scholarly journals Durability of concrete with CFRP wrapping

2018 ◽  
Vol 199 ◽  
pp. 09009
Author(s):  
Qian-Qian Yu ◽  
Xiang Li ◽  
Xiang-Lin Gu
Keyword(s):  
Bearing Capacity ◽  
Water Immersion ◽  
Weight Ratio ◽  
High Strength ◽  
Compression Tests ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Concrete Cylinders ◽  
Carbon Fibre Reinforced Polymer ◽  
Cfrp Wrapping

Carbon fibre-reinforced polymer (CFRP) material has a high strength-to-weight ratio and good resistance to corrosion and environmental attacks. It has been widely used in rehabilitation of aged infrastructure. However, the durability of the strengthened system has not been yet assessed thoroughly since most of the previous study was conducted based on accelerated tests while the long-term investigation was less reported. This paper investigated the effect of CFRP wrapping on the axial behaviour of concrete cylinders subjected to different environments for more than 13 years. The specimens were exposed to five different conditions, including standard curing, immersion in distilled water, immersion in saturated Na2SO4 solution, outdoor sheltered from the rain, and outdoor without shelter from the rain. Axial compression tests were performed on the wrapped concrete cylinders. The load-bearing capacity and stress-strain responses were recorded. It was found that CFRP wrapping could effectively improve the ultimate strength and ductility of the columns. Though scatter existed, no significant effect of the environmental exposure on the load-bearing capacity of the cylinder specimens was observed which indicates a good durability of the strengthening system.

scholarly journals The Efficiency of Utilisation of High-strength Steel in Tubular Profiles

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1193 ◽  
Author(s):  
Ieva Misiūnaitė ◽  
Viktor Gribniak ◽  
Arvydas Rimkus ◽  
Ronaldas Jakubovskis
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
High Strength Steel ◽  
Current Trend ◽  
Weight Ratio ◽  
High Strength ◽  
Beam Specimen ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Structural Applications

The use of high-strength steel (HSS) is a current trend of the construction industry. Tubular profiles are widely used in various structural applications because of their high stiffness-to-weight ratio, exceptional resistance to torsion, and aesthetic appearance. However, the increase of the strength for the same elastic modulus of the material and geometry of tubular profiles is often not proportional to the rise of the load-bearing capacity of the structural element. The obtained experimental results support the above inference. The study was based on the flexural test results of two groups of HSS and normal-strength steel (NSS) tubular specimens with a 100 × 100 × 4 mm (height × width × thickness) cross-section. Numerical (finite element) simulation results demonstrated that the shape of the cross-section influenced the efficiency of utilisation of HSS. The relationship between the relative increase of the load-bearing capacity of the beam specimen and the corresponding change of the steel strength determined the utilisation efficiency.

scholarly journals Experiences with Fibre Ropes as Hoist Ropes in Crane Applications

2020 ◽  
Vol 1 ◽  
pp. 9-18
Author(s):  
Ilaka Mupende ◽  
Felix Lukasch ◽  
Philipp Tonnier
Keyword(s):  
Bearing Capacity ◽  
Weight Ratio ◽  
High Strength ◽  
Load Bearing Capacity ◽  
Load Bearing

High strength polymer fibres are opening new fields in regard on their strength to weight ratio. In 2009 Liebherr and Teufelberger started a development partnership to utilise these opportunities and rethink the basics of hoist ropes for cranes: (1) Introduction; (2) The high strength fibre rope soLITE; (3) Load bearing capacity of the rope; (4) Liebherr fibre crane series; (5) Discard criteria.

