scholarly journals The tensile strength: The most fundamental mechanical characteristics of concrete

2021 ◽  
Vol 22 ◽  
pp. 1-4
Author(s):  
Andor Windisch

Concrete is an inhomogeneous building material. It has a considerable and reliable compressive strength and a relative low tensile strength which can be even exhausted locally under unfortunate conditions. It is quite obvious that the concrete tensile strength was always reprehended as the most unreliable concrete property. A simple relationship between tensile- and compressive strength is introduced. The mechanical background of the relation tensile- to compressive strength in case of ‘normal’ and high strength concretes is elucidated. Mechanical bond, too, relies completely on the tensile strength. In the design of structural concrete members the tension fields are more characteristic than the compression fields. Effective concrete strengths are not successful. Tensile strength can be applied as ‘yield condition’ for the lower bound solution in the theory of plasticity. The paper intends to contribute to the acceptance of the tensile strength as the more fundamental concrete characteristics.

Alloy Digest ◽  
2020 ◽  
Vol 69 (11) ◽  

Abstract Meehanite GB300 is a pearlitic gray cast iron that has a minimum tensile strength of 300 MPa (44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. This grade exhibits high strength while still maintaining good thermal conductivity and good machinability. It is generally used for applications where the thermal conductivity requirements preclude the use of other higher-strength materials, such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on physical properties, hardness, tensile properties, and compressive strength as well as fatigue. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: CI-75. Producer or source: Meehanite Metal Corporation.


2021 ◽  
Vol 1160 ◽  
pp. 25-43
Author(s):  
Naglaa Glal-Eldin Fahmy ◽  
Rasha El-Mashery ◽  
Rabiee Ali Sadeek ◽  
L.M. Abd El-Hafaz

High strength concrete (HSC) characterized by high compressive strength but lower ductility compared to normal strength concrete. This low ductility limits the benefit of using HSC in building safe structures. Nanomaterials have gained increased attention because of their improvement of mechanical properties of concrete. In this paper we present an experimental study of the flexural behavior of reinforced beams composed of high-strength concrete and nanomaterials. Eight simply supported rectangular beams were fabricated with identical geometries and reinforcements, and then tested under two third-point loads. The study investigated the concrete compressive strength (50 and 75 N/mm2) as a function of the type of nanomaterial (nanosilica, nanotitanium and nanosilica/nanotitanium hybrid) and the nanomaterial concentration (0%, 0.5% and 1.0%). The experimental results showed that nano particles can be very effective in improving compressive and tensile strength of HSC, nanotitanium is more effective than nanosilica in compressive strength. Also, binary usage of hybrid mixture (nanosilica + nanotitanium) had a remarkable improvement appearing in compressive and tensile strength than using the same percentage of single type of nanomaterials used separately. The reduction in flexural ductility due to the use of higher strength concrete can be compensated by adding nanomaterials. The percentage of concentration, concrete grade and the type of nanomaterials, could predominantly affect the flexural behavior of HSRC beams.


2010 ◽  
Vol 34-35 ◽  
pp. 1441-1444 ◽  
Author(s):  
Ju Zhang ◽  
Chang Wang Yan ◽  
Jin Qing Jia

This paper investigates the compressive strength and splitting tensile strength of ultra high strength concrete containing steel fiber. The steel fibers were added at the volume fractions of 0%, 0.5%, 0.75%, 1.0% and 1.5%. The compressive strength of the steel fiber reinforced ultra high strength concrete (SFRC) reached a maximum at 0.75% volume fraction, being a 15.5% improvement over the UHSC. The splitting tensile strength of the SFRC improved with increasing the volume fraction, achieving 91.9% improvements at 1.5% volume fraction. Strength models were established to predict the compressive and splitting tensile strengths of the SFRC. The models give predictions matching the measurements. Conclusions can be drawn that the marked brittleness with low tensile strength and strain capacities of ultra high strength concrete (UHSC) can be overcome by the addition of steel fibers.


2020 ◽  
Vol 7 (3) ◽  
pp. 115-139
Author(s):  
Sarkawt Karim ◽  
◽  
Azad Mohammed ◽  

This study describes two workability tests, compressive strength and tensile strength tests of high strength flowable concrete containing plastic fiber prepared from polyethylene terephthalate (PET) waste bottles. For the high fluidity mix Vebe time and V-funnel time tests were carried out. Results show that there is a Vebe time increase with PET fiber addition to concrete being increased with increasing fiber volume and fiber length. V-funnel time was found to reduce when up to 0.75% fiber volume is added to concrete, followed by an increase for larger fiber volumes. When fiber length is increase, there is more time increase, but in general, V-funnel time increase was lower than that of Vebe time, indicating a different influence of PET fiber on the compatibility and flowability. The measured V-funnel time for all mixes was found to conform to the limits of European specifications on the flowability of self compacting concrete. Small descending in compressive strength was recorded for RPET fiber reinforced concrete that reached 15.74 % for 1.5 percent fiber content with 10 mm fiber length. Attractive results was recorded in split tensile strength of RPET fibrous samples which resulted in improvement up to 63.3 % for 1.5 percent of 40 mm fiber length content.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Xiaosheng Liu ◽  
Weijun Wang ◽  
Quan Liu ◽  
Chao Yuan

