scholarly journals Experimental Investigation on the Mechanical Properties of Self-Compacting Concrete under Uniaxial and Triaxial Stress

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1830 ◽  
Author(s):  
Hongbo Li ◽  
Jianguang Yin ◽  
Pengfei Yan ◽  
Hao Sun ◽  
Qingqing Wan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Failure Mode ◽  
Substitution Rate ◽  
Peak Stress ◽  
Confining Pressure ◽  
Strength Test ◽  
Peak Strain ◽  
Self Compacting Concrete ◽  
Splitting Strength

To explore the influence of fly ash (FA) and silica fume (SF) on the mechanical properties of self-compacting concrete (SCC) under uniaxial and triaxial, the compressive strength test, splitting strength test, ultrasonic testing test, and triaxial test were performed in this paper. The results show that the 3 days compressive strength and splitting strength of SCC decreased with the increase of FA substitution rate. The 28 days, 56 days, and 91 days compressive strength and splitting strength of SCC increased first and then decreased with the increase of FA substitution rate. The peak stress and peak strain of SCC gradually increased with the increase of confining pressure. The peak stress and strain of SCC increased first and then decreased with the increase of FA substitution rate. Moreover, the relationship models between compressive strength and splitting strength, between compressive strength and amplitude, between peak stress, peak strain and confining pressure under different FA substitution rates were proposed. As a conclusion, the addition of SF can increase the strength of SCC obviously. Under uniaxial stress, SCC failure mode is splitting failure, under triaxial stress, SCC failure mode is shear failure. Based on the Mohr-Coulomb strength theory, the failure criterion of SCC with FA and SF was discussed.

Low Strength Self Compacting Concrete Compressive Strength Test

2013 ◽  
Vol 275-277 ◽  
pp. 2041-2044
Author(s):  
Feng Yan ◽  
Nan Pang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Compression Strength ◽  
Strength Test ◽  
The Self ◽  
Concrete Compressive Strength ◽  
Self Compacting Concrete ◽  
Intensity Index ◽  
Compressive Strength Test ◽  
Low Strength

In this paper,the mechanical properties were studied,the self compacting concrete cubic compression strength,prismatic compressive strength test,discussed two kinds of relationship between intensity index.

scholarly journals KARAKTERISTIK SELF COMPACTING CONCRETE (SCC) TANPA CURING

2018 ◽  
Author(s):  
erniati
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fresh Concrete ◽  
Strength Test ◽  
Splitting Tensile Strength ◽  
Good Resistance ◽  
Self Compacting Concrete ◽  
Compressive Strength Test ◽  
Resistance Durability

Self Compacting Concrete (SCC) is one solution to get concrete construction which it has good resistance. Durability of concrete was obtained by the good concrete compaction to be done by a skilled workforce. However, one of the negligence that often occur in the field ie after casting they was ignoring curing of the hardening concrete. This study discusses the workability of fresh concrete and mechanical properties (compressive strength and splitting tensile strength) on SCC without curing. Testing of the concrete workability based on EFNARC standard. The mechanical properties test based on ASTM standards. The method Compressive strength test based on ASTM standards 39 / C 39M - 12a, whereas splitting tensile strength accordance standard ASTM C496 / C496M-11. The results of the study indicate that the SCC without curing effect on the reduction in compressive strength at ages 1, 3, 7, 28, and 90 days in a row at 4.11 MPa (16.1%); 4.90 MPa (13.9%); 6.64 MPa (13.1%); and 6, 72 MPa (12.75%). Splitting tensile strength decreased respectively by 0.1 MPa (3.25%); 0.26 MPa (7.99%); 0.4 MPa (9.52%); and 0.39 MPa (9.16%).

scholarly journals SHPB Testing and Analysis of Bedded Shale under Active Confining Pressure

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Guoliang Yang ◽  
Jingjiu Bi ◽  
Xuguang Li ◽  
Jie Liu ◽  
Yanjie Feng
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Strain Rate ◽  
Peak Stress ◽  
Confining Pressure ◽  
Dynamic Mechanical Properties ◽  
Dynamic Elastic Modulus ◽  
Peak Strain ◽  
Dynamic Mechanical ◽  
Bedding Angle

