Design of Timber Single-Span Beam with Steel Reinforcement

2019 ◽  
Vol 972 ◽  
pp. 111-117
Author(s):  
Farid A. Boytemirov ◽  
Dmitry D. Koroteev ◽  
Makhmud Kharun
Keyword(s):  
Bearing Capacity ◽  
Research Work ◽  
Steel Reinforcement ◽  
Timber Beam ◽  
Joint Work ◽  
Inertia Moment ◽  
Limit Condition ◽  
Beam Design ◽  
Operation Process ◽  
Timber Beams

Vital problem, occurring in the operation process of structures such as timber beams, is the increase of their bearing capacity and span length with keeping their height. One of the possible ways to solve this problem is steel reinforcement of such structures. The aim of the research work is to show possibility of increasing bearing capacity of single-span reinforced timber beams and develop the main points of calculation and design of such structures. The beam is reinforced symmetrically by 2 rods d28 with both sides with Ar=24.63 cm2 (4d28 A300). The reinforcement is placed in compressed and stretched areas. Reinforced timber structures are designed on two groups of limit conditions. Design on the first limit condition (normal and tangential stress) is made using geometric characteristics of rectangular section of reinforced timber beam. Design on the second limit condition is made taking onto account the timber elastic nodule and inertia moment for reinforced timber beam. The main features of joint work of timber and reinforcement, which can increase operation reliability of bearing structures, are shown in the research work.

scholarly journals An Analysis of the Load-Bearing Capacity of Timber-Concrete Composite Beams with Profiled Sheeting

2017 ◽  
Vol 27 (4) ◽  
pp. 143-156 ◽  
Author(s):  
Maciej Szumigała ◽  
Ewa Szumigała ◽  
Łukasz Polus
Keyword(s):  
Numerical Analysis ◽  
Bearing Capacity ◽  
Concrete Slab ◽  
Composite Beams ◽  
Concrete Slabs ◽  
Timber Beam ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Shear Connectors ◽  
Timber Beams

Abstract This paper presents an analysis of timber-concrete composite beams. Said composite beams consist of rectangular timber beams and concrete slabs poured into the steel sheeting. The concrete slab is connected with the timber beam using special shear connectors. The authors of this article are trying to patent these connectors. The article contains results from a numerical analysis. It is demonstrated that the type of steel sheeting used as a lost formwork has an influence on the load-bearing capacity and stiffness of the timber-concrete composite beams.

scholarly journals Ballast treated with asphalt emulsion, Megarok and San Jose. AASTHO standards

2018 ◽  
Vol 2 (2) ◽  
pp. 79-87
Author(s):  
Maria Isabel Zambrano Meza ◽  
Edwin Alexander Rodriguez Veliz ◽  
Bethsy Anchundia Anchundia ◽  
Gema Cayetano Lucas ◽  
Gema Flores Ormaza
Keyword(s):  
Bearing Capacity ◽  
Research Work ◽  
Type A ◽  
San Jose ◽  
Asphalt Emulsion ◽  
Technical Specifications

In the research work, the results obtained at the laboratory level of the lending material (ballast) treated with asphalt emulsion from the quarries "Megarok and San José" are compared, applying the AASTHO standards. The quarries are located in the Picoazá-La Sequita parish of the Portoviejo canton. Samples from both quarries were evaluated in the laboratory and it was possible to carry out tests of natural humidity, Atterberg, granulometric, compaction, and soil bearing capacity (CBR). Based on the results obtained, they were compared by disclosing which of the quarries meets the appropriate conditions within the construction standards and techniques, in order to stabilize the material with asphalt emulsion; in addition to comparing it with the specifications of the AASTHO standards and the MTOP standard. The result was that the materials extracted from the quarries do not meet the technical specifications; but when mixed with the asphalt emulsion, the Megarok material fulfills as type A base.

scholarly journals Ultimate Compressive Strains and Reserves of Bearing Capacity of Short RC Columns with Basalt Fiber

