scholarly journals Calculation of the normal section strength of rubcon beams using deformation diagrams

2019 ◽  
Vol 135 ◽  
pp. 03067
Author(s):  
Aleksei Polikutin ◽  
Yuri Potapov ◽  
Artem Levchenko
Keyword(s):  
Cross Sections ◽  
High Strength ◽  
Strength Properties ◽  
Polymer Concrete ◽  
Test Results ◽  
Pure Bending ◽  
Normal Section ◽  
Rubber Concrete ◽  
Disperse Reinforcement ◽  
Deformation Diagrams

Rubber concrete (rubcon) - polymer concrete, which has high strength properties, as well as the constructions made of it. Fibrorubcon – rubber concrete with the addition of disperse reinforcement. On the basis of test results for pure bending, empirical dependencies and prerequisites for adapting existing methods for calculating the strength of normal sections of rubcon and fibrorubcon beams were obtained. These studies allow developing methods for calculating the normal cross sections of bending elements made of rubber concrete using deformation diagrams and taking into account the work of stretched polymer concrete.

scholarly journals Prerequisites for accounting of fiber reinforcement when calculating normal sections of fibrorubcon beams

2019 ◽  
Vol 7 (1) ◽  
pp. 66-69
Author(s):  
Алексей Поликутин ◽  
Aleksey Polikutin ◽  
Юрий Потапов ◽  
Yuriy Potapov ◽  
Артем Левченко ◽  
...  
Keyword(s):  
Fiber Reinforcement ◽  
High Strength ◽  
Polymer Concrete ◽  
Pure Bending ◽  
Limit States ◽  
A Value ◽  
Methods Of Calculation ◽  
Steel Cord ◽  
Multi Level ◽  
Rubber Concrete

Develop recommendations for the use of polymer-concrete bending structures is impossible without the creation or optimization of existing methods of calculation, this is especially true for bending elements that use multi-level reinforcement. Для применения (especially under the influence of aggressive environment) for use as a material for the manufacture of bending structures, we offer rubber concrete. – polymer-concrete, which is characterized by high strength characteristics. It is important to note that the composition of fibrorubcon used industrial waste such as fly ash and steel cord. Beams made from cauton and fibrocahuton were tested for pure bending - the most characteristic form of loading in the study of such elements. As a result of the theoretical studies of polymer concrete beams, the prerequisites were established for the calculation of the first group of limit states of rubcon beams and the method for calculating fibrorubcon beams was optimized. It was determined that fiber reinforcement with a percentage of reinforcement by mass of the rubcon element equal to 2.5% corresponds to the work of rod longitudinal reinforcement with a value of μ = 0.34%.

Study on the Compressive Strength and Mixing of Ultra-High Performance Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 825-828
Author(s):  
Su Li Feng ◽  
Peng Zhao
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Properties ◽  
Test Method ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Ultra High Performance Concrete ◽  
Mixture Ratio

The test in order to obtain liquidity, higher intensity ultra-high performance concrete(UHPC), in the course of preparation, high intensity quartz sand to replace the ordinary sand,reasonable mixture ratio control low water-cement ratio,the incorporation of part of the test piece ofsteel fibers, produced eight specimens . In the ordinary molding and the standard conservation 28d thecase, the ultra-high-performance concrete compressive strength of more than 170MPa.Thepreparation of the test method and test results will provide the basis for further study of the law of themechanical properties of ultra high strength properties of concrete.

Effective Elements of Building Structures from Pipe Concrete

2019 ◽  
Vol 945 ◽  
pp. 80-84
Author(s):  
O.E. Sysoev ◽  
A.Y. Dobryshkin ◽  
Ye.O. Sysoyev
Keyword(s):  
Cross Sections ◽  
High Strength Concrete ◽  
High Efficiency ◽  
High Strength ◽  
Strength Properties ◽  
Building Structures ◽  
Strength Concrete ◽  
Concrete Pipe ◽  
Bending Load ◽  
Concrete Elements

The article is devoted to the investigation of pipe-concrete prestressed structural elements with high efficiency. This is due to a more complete use of the strength properties of structural materials in the pipe-concrete beam. The article presents various methods for calculating pipe-concrete elements. The design of a concrete tube with a prestressed element using high-strength concrete is presented. The results of calculations of various designs are shown and the cross-sections of beams for perception of the same bending load are selected. A comparison is made between the consumption of beam materials of various designs. The effectiveness of the use of pipe-concrete elements for receiving bending loads made of high-strength concrete with prestressed reinforcement is shown in comparison with the construction of beams of traditional high-strength concrete, high-strength concrete pipe-concrete with no prestressing of reinforcement and metal beam, mass of the element, consumption of metal and concrete.