Shale gas is the most important new energy source in the field of energy, and its exploitation is very important. The research on the dynamic mechanical properties of shale is the premise of exploitation. To study the dynamic mechanical properties of shale from the Changning-Weiyuan area of Sichuan Province, China, under confining pressure, we used a split Hopkinson pressure bar (SHPB) test system with an active containment device to carry out dynamic compression tests on shale with different bedding angles. (1) With active confining pressure, the shale experiences a high strain rate, and its stress-strain curve exhibits obvious plastic deformation. (2) For the same impact pressure, the peak stress of shale describes a U-shaped curve with an increasing bedding angle; besides, the peak stress of shale with different bedding angles increases linearly with rising confining pressure. The strain rate shows a significant confining pressure enhancement effect. With active confining pressure, the peak strain gradually decreases as the bedding angle increases. (3) As a result of the influence of different bedding angles, the dynamic elastic modulus of shale has obvious anisotropic characteristics. Shale with different bedding angles exhibits different rates of increase in the dynamic elastic modulus with rising confining pressure, which may be related to differences in the development of planes of weakness in the shale. The results of this study improve our understanding of the behavior of bedded shale under stress.

scholarly journals Influence of Granite Cutting Waste and Recycled Concrete on Properties of Self Compacting Concrete

2019 ◽  
Vol 8 (4) ◽  
pp. 205-208
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Strength Test ◽  
Recycled Concrete ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Slump Flow ◽  
Hardened Properties ◽  
Passing Ability

This paper explains the combined effect of granite cutting waste and recycled concrete on the workability and mechanical properties of self compacting concrete. Experimental plan is divided in such a way that granite cutting waste is replaced with fine aggregate at 0, 20,40,60,80 and 100% proportions. Recycled concrete is replaced with the coarse aggregate starting from 20 to 100%. Total 36 mixes were designed to check the fresh and hardened properties. Slump flow and T500, v-funnel and L-box test are conducted to know the flow ability and passing ability of concrete. To study the hardened properties compressive strength, flexural strength test values are to be collected.

scholarly journals Study on Mechanical Properties of Basalt Fiber Shotcrete in High Geothermal Environment

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7816
Author(s):  
Yueping Tong ◽  
Yan Wang ◽  
Shaohui Zhang ◽  
Yahao Chen ◽  
Zhaoguang Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Constitutive Model ◽  
Basalt Fiber ◽  
Strain Curve ◽  
Peak Stress ◽  
Curing Temperature ◽  
Peak Strain ◽  
Transverse Cracks ◽  
Geothermal Environments

With the development of infrastructure, there are growing numbers of high geothermal environments, which, therefore, form a serious threat to tunnel structures. However, research on the changes in mechanical properties of shotcrete under high temperatures and humid environments are insufficient. In this paper, the combination of various temperatures (20 °C/40 °C/60 °C) and 55% relative humidity is used to simulate the effect of environment on the strength and stress–strain curve of basalt fiber reinforced shotcrete. Moreover, a constitutive model of shotcrete considering the effect of fiber content and temperature is established. The results show that the early mechanical properties of BFRS are improved with the increase in curing temperature, while the compressive strength at a later age decreases slightly. The 1-day and 7-day compressive strength of shotcrete at 40 °C and 60 °C increased by 10.5%, 41.1% and 24.1%, 66.8%, respectively. The addition of basalt fiber can reduce the loss of later strength, especially for flexural strength, with a increase rate of 11.9% to 39.5%. In addition, the brittleness of shotcrete increases during high temperature curing, so more transverse cracks are observed in the failure mode, and the peak stress and peak strain decrease. The addition of basalt fiber can improve the ductility and plasticity of shotcrete and increase the peak strain of shotcrete. The constitutive model is in good agreement with the experimental results.

scholarly journals Mechanical Properties of Furnace Slag and Coal Gangue Mixtures Stabilized by Cement and Fly Ash

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7103
Author(s):  
Hongbo Li ◽  
Hubiao Zhang ◽  
Pengfei Yan ◽  
Changyu Yan ◽  
Yufei Tong
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Peak Stress ◽  
Coal Gangue ◽  
Replacement Rate ◽  
Splitting Strength ◽  
The Relationship

