scholarly journals Structural Design Calculation of Basalt Fiber Polymer-Modified RPC Beams Subjected to Four-Point Bending

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3261
Author(s):  
Yafeng Gong ◽  
Jianxing Yang ◽  
Xin He ◽  
Xiang Lyu ◽  
Hanbing Liu
Keyword(s):  
Bearing Capacity ◽  
Structural Design ◽  
Basalt Fiber ◽  
Fiber Surface ◽  
Bending Moment ◽  
Reinforced Concrete Beam ◽  
Design Calculation ◽  
Normal Section ◽  
Four Point Bending ◽  
Practical Engineering

In this paper, a basalt fiber surface was treated with coupling agent KH-550 and hydrochloric acid, and the basalt fiber polymer-modified active powder concrete (RPC) material was prepared. There are significant differences in material composition and properties between basalt fiber polymer-modified RPC and ordinary concrete, and the structural design calculation (cracking moment and normal section bending bearing capacity) of an ordinary reinforced concrete beam is no longer applicable. Thus, mechanical parameters such as displacement and strain of reinforcement basalt fiber polymer-modified RPC beams subjected to four-point bending were tested. The excellent compressive and tensile strengths of basalt fiber polymer-modified RPC were fully utilized. The tensile strength of basalt fiber polymer-modified RPC in the tensile zone of the beam was considered in the calculation of normal section bending bearing capacity of reinforcement basalt fiber polymer-modified RPC beams. The results showed that the measured values of the cracking moment and ultimate failure bending moment of reinforcement basalt fiber polymer-modified RPC beams were in good agreement with the calculated values. The established formulas for cracking moment and normal section bending bearing capacity can provide references for the design of reinforcement basalt fiber polymer-modified RPC simply supported beam and promote the wide application of basalt fiber polymer-modified RPC materials in practical engineering.

The Principle and Calculation Method of Carbon Fiber Reinforcement for Tunnels and Underground Structures

2011 ◽  
Vol 94-96 ◽  
pp. 1247-1251
Author(s):  
Hong Ke Pan ◽  
Jiang Chun Hu ◽  
Lin De Yang
Keyword(s):  
Carbon Fiber ◽  
Bearing Capacity ◽  
Calculation Method ◽  
Underground Structure ◽  
Fiber Reinforcement ◽  
Bending Moment ◽  
Design Calculation ◽  
Underground Engineering ◽  
Single Section ◽  
Carbon Fiber Reinforcement

There will emerge cracks or damage due to the action of rock pressure or its own shortcomings and low strength for the lining structure in tunnel or underground engineering, especially at the places of excessive bending moment and tensile stress because of bias pressure where concrete will be pull apart for the deficiency of strength even to cause leakage and durability insufficient. Conventional maintenance and reinforce methods are time-consuming and laborious, and the effect is also not ideal. It is simple, timesaving and having a significant and lasting effect to use carbon fiber reinforcement method. This paper studied structure’s failure mechanism and on the basis of that the principle of fiber-plate reinforcement from the angle of structural plastic development, then studied the improvement of structure’s mechanical character and the change of design calculation method for single section of underground structure with carbon fiber plates by using the research method of plane-strain. At the same time, the typical model of integral failure for single section was analyzed and the calculation method and formulae of bearing capacity and reinforcing steel bars were deduced, which remedied the shortfall in the design specification for concrete structure. In the end, by comparing the calculation results of structure with fiber plates and that with not fiber plates based on engineering example, the conclusion that structure’s bearing capacity and capability of resistance to deformation had obvious improvement was obtained.

Research on Mechanical Properties of Reinforced Concrete (RC) Beams for the Corrosion by Sea Water

2014 ◽  
Vol 507 ◽  
pp. 317-321
Author(s):  
Xia Zhou ◽  
Xi Kang Yan
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beam ◽  
Mechanical Performance ◽  
Sea Water ◽  
Vertical Section ◽  
Reinforced Concrete Beam ◽  
Rc Beams ◽  
Normal Section ◽  
Initial Strength

By way of the soaking and drying cycle test on the different mix proportions vertical section of 10 pieces of RC beams suffered artificial sea water (ASW) corrosion under0,35,70,105,140 times of dry-wet cycles, the compared result of exerting pressure test of these beams under simply supporting were investigated. The law about the changes of the mechanical performance for RC beams with different mix proportions under different time periods for suffering corrosion of dry-wet cycles was as follows: The resistibility to ASW corrosion for the concrete specimens with various water cement ratio (various initial strength) are different;The characters of normal section failure for RC beams attacked by sea water are about the same as that for ordinary RC beam; Along with the extension of the time for seawater attack, the bearing capacity for normal section of RC beams varies wave upon wave. The specimens attacked by seawater for about 35 times of corrosion cycle achieve minimum bearing capacity. KEYWORDS: reinforced concrete beam; sea water corrosion; bearing capacity;

scholarly journals Field Experiment Research of the Polycystic Aeration Bolt: Model Design and Anchorage Mechanism

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Wen Xiang Peng ◽  
Ming Kai Xu ◽  
Yi Fan Chen ◽  
Zheng Hao Chen ◽  
Zhuo Yang
Keyword(s):  
Bearing Capacity ◽  
Structural Design ◽  
Soft Soil ◽  
Test Results ◽  
Foundation Pit ◽  
Design Scheme ◽  
Pull Out ◽  
Practical Engineering ◽  
New Type ◽  
Engineering Cost