2021 ◽  
Vol 11 (16) ◽  
pp. 7634
Author(s):  
Aleksandr V. Shilov ◽  
Alexey N. Beskopylny ◽  
Besarion Meskhi ◽  
Dmitry Mailyan ◽  
Dmitry Shilov ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
Short Fiber ◽  
Hydraulic Press ◽  
Steel Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Material Consumption ◽  
Short Columns

Increasing the bearing capacity of reinforced concrete structures, reducing material consumption, and ensuring quality are critical in modern construction. The article presents an experimental study of the ultimate compressive strains of short fiber basalt reinforced concrete columns and provides recommendations for increasing the bearing capacity using steel reinforcement bars with greater strength. The columns were tested in an upright position using a hydraulic press. Strains were measured with dial indicators and a strain gauge station. It was shown that the addition of 10% coarse basalt fiber increased the ultimate compressibility of concrete on ordinary crushed stone by 19.8%, and expanded clay concrete by 26.1%, which led to the strain hardening of concrete under compression by 9.0% and 12%, respectively. Ultimate compressive strains in fiber-reinforced concrete short columns with combined reinforcement increased 1.42 times in columns on a lightweight aggregate and 1.19 times on heavy aggregate. An increase in the ultimate compressibility of concrete makes it possible to use steel reinforcement with greater strength in compressed elements as the concrete crushing during compression occurs primarily due to the reaching of critical values by tensile stresses in the transverse direction. This makes it possible to manufacture structures with a higher load-bearing capacity and less material consumption. A practical example of the application of the proposed approach is given.

Experimental Study on Bending Behavior of Timber Beams Reinforced with CFRP/AFRP Hybrid FRP Sheets

2011 ◽  
Vol 255-260 ◽  
pp. 728-732
Author(s):  
Qing Chun ◽  
Jian Wu Pan
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Bearing Capacity ◽  
Strain Distribution ◽  
Failure Modes ◽  
Bending Behavior ◽  
Timber Beams

Based on the experiment of timber rectangle beams made of pine and fir reinforced with CFRP/AFRP hybrid FRP (HFRP) sheets. The failure modes and bending bearing capacity and load-deflection curves and strain distribution at mid-span section were analyzed. The results showed that: Comparing with the specimens without being reinforced by HFRP, there is certain improvement in bending bearing capacity and stiffness of the specimens reinforced with HFRP respectively. Bending bearing capacity of the pine specimens improve 18.1%~62.0% and bending bearing capacity of the fir specimens improve 7.7%~29.7%. Stiffness of the pine specimens improve 13%~21%, and stiffness of the fir specimens improve 6%~10%. Based on the experimental data, the computing formulas of bending bearing capacity of timber rectangle beams made of pine and fir reinforced with HFRP were presented.

scholarly journals Corrosion Prevention on Coated Rebars and Fiber in R.C Slabs

2018 ◽  
Vol 7 (3.34) ◽  
pp. 36
Author(s):  
Dr M.Tamil Selvi ◽  
Ms. J Hathari Evangalin ◽  
M.s S. Gayathri
Keyword(s):  
Research Work ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Accelerated Corrosion ◽  
Structural Problems ◽  
Nylon Fiber ◽  
Cell Measurement ◽  
Accelerated Corrosion Test ◽  
Rc Slabs ◽  
Corrosion Of Steel

Concrete structures prevail primarily due to prior attrition of steel due to preterm failure of rebars. The major cause of deterioration is the corrosion of the steel reinforcement, that can lead to structural problems. By utilizing our knowledge on corrosion of steel reinforcement, concrete structures could be made more durable. The research work is intend at arrestcorrosion in RC slabs by glazing silicon tombac to the steel rods. Nylon fiber is induced in concrete to attain strength for the concrete. A study report carried the effects of coating material between the conventional and fibers in concrete was compared with that of uncoated material between the conventional and fiber in concrete rebar’s. A continuous corrosion process is accelerated by inducing direct current to rebars. Process used to prompt corrosion is Accelerated corrosion test and Half-cell measurement.  