The mechanical properties and strength formation mechanism of cement–fly-ash-stabilized slag–coal gangue mixture were examined using an unconfined compressive strength test, splitting strength test, triaxial test, and scanning electron microscopy to solve the limitations of land occupation and environmental pollution that is caused by fly ash from the Xixia District thermal power plant in Yinchuan, slag from the Ningdong slag yard, and washed coal gangue. Its performance as a pavement base mixture on the road was investigated. The results demonstrated that as the slag replacement rate increased, the maximum water content increased while the maximum dry density decreased. The addition of slag reduced the unconfined compressive strength and splitting strength of the specimens; furthermore, the higher the slag substitution rate, the lower the unconfined compressive strength and splitting strength of the specimens. As the cement content increased, the specimen’s unconfined compressive strength increased. Based on the principle of considering the mechanical properties and economic concerns, the slag replacement rate in the actual construction should be ~50% and should not exceed 75%. Based on the relationship between the compressive strength and splitting strength of ordinary concrete, the relationship model between the unconfined compressive strength and splitting strength of cement–fly-ash-stabilized slag–coal gangue was established. The failure mode, stress–strain curve, peak stress, and failure criterion of these specimens were analyzed based on the triaxial test results, and the relationship formulas between the slag substitution rate, cement content, peak stress, and confining pressure were fitted. As per the SEM results, the mixture’s hydration products primarily included amorphous colloidal C-S-H, needle rod ettringite AFt, unhydrated cement clinker particles, and fly ash particles. The analysis of the mixture’s strength formation mechanism showed that the mixture’s strength was the comprehensive embodiment of all factors, such as the microaggregate effect, secondary hydration reaction, and material characteristics.

scholarly journals Mechanical Properties of Rock–Coal–Rock Composites at Different Inclined Coal Seam Thicknesses

2022 ◽  
Vol 9 ◽  
Author(s):  
Bo Ma ◽  
Feng Wang ◽  
Hongyang Liu ◽  
Dawei Yin ◽  
Zhiguo Xia
Keyword(s):  
Mechanical Properties ◽  
Coal Seam ◽  
Failure Modes ◽  
Peak Stress ◽  
Confining Pressure ◽  
Seam Thickness ◽  
Peak Strain ◽  
Confining Pressures ◽  
Coal Rock ◽  
Coal Seam Thickness

A comprehensive understanding of the mechanical properties of coal and rock sections is necessary for interpreting the deformation and failure modes of such underground sections and for evaluating the potential dynamic hazards. However, most studies have focused on horizontal coal–rock composites and the mechanical properties of inclined coal–rock composites have not been considered. To explore the influence of different confining pressures and inclined coal seam thicknesses on the mechanical properties and failure characteristics of rock–coal–rock (RCR) composites, a numerical model based on the particle flow code was used to perform simulations on five inclined RCR composites at different confining pressures. The results show that the mechanical properties and failure characteristics of the RCR composites are affected considerably by the inclined coal seam thickness and the confining pressure. (1) When the inclined coal seam thickness is constant, the elasticity modulus of the inclined RCR composite increases nonlinearly with the confining pressure at first, and then remains constant. At the same confining pressure, the elasticity modulus of the inclined RCR composite decreases nonlinearly with the inclined coal seam thickness. (2) When the confining pressure is constant, the peak stress of the inclined RCR composite decreases with the increase of the inclined coal seam thickness. When the inclined coal seam thickness is constant, the peak stress increases with the confining pressure. (3) As the inclined coal seam thickness increases, the peak strain of the inclined RCR composite first decreases rapidly, and then remains constant when there is no confining pressure. When the confining pressure is between 5 and 20 MPa, the peak strain of the inclined RCR composite gradually increases. (4) In the absence of confining pressure, there are few microcracks in the rock at an inclined coal seam thickness of 10 mm, whereas all the other cracks are in the coal section. When the confining pressure ranges between 5 and 20 MPa, the failure modes of the RCR composite can be divided into Y- and X-types.

scholarly journals KARAKTERISTIK SELF COMPACTING CONCRETE (SCC) TANPA CURING (CHARACTERISTIC OF SELF COMPACTING CONCRETE (SCC)WITHOUT CURING)