Use of Polymer for Rehabilitation of Uneven Settlement in Concrete Roadbed Slabs of Tunnels

2015 ◽  
Vol 1129 ◽  
pp. 468-473
Author(s):  
Jing Liu ◽  
Xin Guo Zheng ◽  
Shu Ming Li ◽  
Zhi Zeng ◽  
De Jun Yang ◽  
...  
Keyword(s):  
High Strength ◽  
Strength Properties ◽  
Test Results ◽  
Polymer Injection ◽  
Railway Tracks ◽  
Low Viscosity ◽  
Compressive Strength Test ◽  
Injection Technology

In some tunnels of railway lines located in water-rich region, due to the long-term water leakage and erosion, the foundation of railway lines showed large uneven settlement deformation, so the above concrete roadbed slabs also experienced uneven settlement accordingly. The smoothness of railway tracks diminished, and the speed of passing trains had to be limited to ensure safety. To restore the smoothness of the tracks, a dedicated polymer injection technology for quick uplift rehabilitation of uneven settlement concrete roadbed slabs was studied on site just within the specified daily skylight time (about 3 hours every day) of the railway lines. A hydrophobic polymer with low-viscosity, quick-setting and high-strength properties was used for injecting, filling and uplifting the concrete slabs in water-rich foundations. The high-precision electronic levels were adopted to monitor rising height of the tracks in real time. After rehabilitation, the filling quality of polymer injection under roadbed slabs was examined using Φ50 mm core samples and the strength of hardened polymer was verified by compressive strength test. Results indicated that the polymer could uplift the concrete roadbed slabs effectively and restore the smoothness of railway tracks accurately even in the water-rich environment. The research can provide some valuable references for quick rehabilitation of uneven settlement concrete roadbed slabs in water-rich tunnels.

Steel and Steel-Concrete Composite Columns of HEA-Cross-Sections with Member Imperfections, Subjected to Buckling Compression

2013 ◽  
Vol 743 ◽  
pp. 164-169
Author(s):  
Marcela Karmazínová
Keyword(s):  
Cross Sections ◽  
Initial Imperfection ◽  
High Strength ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Composite Columns ◽  
Geometrical Imperfection ◽  
Load Carrying ◽  
Buckling Resistance ◽  
Normal Strength

The paper deals with the problems of the load-carrying capacity of steel and steel-concrete composite members composed of high-strength materials, subjected to compression. The attention is mainly paid to the buckling resistance in the connection with member imperfections, which are usually covered by the equivalent initial geometrical imperfection expressed as the maximal initial member curving in the mid-length of the buckled member subjected to compression. The paper is oriented to the analytical solution of the initial eccentricity based on the conception of the buckling strength and to the possibilities how to verify the initial imperfection experimentally. The analysis of this problem is shown on the examples of steel and steel-concrete composite columns represented by open HEA cross-section and by the same cross-sections partially encased by normal-strength and high-strength concrete. Using test results of the specimens subjected to compression the comparison of actual values of initial imperfections with the corresponding theoretical values is presented here.

Mechanical properties and fatigue behavior of CO2 laser beam welded armor steel joints

2020 ◽  
Vol 62 (7) ◽  
pp. 689-697
Author(s):  
Z. Balalan ◽  
F. Sarsilmaz ◽  
O. Ekinci
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Heat Input ◽  
High Strength ◽  
High Heat ◽  
Strength Properties ◽  
Welding Parameters ◽  
Test Results ◽  
Input Parameters ◽  
High Heat Input