scholarly journals Effectiveness of Geogrids on Rutting and Bearing Capacity of Sub-base Course

2015 ◽  
Vol 15 (1) ◽  
pp. 77-80
Author(s):  
Ali Reza Mardookhpour
Keyword(s):  
Bearing Capacity ◽  
Soil Mechanics ◽  
Research Work ◽  
Polymer Materials ◽  
Load Carrying Capacity ◽  
Highway Projects ◽  
Load Carrying ◽  
Two Factors ◽  
Base Course ◽  
Increasing Load

Geogrids are being used in transportation application often in embankment construction due to their ease of construction and economy compared to traditional methods. Utilizing polymer materials in order to improve the performance of road structure is based on two factors, decreasing deformation and increasing bearing capacity. In this study geogrids were tested to check the ability of increasing load carrying capacity for highway projects. The purpose of this research work was to find a relation between the loading of the geogrid, the thickness of the aggregate layer and its bearing capacity. This would normally lead to an investigation on the lateral restrain behavior of a geogrid. According to the results obtained from soil mechanics laboratory, it could be demonstrated that by utilizing geogrids , the probability of occurring rutting decreases 30% and the bearing capacity of soil increase 40 % respectively.DOI: http://dx.doi.org/10.3126/njst.v15i1.12020  Nepal Journal of Science and TechnologyVol. 15, No.1 (2014) 77-80

scholarly journals Design and mechanical behavior study of ultrahigh-torque variable pitch casing joint

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881408
Author(s):  
Liangliang Dong ◽  
Jing Wang ◽  
Xiaohua Zhu
Keyword(s):  
Mechanical Behavior ◽  
Bearing Capacity ◽  
Oil And Gas ◽  
Research Work ◽  
Horizontal Section ◽  
Variable Pitch ◽  
Compression Load ◽  
Bending Load ◽  
Torque Load ◽  
Surface Angle

The top drive for casing running system can effectively avoid borehole neck down and sticking, reducing construction period by about 50%. However, the casing will bear higher torque load, and the casing joint threads can meet the bearing performance, which have a critical impact on casing running and the life of oil and gas wells. Variable pitch can reduce thread stress concentration and improve load-bearing strength. Lacking research on mechanical behavior has greatly restricted the development of variable pitch thread. This article generated a variable pitch casing joint thread helix forming method and control equation; designed an ultrahigh-torque variable pitch casing joint thread based on the theory of screw transformation matrix; established a three-dimensional finite element model of the variable pitch casing joint; optimized the main structure parameters with the judgment of torque-bearing capacity; and conducted parameter-sensitivity evaluation of guide surface angle, bearing surface angle, pitch of box thread, and amount of varying pitch under tension load, compression load, bending load, and torque load. The designed variable pitch casing joint had been successfully used in several top driving casing running wells, downed to the maximum depth of 4375 m, the largest hole deviation angle of 55.37° and horizontal section length of about 260 m. Under a torque of 4000 N m, the top drive rotated down into the gas well successfully without failure. The research work of this article has significance on variable pitch thread and enhances the bearing capacity of the thread.

Influences of Scarf-Joint of the Laminae in the Strength and Elasticity of Glued Laminated Timber Beams

2017 ◽  
Vol 864 ◽  
pp. 336-340 ◽  
Author(s):  
E.V.M. Carrasco ◽  
J.N.R. Mantilla ◽  
M.A. Smits ◽  
V.D. Pizzol ◽  
P.V. Krüger ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Linear Regression ◽  
Modulus Of Elasticity ◽  
Effective Elastic Modulus ◽  
Araucaria Angustifolia ◽  
Timber Beam ◽  
Glued Laminated Timber ◽  
Scarf Joint ◽  
Timber Beams

The objective of this work is to determinate the influence of the scarf-jointed in the strength and the modulus of elasticity of the glued laminated timber beam. To determine this influence, several tests with the outer laminae with scarf-joint and the bevel with different inclinations has been made. The models were made of Parana Pine, Araucaria angustifolia. For the tests were performed three points bending. With the load values and the deflection at mid-span and by linear regression were determined the effective elastic modulus. The results indicate that the performance is reduced considerably in the presence of a scarf-joint in the external laminae and also the reduction is greater when the scarf angle increases.

