Direct measurement of axial compressive strength of carbon fibers using multifilament method

2022 ◽  
Author(s):  
Wang Zhixin ◽  
Gao Aijun ◽  
Xu Lianghua ◽  
Tong Yuanjian
Keyword(s):  
Compressive Strength ◽  
Direct Measurement ◽  
Carbon Fibers ◽  
Axial Compressive Strength

Axial compressive strength of CHS T-joints reinforced with external stiffening rings

2017 ◽  
pp. 285-293
Author(s):  
L. Zhu ◽  
Y. Wei ◽  
K. Yang ◽  
Y. Bai ◽  
H.L. Sun
Keyword(s):  
Compressive Strength ◽  
T Joints ◽  
Axial Compressive Strength

scholarly journals Physical and Mechanical Properties of Cemented Ash-Based Lightweight Building Materials with and without Pumice

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Neslihan Doğan-Sağlamtimur ◽  
Adnan Güven ◽  
Ahmet Bilgil
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Building Material ◽  
Building Materials ◽  
Physical And Mechanical Properties ◽  
Mixing Ratio ◽  
Lightweight Material ◽  
Important Input ◽  
Axial Compressive Strength ◽  
International Companies

Pumice, cements (CEM I- and CEM II-type), waste fly and bottom ashes (IFA, GBA, and BBA) supplied from international companies were used to produce lightweight building materials, and physical-mechanical properties of these materials were determined. Axial compressive strength (ACS) values were found above the standards of 4 and 8 MPa (Bims Concrete (BC) 40 and 80 kgf/cm2 class) for cemented (CEM I) pumice-based samples. On the contrary, the ACS values of the pumice-based cemented (CEM II) samples could not be reached to these standards. Best ACS results (compatible with BC80) from these cemented lightweight material samples produced with the ashes were found in 50% mixing ratio as 10.6, 13.2, and 20.5 MPa for BBA + CEM I, GBA + CEM II, and IFA + CEM I, respectively, and produced with pumice were found as 8.4 MPa (same value) for GBA + pumice + CEM II (in 25% mixing ratio), BBA + pumice + CEM I (in 100% mixing ratio), and pumice + IFA + CEM I (in 100% mixing ratio), respectively. According to the results, cemented ash-based lightweight building material produced with and without pumice could widely be used for constructive purposes. As a result of this study, an important input to the ecosystem has been provided using waste ashes, whose storage constitutes a problem.

Fuzzy application in the prediction of axial compressive strength of Portland concrete based on traces and curing time

2021 ◽  
Author(s):  
DENNIS SANTOS TAVARES ◽  
BRUNA CAMPOS AMARAL ◽  
DAVID AUGUSTO RIBEIRO ◽  
TADAYUKI YANAGI JUNIOR ◽  
FRANCISCO CARLOS GOMES ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Construction Industry ◽  
Fuzzy Systems ◽  
Main Property ◽  
Membership Functions ◽  
Curing Time ◽  
Axial Compressive Strength ◽  
Compressive Strength Of Concrete ◽  
Input Variables ◽  
Main Material

Concrete is the main material used in the construction industry and its main property is the axial compressive strength. Usually the prediction of compressive strength is restricted to limited empirical equations and / or laboratory dosages. The objective of this study is to develop fuzzy systems capable of obtaining the axial compressive strength of concrete, from the mixtures and curing time. Several fuzzy systems were developed with Mamdani inference and different defuzzification methods. Triangular membership functions were adopted for the input variables in all systems and triangular functions for the output variables. The developed models were simulated and evaluated using three statistical indexes. The systems with Mamdani inference and centroid, bisector and mom defuzzification proved to be reliable and highly effective. The best performance was obtained by the fuzzy centroid defuzzification system according to the analyses.,

scholarly journals Influence of Humidity on the Elastic Modulus and Axis Compressive Strength of Concrete in a Water Environment

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5696
Author(s):  
Guohui Zhang ◽  
Changbing Li ◽  
Hai Wei ◽  
Mingming Wang ◽  
Zhendong Yang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Water Saturation ◽  
Water Environment ◽  
Systematic Research ◽  
Saturation State ◽  
Soaking Time ◽  
Axial Compressive Strength ◽  
Saturated Concrete ◽  
Compressive Strength Of Concrete

Concrete structures are often in different humidity conditions that have a significant impact on the elastic modulus of concrete, therefore, systematic research on the evolution of the law of concrete elastic modulus under different humidity conditions is needed. In this study, the variation laws of the water saturation of concrete specimens with strength grades C15, C20, and C30 were obtained, and then the influence laws of the water saturation on the concrete axial compressive strength were carried out, and the prediction model of elastic modulus of concrete with respect to water saturation was constructed. The results showed that the water saturation of concrete with strength grades C15, C20, and C30 increased with an extension of immersion time, and the water saturation showed an approximately linear rapid growth within three soaking hours, reaching 47.56%, 71.63%, and 47.29%, respectively. Note, the concrete reached saturation state when the soaking time was 240 h. The axial compressive strength with strength grades C15, C20, and C30 decreased with increased water saturation, and the axial compressive strength of saturated concrete decreased by 27.25%, 21.14%, and 20.76%, respectively, as compared with the dry state concrete. The elastic modulus of concrete with strength grades C15, C20, and C30 increased with increased water saturation, and the elastic modulus of saturated concrete was 1.18, 1.19, and 1.24 times higher than those of dry concrete, respectively.