2018 ◽  
Author(s):  
Erniati Bachtiar
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fresh Concrete ◽  
Strength Test ◽  
Splitting Tensile Strength ◽  
Good Resistance ◽  
Self Compacting Concrete ◽  
Compressive Strength Test ◽  
Resistance Durability

Self Compacting Concrete (SCC) is one solution to get concrete construction which it has good resistance. Durability of concrete was obtained by the good concrete compaction to be done by a skilled workforce. However, one of the negligence that often occur in the field ie after casting they was ignoring curing of the hardening concrete. This study discusses the workability of fresh concrete and mechanical properties (compressive strength and splitting tensile strength) on SCC without curing. Testing of the concrete workability based on EFNARC standard. The mechanical properties test based on ASTM standards. The method Compressive strength test based on ASTM standards 39 / C 39M - 12a, whereas splitting tensile strength accordance standard ASTM C496 / C496M-11. The results of the study indicate that the SCC without curing effect on the reduction in compressive strength at ages 1, 3, 7, 28, and 90 days in a row at 4.11 MPa (16.1%); 4.90 MPa (13.9%); 6.64 MPa (13.1%); and 6, 72 MPa (12.75%). Splitting tensile strength decreased respectively by 0.1 MPa (3.25%); 0.26 MPa (7.99%); 0.4 MPa (9.52%); and 0.39 MPa (9.16%).

scholarly journals Mechanical Behavior of Brick Masonry in an Acidic Atmospheric Environment

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2694 ◽  
Author(s):  
Shansuo Zheng ◽  
Lihua Niu ◽  
Pei Pei ◽  
Jinqi Dong
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Acid Rain ◽  
Cement Mortar ◽  
Brick Masonry ◽  
Atmospheric Environment ◽  
Peak Strain ◽  
Lime Mortar ◽  
Attenuation Model

In order to evaluate the deterioration regularity for the mechanical properties of brick masonry due to acid rain corrosion, a series of mechanical property tests for mortars, bricks, shear prisms, and compressive prisms after acid rain corrosion were conducted. The apparent morphology and the compressive strength of the masonry materials (cement mortar, cement-lime mortar, cement-fly ash mortar, and brick), the shear behavior of the masonry, and the compression behavior of the masonry were analyzed. The resistance of acid rain corrosion for the cement-lime mortar prisms was the worst, and the incorporation of fly ash into the cement mortar did not improve the acid rain corrosion resistance. The effect of the acid rain corrosion damage on the mechanical properties for the brick was significant. With an increasing number of acid rain corrosion cycles, the compressive strength of the mortar prisms, and the shear and compressive strengths of the brick masonry first increased and then decreased. The peak stress first increased and then decreased whereas the peak strain gradually increased. The slope of the stress-strain curve for the compression prisms gradually decreased. Furthermore, a mathematical degradation model for the compressive strength of the masonry material (cement mortar, cement-lime mortar, cement-fly ash mortar, and brick), as well as the shear strength attenuation model and the compressive strength attenuation model of brick masonry after acid rain corrosion were proposed.

Comparison Analysis on the Mechanical Properties of HSC and NSC after the Action of High Temperatures

2014 ◽  
Vol 1014 ◽  
pp. 49-52
Author(s):  
Xiao Ping Su
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperatures ◽  
High Strength Concrete ◽  
Elasticity Modulus ◽  
Strain Curve ◽  
Peak Stress ◽  
High Strength ◽  
Peak Strain ◽  
Strength Concrete

With the wide application of high strength concrete in the building construction,the risk making concrete subject to high temperatures during a fire is increasing. Comparison tests on the mechanical properties of high strength concrete (HSC) and normal strength concrete (NSC) after the action of high temperature were made in this article, which were compared from the following aspects: the peak stress, the peak strain, elasticity modulus, and stress-strain curve after high temperature. Results show that the laws of the mechanical properties of HSC and NSC changing with the temperature are the same. With the increase of heating temperature, the peak stress and elasticity modulus decreases, while the peak strain grows rapidly. HSC shows greater brittleness and worse fire-resistant performance than NSC, and destroys suddenly. The research and evaluation on the fire-resistant performance of HSC should be strengthened during the structural design and construction on the HSC buildings.

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