As a new type of bolt, the polycystic aeration bolt has a broad application prospect in soft soil area; however, its design and production are still in the stage of constant exploration and improvement. From the perspective of bolt material and engineering cost, the important components of the polycystic aeration bolt were analyzed by combination with the existing bolt models, and a new structural design scheme of a kind of polycystic aeration bolt which can be used in practical engineering was presented in this paper. Then, the stress and failure mode of this bolt were discussed, and the theoretical equation of the bearing capacity was derived by using the elastic-plastic theory. In addition, the assembly and fabrication technology of this bolt in practical foundation pit engineering was described in detail. Finally, the field pull-out test of the polycystic aeration bolt was carried out, and the test results were compared with those of the conventional grouting bolt, which indicated that this new bolt has a greater advantage in bearing capacity than the conventional grouting bolt, verifying the feasibility of the structural design scheme of the polycystic aeration bolt proposed in this paper.

scholarly journals Behavior Characteristics of Single Batter Pile under Vertical Load

2021 ◽  
Vol 11 (10) ◽  
pp. 4432
Author(s):  
Jiseong Kim ◽  
Seong-Kyu Yun ◽  
Minsu Kang ◽  
Gichun Kang
Keyword(s):  
Bearing Capacity ◽  
Relative Density ◽  
Model Test ◽  
Ground Surface ◽  
Bending Moment ◽  
Vertical Position ◽  
Vertical Load ◽  
Behavior Characteristics

The purpose of this study is to grasp the behavior characteristics of a single batter pile under vertical load by performing a model test. The changes in the resistance of the pile, the bending moment, etc. by the slope of the pile and the relative density of the ground were analyzed. According to the results of the test, when the relative density of the ground was medium and high, the bearing capacity kept increasing when the angle of the pile moved from a vertical position to 20°, and then decreased gradually after 20°. The bending moment of the pile increased as the relative density of the ground and the batter angle of the pile increased. The position of the maximum bending moment came closer to the ground surface as the batter angle of the pile further increased, and it occurred at a point of 5.2~6.7 times the diameter of the pile from the ground surface.

scholarly journals An Experimental Study of Horizontal Bearing Capacity of Vertical Steel Floral Tube Micropiles with Double Grouting

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Kaiyang Wang ◽  
Yanjun Shang
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Slip Surface ◽  
Bending Moment ◽  
Shear Capacity ◽  
Soil Reinforcement ◽  
Scale Model ◽  
Soil Pressure ◽  
Floral Tube ◽  
Grouting Pressure

This paper examines the performance of a novel technology, vertical steel floral tube micropiles with double grouting. It is the combination of micropile technology and double grouting technology. A large-scale model tank was applied to impart horizontal bearing capacity, and the slope soil pressure and flexural performance of the micropile were investigated under four experimental conditions. The peak grouting pressure during the double grouting process was defined as the fracturing pressure of the double grouting, and it was positively correlated to the interval time between first grouting and secondary grouting. Compared with traditional grouting, double grouting increased the horizontal bearing capacity of the single micropile with the vertical steel floral tube by 24.42%. The horizontal bearing capacity was also 20.25% higher for the structure with three micropiles, compared with a 3-fold value of horizontal sliding resistance. In the test, the maximum bending moment acting on the pile above the sliding surface was located 2.0–2.5 m away from the pile top, and the largest negative bending moment acting on the pile below the slip surface was located 4.0 m away from the pile top. The ultimate bending moment of the single pile increased by 12.8 kN·m with double grouting, and the bending resistance increased by 96.2%. The experimental results showed that the double grouting technology significantly improved the horizontal bearing capacity of the micropile with the steel floral tube, and the soil reinforcement performance between piles was more pronounced. Also, the shear capacity and the flexural capacity were significantly improved compared with the original technology.

Analysis on Deformation of Pre-Splitting Steel Reinforced Concrete Beams Strengthened by Prestressed CFRP

2011 ◽  
Vol 243-249 ◽  
pp. 929-933
Author(s):  
Na Ha ◽  
Lian Guang Wang ◽  
Shen Yuan Fu
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Steel Reinforced Concrete ◽  
Cfrp Sheets ◽  
Deformation Curves ◽  
Prestressed Cfrp Sheets ◽  
Theoretical Results

In order to improve the bearing capacity of SRC which is related with deformation and stiffiness, SRC beams should be strengthened by CFRP. Based on the experiment of six pre-splitting steel reinforced concrete beams strengthened with (Prestressed) CFRP sheets, the deformation of beams are discussed. Load-deformation curves are obtained by the experiment. Considering the influence of intial bending moment on SRC beams, the calculated deformation formulas of SRC beams strengthened by (Prestressed) CFRP are deduced. The results showed that the load-deformation curves of normal and strengthened beams respectively showed three and two linear characteristics. The theoretical results which calculated by the formulas of deformation are well agreement with the experimental results.

Experimental Investigation on the Effect of Arm Length on Accuracy of Torque Wrench

2016 ◽  
Vol 853 ◽  
pp. 216-220 ◽  
Author(s):  
You Gang Peng ◽  
Yong Wang
Keyword(s):  
Experimental Investigation ◽  
Structural Design ◽  
Bending Moment ◽  
Theoretical Solution ◽  
Calibration Laboratory ◽  
Moment Measurement ◽  
Torque Wrench ◽  
Actual Use ◽  
Good Agreement

Experiments were carried out to investigate the effect of arm length on the accuracy of two typical conventional torque wrenches, namely, setting type torque wrench (STW) and indicating type torque wrench (ITW). The experiment results demonstrate that the measurement values of STW rises rapidly with decreasing arm length while measured torque of ITW shows irrelevant to arm length. Theoretical solution with respect to STW shows quite good agreement with experiment results. Irrelevance of arm length regard to ITW may be attributable to compensation of bending moment measurement due to proper arrangement of circuit and structural design. In order to conduct a proper assessment at a calibration laboratory or ensure its reliability with reference to actual use conditions, a torque wrench should be used by a customer at the loading point as recommended.

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