Test Machine ◽  
Hot Compression Deformation ◽  
Compression Deformation

The hot deformation behavior of spray-formed AlSn20Cu alloy during hot compression deformation was studied, and the constitutive equation of AlSn20Cu alloy was established. The samples of spray-formed AlSn20Cu alloy were compressed on Gleeble-3500 thermal simulation test machine. The error of the true stress caused by adiabatic heating effect in the experiment was corrected. The constitutive equation of spray-formed AlSn20Cu alloy could be represented by Zener-Hollomon parameter in a hyperbolic sine function. The results showed that the deformation temperatures and strain rates had a notable effect on the true stress of the alloy. At the identical deformation temperature, the true stress increased with the increase of strain rate. When the strain rate was constant, the stress decreased with the increase of deformation temperature. After hot compression deformation, the tin phase was elongated along the direction perpendicular to the compression axis with short strips and blocks. With the increase of deformation temperature and the decrease of strain rate, Sn phase distribution became more homogeneous.

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