Consideration of Gustafsson's proposed Eurocode 5 failure criterion for notched timber beams

1993 ◽  
Vol 20 (6) ◽  
pp. 1030-1036 ◽  
Author(s):  
Ian Smith ◽  
Gerret Springer
Keyword(s):  
Fracture Energy ◽  
Key Words ◽  
Failure Criterion ◽  
Structural Design ◽  
Complete Solution ◽  
Design Criterion ◽  
Design Codes ◽  
Beam Design ◽  
Theoretical Predictions ◽  
Timber Beams

Experimental results and theoretical predictions for failure of timber beams with end notches, or cuts on the tension face, are discussed. The validity of Gustafsson's formula and the underlying assumptions are examined in the context of structural design codes. Attention is drawn to the arbitrary dependence of theoretical predictions on the load and geometric arrangement of specimens, and the method by which fracture energy is estimated. It is not intended at this stage to give a complete solution for the problem, but it is concluded to be premature to incorporate the proposed Eurocode 5 failure criterion for notched beams into the Canadian Standard CAN/CSA 086.1. Key words: timber, fracture, notched beam, design criterion.

scholarly journals EXPERIMENTAL INVESTIGATION OF LOAD-BEARING CAPACITY AND DEFLECTIONS OF FULL-SCALE GLUED LAMINATED TIMBER BEAMS

2020 ◽  
Vol 2 (61) ◽  
pp. 5-11
Author(s):  
S. Shekhorkina ◽  
◽  
К. Shliakhov ◽  
А. Sopilniak ◽  
◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Strength Class ◽  
Failure Load ◽  
Timber Structures ◽  
Load Bearing Capacity ◽  
Concentrated Load ◽  
Load Bearing ◽  
Glued Laminated Timber ◽  
Deformation Properties ◽  
Timber Beams

With the transition to the design of timber structures in accordance with European standards, problems arise in assessment of the load-bearing capacity of glued timber structures that are caused by insufficient amount of data about the physical, mechanical and deformation properties of glued timber, which is produced in Ukraine. The aim of the work was to determine the load bearing capacity in bending and deflection of a glued timber beam under the action of a concentrated load in the middle of the span. Two glued laminated timber beams were used in the experiment. Both beams were made using lumber from pine wood and a moisture-curing onecomponent polyurethane adhesive Kleiberit PUR 510 FiberBond. The beams have the dimensions of the cross-section: width of 120 mm and height of 180 mm. The length of the beams was 9880 mm. Each beam consisted of 9 layers of 20 mm thick lamellas glued together. Considering the absence of the data on the strength class of the beam material, the theoretical load bearing capacity and deflection were determined according to the characteristics of the GL24h class (minimum strength class), and amounted to 722 kgf and 19.1 cm, respectively. As a result of the tests, the failure load and the deflection of the beams were determined, and the dependences of the deflection on the load were obtained. The actual deflection of the beams determined was 251 mm and 275 mm, which is 1.31 and 1.44 times higher than the predicted deflection. Accordingly, the failure load determined experimentally is 1.96 and 2.03 times higher than the theoretical value. During the tests, the features of the deformation and the nature of the destruction of the beams were investigated. Wherein, the determining factor was the presence of defects in timber and lamellas joints along the length in the most stressed layers. Based on the data obtained, recommendations on manufacturing aimed at the increasing the bending strength of glued laminated timber beams are given. The results obtained will be further used in the development of structural solutions for hybrid timber-concrete floors.

Sign in / Sign up

Export Citation Format

Share Document