The backfill of metal mines is easily damaged by the disturbance due to their low strength. We proposed a method that uses flexible meshes as the backfill skeleton to enhance the strength of the backfill. The physical and mechanical properties of the flexible mesh-reinforced filling body are investigated by combining theoretical analysis and laboratory experiments. The strengthening effect is remarkable with the flexible meshes. With the friction-passive resistance between the high-strength reinforcement material and the filling body, the insufficient tensile strength of the filling body is compensated and the reinforcement is improved. The ultimate compressive strength is increased by 1.07 to 1.35 times, and the elastic modulus is increased by 1.08 to 4.42 times. We concluded that the essence of strengthening the flexible mesh-reinforced filling is to increase the cohesive force of the filling and increase the ability to resist external load damage.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jawad Ahmad ◽  
Fahid Aslam ◽  
Rebeca Martinez-Garcia ◽  
Mohamed Hechmi El Ouni ◽  
Khalid Mohamed Khedher

AbstractSelf compacting concrete (SCC) is special type of concrete which is highly flowable and non-segregated and by its own mass, spreads into the formwork without any external vibrators, even in the presence of thick reinforcement. But SSC is also brittle nature like conventional concrete, which results in abrupt failure without giving any deformation (warning), which is undesirable for any structural member. Thus, self-compacting concrete (SCC) needs some of tensile reinforcement to enhance tensile strength and prevent the unsuitable abrupt failure. But fiber increased tensile strength of concrete more effectively than compressive strength. Hence, it is essential to add pozzolanic materials into fiber reinforced concrete to achieve high strength, durable and ductile concrete. This study is conducted to assess the performance of SCC with substitutions of marble waste (MW) and coconut fiber (CFs) into SCC. MW utilized as cementitious (pozzolanic) materials in percentage of 5.0 to 30% in increment of 5.0% by weight of binder and concrete is reinforced with CFs in proportion of 0.5 to 3.0% in increment of 0.5% by weight of binder. Rheological characteristics were measured through its filling and passing ability by using Slump flow, Slump T50, L-Box, and V-funnel tests while mechanical characteristics were measured through compressive strength, split tensile strength, flexure strength and bond strength (pull out) tests. Experimental investigation show that MW and CFs decrease the passing ability and filling ability of SCC. Additionally, Experimental investigation show that MW up to 20% and CFs addition 2.0% by weight of binder tend to increase the mechanical performance of SCC. Furthermore, statistical analysis (RSM) was used to optimize the combined dose of MW and CFs into SCC to obtain high strength self-compacting concrete.


2019 ◽  
Vol 8 (2) ◽  
pp. 5306-5310

Becoming modern waste have discovered the need to transfer of mechanical waste, The waste that must be arranged would two be able to be spared to use in some way, among the two modern waste preparing cementatious nature substances can be supplanted as folio include number in cement to separated. Ground Granulated Blast Furnaces Slag (GGBS) which used to be squander from an iron assembling industry, which used to be utilized as substitute of bond in cement because of its characteristic solidifying properties. To increase the strength of the concrete some of the special cements are used. Due to various codal specifications the binding material replacements of GGBS have been restricted up to 80% in maximum. In this project replacement of GGBS is done by an amount of 10% ,20% ,30% and 40%. In accordance with above restrictions the replacement variations in binding material have been decoded in a high strength concrete mixture. The research work have been extensively executed in almost all areas of testing like compressive strength , spilt tensile strength, and flexural strength, and also various primary tests like specific gravity , granular gradation etc. have also been excited to achieve high strength concrete.


Author(s):  
Faiq M. Al-Zwainy ◽  
Hussam k. Risan ◽  
Rana I. K. Zaki

The purpose of this study was to conduct a meta-analysis that shows the influence of fiber on ultimate compressive strength and tensile strength of ultra-high performance concrete. The internet scholarly search engines and ScienceDirect article references were used to illustrate the papers concerning the experimental investigations of mechanical properties of ultra-high strength concrete with and without fiber with clearly, completely and comparative raw data. The normal concrete test results were dismissed from this search. Seven trials were identified based on the adopted inclusion and exclusion criteria above. The meta-analysis based on standardized mean difference was carried out on the basis of a fixed-effects model for the major outcomes of the ultimate compressive and tensile properties of ultra-high performance concrete. A total of 888 test specimens were enrolled in these seven trials. The combined analysis yielded a sign of a significant improvement in ultimate compressive strength and tensile strength of ultra-high strength concrete with fiber addition of 2% by concrete volume. The summary effect size of ultimate compressive strength was 2.34 while a more improvement in term of tensile strength with effect size of 2.64. By addition fiber of 2% provides a significant benefit in mechanical properties of ultra-high performance concrete.


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