Experimental Research on Behavior of CFRP Circular Steel Tubular Confined Recycled Aggregate Concrete Columns under Axial Compression

2015 ◽  
Vol 744-746 ◽  
pp. 96-99
Author(s):  
Jiong Feng Liang ◽  
Ze Ping Yang ◽  
Ming Hua Hu
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Concrete Columns ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Compression Tests ◽  
Load Bearing Capacity ◽  
Aggregate Concrete ◽  
Load Bearing ◽  
Cfrp Wrapping

In order to further promote the use of recycled aggregate concrete in practice, axial compression tests were carried out for 7 CFRP circular steel tubular confined recycled aggregate concrete columns. The influence of the replace rate of recycled aggregate concrete, the wrapping method on axial compression behavior of CFRP circular steel tubular confined recycled aggregate concrete columns were analyzed. Based on the results of the tests, with the replace rate of recycled aggregate concrete increasing, the specimens have an decreasing trend in the load bearing capacity. The whole CFRP wrapping circular steel tubular confined recycled aggregate concrete columns have higher load bearing capacity than the three stripe wrapping ones.

scholarly journals Bending Stiffness, Load-Bearing Capacity and Flexural Rigidity of Slender Hybrid Wood-Based Beams

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 703 ◽  
Author(s):  
Barbara Šubic ◽  
Gorazd Fajdiga ◽  
Jože Lopatič
Keyword(s):  
Bearing Capacity ◽  
Flexural Rigidity ◽  
Bending Stiffness ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Hybrid Beams ◽  
Fibre Reinforced Polymer

Modern architecture suggests the use of opened spaces with large transparent envelope surfaces. Therefore, windows of long widths and large heights are needed. In order to withstand the wind loads, such wooden windows can be reinforced with stiffer materials, such as aluminium (Al), glass-fibre reinforced polymer (GFRP), and carbon-fibre reinforced polymer (CFRP). The bending stiffness, load-bearing capacity, and flexural rigidity of hybrid beams, reinforced with aluminium, were compared through experimental analysis, using a four-point bending tests method, with those of reference wooden beams. The largest increases in bending stiffness (29%–39%), load-bearing capacity (33%–45%), and flexural rigidity (43%–50%) were observed in the case of the hybrid beams, with the highest percentage of reinforcements (12.9%—six reinforcements in their tensile and six reinforcements in their compressive zone). The results of the experiments confirmed the high potential of using hybrid beams to produce large wooden windows, for different wind zones, worldwide.

scholarly journals Soil compaction during harvest operations in five tropical soils with different textures under eucalyptus forests

2018 ◽  
Vol 42 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Paula Cristina Caruana Martins ◽  
Moacir de Souza Dias Junior ◽  
Ayodele Ebenezer Ajayi ◽  
Ernesto Norio Takahashi ◽  
Diego Tassinari
Keyword(s):  
Bearing Capacity ◽  
Soil Compaction ◽  
Sandy Loam ◽  
Traffic Intensity ◽  
Compression Tests ◽  
Load Bearing Capacity ◽  
Undisturbed Soil ◽  
Load Bearing ◽  
Structure Degradation ◽  
Precompression Stress

ABSTRACT Traffic of farm machinery during harvest and logging operations has been identified as the main source of soil structure degradation in forestry activity. Soil susceptibility to compaction and the amount of compaction caused by each forest harvest operation differs according to a number of factors (such as soil strength, soil texture, kind of equipment, traffic intensity, among many others), what requires the adequate assessment of soil compaction under different traffic conditions. The objectives of this study were to determine the susceptibility to compaction of five soil classes with different textures under eucalyptus forests based on their load bearing capacity models; and to determine, from these models and the precompression stresses obtained after harvest operations, the effect of traffic intensity with different equipment in the occurrence of soil compaction. Undisturbed soil samples were collected before and after harvest operations, being then subjected to uniaxial compression tests to determine their precompression stress. The coarse-textured soils were less resistant and endured greater soil compaction. In the clayey LVd2, traffic intensity below four Forwarder passes limited compaction to a third of the samples, whereas in the sandy loam PVd all samples from the 0-3 cm layer were compacted regardless of traffic intensity. The Feller Buncher and the Clambunk presented a high potential to cause soil compaction even with only one or two passes. The use of soil load bearing capacity models and precompression stress determined after harvest and logging operations allowed insight into the soil compaction process in forestry soils.

scholarly journals Fire Performance of Columns Made of Normal and High Strength Concrete: A Comparative Analysis