Abstract Armor 500T steel used in armored military vehicles and marine vehicles were joined by CO2 laser beam welding method by applying three welding powers and two welding speeds under shielding argon atmosphere. From microstructure and microhardness results, under low laser welding power and high welding traveling speeds, microstructural transformation in the joining region of the performed welds occurred at a narrower distance as compared to other parameters, and it was determined that four regions formed independent of each other for each parameter group. Furthermore, it was determined that there is a gradual decrease in the microharness values of samples in which welding parameters cause heat input to decrease. The fatigue test results of all samples showed high strength properties in the parameters with high heat input. Additionally, tensile test results for all samples with high heat input parameters also exhibited high strength properties. Fracture at the intersection at high heat input parameters of a relatively ductile separation type occurred in HAZ whereas, at other parameters fracture occurred at the weld center and wide gap semi-brittle fracture behavior was observed. As a consequence, it was found that the most effective parameter as compared with laser welding power is laser welding traveling speed.

Predicting Strain Reduction Factor for Concrete-Filled FRP Tube Columns Incorporating Interface Gap and Prestress

2017 ◽  
Vol 263 ◽  
pp. 18-23
Author(s):  
Thomas Vincent ◽  
Togay Ozbakkaloglu
Keyword(s):  
Cross Sections ◽  
High Strength ◽  
Reduction Factor ◽  
Test Results ◽  
Hoop Strain ◽  
Reinforced Polymer ◽  
Proposed Model ◽  
Frp Tube ◽  
Frp Tubes ◽  
Concrete Interface

This paper reports the findings from an analytical study into the influence of fiber reinforced polymer (FRP)-to-concrete interface gap and prestressed FRP tubes on strain reduction factor (kε) for concrete-filled FRP tube (CFFT) columns. A database that consists of a total of 45 aramid FRP- (AFRP) confined normal-and high-strength concrete (NSC and HSC) specimens with circular cross-sections is presented. All specimens were cylinders with a 152 mm diameter and 305 mm height, and their unconfined concrete strengths ranged from approximately 45 to 110 MPa. Analyses of the experimental databases that consisted of 22 specimens manufactured with FRP-to-concrete interface gap and a further 23 specimens prepared with lateral prestress is presented and discussed. Based on close examination of the hoop strain development on the FRP confining shell, expressions to predict strain reduction factors (kε) are proposed. The comparison of the proposed model predictions with the experimental test results of specimens prepared with an interface gap or prestressed FRP tubes shows good agreement.

Effect of Tempering Temperature on Strength and Fracture Toughness of 0.3C-CrMoV(ESR) Steel

2012 ◽  
Vol 710 ◽  
pp. 433-438 ◽  
Author(s):  
K. Saravanan ◽  
R. Suresh Kumar ◽  
V.M.J. Sharma ◽  
D. Sivakumar ◽  
P. Ramkumar ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
High Strength ◽  
Strength Properties ◽  
Strain Hardening Exponent ◽  
Fracture Toughness Test ◽  
Rolled Steel ◽  
Test Results ◽  
Space Applications ◽  
Tempering Temperature ◽  
Ring Segment

0.3C-CrMoV(ESR) steel is an ultra-high strength low alloy steel indigenously developed by ISRO for space applications. The steel is used in the form of rings of 2.8 m diameter also. In this paper, the effect of tempering temperature on ring rolled steel for the best combination of fracture toughness and strength properties is studied. The tensile properties and fracture toughness of the steel were evaluated in the as quenched and tempered conditions through the specimens drawn in radial direction of the ring segment. Five tempering temperatures were used in the study: 200, 450, 475, 500 and 510°C. Tensile strength of the steel showed continuous decrease with increasing tempering temperature, but yield strength increased reaching maximum when tempered at 450°C and further decreased with increasing tempering temperature. The elongation was higher for higher tempering temperature. The strain hardening exponent decreased with increasing tempering temperature. The fracture toughness test results showed that tempering between 475 and 510°C exhibited better combination of fracture toughness and strength.

A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 653-664
Author(s):  
IGNACIO DE SAN PIO ◽  
KLAS G. JOHANSSON ◽  
PAUL KROCHAK
Keyword(s):  
Negative Impact ◽  
High Strength ◽  
Strength Properties ◽  
Cellulose Microfibrils ◽  
Paper Strength ◽  
Flow Loop ◽  
Cationic Starch ◽  
Reflectance Measurement ◽  
Drainage Rate ◽  
Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

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