Carbon fiber reinforced tin-superconductor composites

1989 ◽  
Vol 4 (6) ◽  
pp. 1339-1346 ◽  
Author(s):  
C. T. Ho ◽  
D. D. L. Chung
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Tensile Modulus ◽  
Tensile Load ◽  
Tensile Fracture ◽  
Fiber Direction ◽  
Continuous Carbon Fiber

Unidirectional and continuous carbon fiber tin-matrix composites were used for the packaging of the high-temperature superconductor YBa2Cu3O7–δ by diffusion bonding at 170 °C and 500 psi. Tin served as the adhesive and to increase the ductility, the normal-state electrical conductivity, and the thermal conductivity. Carbon fibers served to increase the strength and the modulus, both in tension along the fiber direction and in compression perpendicular to the fiber layers, though they decreased the strength in compression along the fiber direction. Carbon fibers also served to increase the thermal conductivity and the thermal fatigue resistance. At 24 vol. % fibers, the tensile strength was approximately equal to the compressive strength perpendicular to the fiber layers. With further increase of the fiber content, the tensile strength exceeded the compressive strength perpendicular to the fiber layers, reaching 134 MPa at 31 vol. % fibers. For fiber contents less than 30 vol. %, the compressive ductility perpendicular to the fiber layers exceeded that of the plain superconductor. At 30 vol. % fibers, the tensile modulus reached 15 GPa at room temperature and 27 GPa at 77 K. The tensile load was essentially sustained by the carbon fibers and the superconducting behavior was maintained after tension almost to the point of tensile fracture. Neither Tc nor Jc was affected by the composite processing.

scholarly journals Behavior of unconfined and CFRP confined rubberized concrete

2019 ◽  
Vol 15 (1) ◽  
pp. 65-83
Author(s):  
Rana Faisal Tufail ◽  
Xiong Feng ◽  
Muhammad Zahid
Keyword(s):  
Compressive Strength ◽  
Axial Strain ◽  
High Strength ◽  
Deformation Capacity ◽  
Rubberized Concrete ◽  
Conventional Concrete ◽  
Externally Bonded ◽  
Axial Compressive Strength ◽  
Strength And Deformation ◽  
Strength Models

Abstract The use of rubberized concrete (RuC) is an effective environmental approach to reduce the amount of scrap tires around the world. However, there are serious concerns regarding the compressive strength of RuC. This article investigates the use of externally bonded carbon fiber reinforced polymer (CFRP) jackets on RuC to develop a novel high strength and deformable CFRP confined RuC. In this study, 66 RuC cylinders were cast with 0, 10, 20, 30, 40 and 50% fine or coarse rubber to replace mineral aggregates. The RuC cylinders were then confined with one, two or three layers of CFRP jackets. The results indicated 208% high lateral strains in unconfined RuC as compared to the conventional concrete. CFRP jacketing was highly effective for enhancing the compressive strength and deformation capacity of RuC, where high compressive strength enhancement of 52 MPa and deformation capacity (317% axial strain) was achieved. The confined compressive strength test results were compared with the strength models to assess their validity for CFRP confined RuC. An analysis-oriented strength model was developed to predict the axial compressive strength of RuC confined by CFRP jackets. Overall, this study demonstrated the potential of using CFRP-confined RuC as a new structural material with improved strength and deformation.

Evaluation of Relations among Basic Mechanical Properties of Concrete with Machine-Made Sand

2011 ◽  
Vol 418-420 ◽  
pp. 441-444 ◽  
Author(s):  
Feng Lan Li ◽  
Yan Zeng ◽  
Chang Yong Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Rough Surface ◽  
Design Code ◽  
Ordinary Concrete ◽  
Axial Compressive Strength ◽  
Different Characteristics

Due to many different characteristics such as irregular polygon particle with pointed edges, rough surface and larger content of stone powder, machine-made sand has ignorable effects on the properties of concrete. As the basis for the design of concrete structures, the relations among the basic mechanical properties of concrete such as compressive strength, tensile strength, flexural strength and elastic modulus should be clearly understood. This paper summarizes the test data from the published references, and discusses the relations among these properties by statistical analyses compared with those of ordinary concrete. The results show that the axial compressive strength and the tensile strength can be prospected by the same formulas of ordinary concrete specified in current Chinese design code, but the prospected tensile strength should multiply a reducing coefficient when the strength grade of concrete is lower than C30. The elastic modulus of concrete with machine-made sand is larger than that of ordinary concrete, which should be prospect by the formula in this paper. Meanwhile, the formula of flexural strength is suggested.

scholarly journals Experimental Research on High Temperature Resistance of Modified Lightweight Concrete after Exposure to Elevated Temperatures

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ke-cheng He ◽  
Rong-xin Guo ◽  
Qian-min Ma ◽  
Feng Yan ◽  
Zhi-wei Lin ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Modification Method ◽  
Superior Mechanical Properties ◽  
Axial Compressive Strength ◽  
Crushed Limestone

In order to improve the spalling resistance of lightweight aggregate concrete at high temperature, two types of modified materials were used to modify clay ceramsite lightweight aggregates by adopting the surface coating modification method. Spalling of the concrete specimens manufactured by using the modified aggregates was observed during a temperature elevation. Mass loss and residual axial compressive strength of the modified concrete specimens after exposure to elevated temperatures were also tested. Concrete specimens consisting of ordinary clay ceramsites and crushed limestone were manufactured as references for comparison. The results showed that the ordinary lightweight concrete specimens and the crushed limestone concrete specimens were completely spalled after exposure to target temperatures above 400°C and 1000°C, respectively, whereas the modified concrete specimens remained intact at 1200°C, at which approximately 25% to 38% of the residual compressive strength was retained. The results indicated that the modified lightweight concrete specimens have exhibited superior mechanical properties and resistance to thermal spalling after exposure to elevated temperatures.

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