2016 ◽  
Vol 711 ◽  
pp. 564-571 ◽  
Author(s):  
Thomas Gernay
Keyword(s):  
Bearing Capacity ◽  
High Strength Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Strength Loss ◽  
Fire Performance ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Strength Concrete ◽  
The Impact

The use of high strength concrete (HSC) in multi-story buildings has become increasingly popular. Selection of HSC over normal strength concrete (NSC) allows for reducing the dimensions of the columns sections. However, this reduction has consequences on the structural performance in case of fire, as smaller cross sections lead to faster temperature increase in the section core. Besides, HSC experiences higher rates of strength loss with temperature and a higher susceptibility to spalling than NSC. The fire performance of a column can thus be affected by selecting HSC over NSC. This research performs a comparison of the fire performance of HSC and NSC columns, based on numerical simulations by finite element method. The thermal and structural analyses of the columns are conducted with the software SAFIR®. The variation of concrete strength with temperature for the different concrete classes is adopted from Eurocode. Different configurations are compared, including columns with the same load bearing capacity and columns with the same cross section. The relative loss of load bearing capacity during the fire is found to be more pronounced for HSC columns than for NSC columns. The impact on fire resistance rating is discussed. These results suggest that consideration of fire loading limits the opportunities for use of HSC, especially when the objective is to reduce the dimensions of the columns sections.

scholarly journals TESTS ON 10.9 BOLTS UNDER COMBINED TENSION AND SHEAR DURING AND AFTER FIRE

2016 ◽  
Author(s):  
Anne K. Kawohl ◽  
Jörg Lange
Keyword(s):  
Bearing Capacity ◽  
Elevated Temperatures ◽  
High Strength ◽  
Preliminary Test ◽  
Test Series ◽  
Fire Performance ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Set Up ◽  
Fire Conditions

Prior investigations of the load bearing capacity of bolts during fire have shown differing behaviour between bolts that were loaded by shear or by tensile loads. The interaction of the two loads has not yet been examined under fire conditions. This paper describes a preliminary test series on the post-fire performance of high-strength bolts of the property class 10.9 under combined tension and shear. The results show that how the bolt is loaded influences the load bearing capacity. It is assumed that this is also true at elevated temperatures. Further, atest set-up for experiments at elevated temperatures and a more detailed test series on the post-fire performance under combined tension and shear is presented.

Study on failure mechanism and end construction influences of double rectangular tube assembled buckling-restrained brace

2016 ◽  
Vol 20 (10) ◽  
pp. 1572-1585 ◽  
Author(s):  
Zi-qin Jiang ◽  
Yan-lin Guo ◽  
Ai-Lin Zhang ◽  
Chao Dou ◽  
Cai-Xia Zhang
Keyword(s):  
Bearing Capacity ◽  
Rational Design ◽  
Failure Modes ◽  
High Strength ◽  
Design Parameters ◽  
Local Pressure ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Buckling Restrained Brace ◽  
Rectangular Tube

The double rectangular tube assembled buckling-restrained brace is a new type of buckling energy consumption buckling-restrained brace. Because of its external restraining members, which are bound by high-strength bolts, its mechanical mechanism is more complicated and its failure modes are more varied. In this study, the double rectangular tube assembled buckling-restrained brace composition and three types of end constructions are introduced in detail. The influences of different design parameters on the performance of double rectangular tube assembled buckling-restrained brace are studied by numerical analysis methods; the possible failure modes and the influence of the end strengthening construction of double rectangular tube assembled buckling-restrained brace are also investigated, and a number of suggestions are proposed to improve this design. This study shows that the pinned double rectangular tube assembled buckling-restrained brace has four types of typical failure modes, namely, overall buckling failure, external end local pressure-bearing failure, bending failure of the extended strengthened core region and bolt threading failure. Rational design can prevent a buckling-restrained brace from losing its load-bearing capacity. In addition, compared with the end strengthening scheme with an external hoop, the end strengthening scheme with a strengthened bench can improve the load-bearing capacity of the double rectangular tube assembled buckling-restrained brace more effectively, and a reasonable design can also save materials.

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