scholarly journals Planning Research on Application of Nanomaterial Technology in Disaster Prevention and Reconstruction

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jun Shao ◽  
Huihui Yan ◽  
Haosheng Xu
Keyword(s):  
Seismic Performance ◽  
Concrete Strength ◽  
Fiber Reinforced Concrete ◽  
Silica Fiber ◽  
Disaster Prevention ◽  
Nano Silica ◽  
Ordinary Concrete ◽  
Urban Disaster ◽  
Fiber Concrete ◽  
Pva Fiber

An earthquake causes a huge loss of life and property. After an earthquake, many buildings are seriously damaged or collapsed. On the one hand, it is necessary to make full use of nanomaterials technology to improve seismic strength during reconstruction; on the other hand, scientific planning is needed to reduce pollution, carbon emissions, and energy consumption. This paper mainly studies the application of nanomaterial technology in disaster prevention and reconstruction. Through a series of planning safeguard measures, the overall seismic performance of the city is improved in order to provide theoretical guidance and technical support for disaster prevention and reconstruction. This paper mainly introduces the stress analysis of frame joints after earthquake and the planning of urban disaster prevention and reconstruction. In addition to the different types of concrete materials (ordinary concrete, nano silica fiber concrete, PVA fiber concrete), the fixed amount of water, superplasticizer, reinforcement, sand, and gravel, the concrete strength grade is C30. Then, three kinds of concrete frame joints are tested under low cycle cyclic loading to compare the seismic performance of the three kinds of concrete. The experimental results show that the fuzzy evaluation of urban disaster prevention and reconstruction planning has been carried out for 6 communities in this city. Among them, 4 communities are qualified and 2 communities are unqualified. Therefore, it is necessary to focus on seismic reinforcement or carry out urban planning research again. Compared with ordinary concrete, the bearing capacity and ductility coefficient of nano silica fiber concrete and PVA fiber concrete are increased by 37.8% and 15.6%, respectively. It is proved that the seismic performance of nano silica fiber reinforced concrete is far better than that of ordinary concrete.

scholarly journals Experimental Investigation on the Effect of Rubber Powder on Mechanical Properties of PVA Fiber Concrete

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Linling Ma ◽  
Bin Wang ◽  
Lei Zeng ◽  
Yunfeng Xiao ◽  
Heng Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Damping Ratio ◽  
Strength Loss ◽  
Fiber Reinforced Concrete ◽  
Test Results ◽  
Rubber Powder ◽  
Fiber Concrete ◽  
Pva Fiber ◽  
Optimal Mixing ◽  
Sem Test

To verify the damping improvement by replacing partial sand with rubber powder in the concrete process, this study investigated the effects of the rubber powder (5%, 10%, 15%, and 20%) on the mechanical properties and micromechanism of polyvinyl alcohol (PVA) fiber-reinforced concrete. In addition, in order to discuss its damping performance, free vibration test was conducted. Microstructure analyses were conducted by the scanning electron microscope (SEM) test. These results indicated that, as the content of the rubber powder increased, the damping ratio increased, and the compressive strength decreased, but this strength loss can be effectively controlled by adding PVA fiber. The rubber powder with a volume content of 5% and PVA with a mass of 2.4 kg/m3 were the most optimal mixing to balance the strength and damping requirement. According to the SEM test results, the rubber powder was beneficial to improve the damping ratio of PVA concrete, but it aggravated its interface defects.

Experimental Studies of Reinforced Concrete and Fiber-Reinforced Concrete Beams with Short-Term and Long-Term Loads

2019 ◽  
Vol 968 ◽  
pp. 227-233 ◽  
Author(s):  
Stepan Neutov ◽  
Maryna Sydorchuk ◽  
Mykola Surianinov
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Experimental Studies ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Short Term ◽  
Ordinary Concrete ◽  
Fiber Concrete ◽  
Steel Fiber Concrete

Experimental studies of the stress-strain state of reinforced concrete and fiber-reinforced concrete beams under short-term and long-term loads were carried out. The tests were carried out on three series of beams of different types - from ordinary concrete, steel fiber concrete and combined section, when the lower zone of the beam with a height of0.5his made of steel fiber concrete, and the upper one is made of ordinary concrete. During short-term loading, the load was applied in steps with a 10-minute exposure at each step to failure or to a predetermined level of a continuously acting load. In the interval between the steps, the process of cracking was tracked. After reaching a given level of loading, the load was fixed and maintained unchanged with a spring cassette for 300 days. Deformations were measured using strain gauges and dial gauges. Deflections and relative deformations of the extreme upper and extreme lower fibers for three types of beams are determined. It has been established that stabilization of deflections in beams from steel fiber concrete occurs much earlier (100 days) than in beams made of ordinary concrete (175 days). Studies have shown that the beams of ordinary concrete in the process of long-acting load lowered the carrying capacity by 5.5%. The bearing capacity of steel concrete beams, in contrast, increased by 7.6%.

Effect of Nanomaterials on Mechanical Properties of Fiber Reinforced Concrete

2020 ◽  
Vol 852 ◽  
pp. 59-69
Author(s):  
Zhao Liang Sheng ◽  
Yan Fu Duan ◽  
Duo Tian Xia ◽  
Olivier Thierry
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Silicon Dioxide ◽  
Mechanical Strength ◽  
Experimental Analysis ◽  
Concrete Strength ◽  
Basalt Fiber ◽  
Fiber Reinforced Concrete ◽  
Basalt Fibers ◽  
Fiber Concrete

In order to explore the application of nanomaterials in fiber concrete, in this research, the effect of nanomaterials SiO2 on the basalt fiber concrete was studied with experimental analysis methods. The variation values of mechanical properties were calculated respectively. On this basis, the influences of silicon dioxide nanometer and basalt fibers on the mechanical properties of nanosilica silicon dioxide nanometer basalt fiber concrete were studied. Different contents of silicon dioxide nanometer were added to concrete, different contents of basalt fibers were added to concrete, and both were added to concrete. The results showed that adding silicon dioxide nanometer could modify building concrete and significantly improve the mechanical properties of concrete. the increase of silicon dioxide nanometer content of nanomaterials, the strength of concrete showed a trend of first rising and then falling. When silicon dioxide nanometer content was 1.2%, the mechanical strength was the largest. As the contents of basalt fiber increase, concrete strength showed a trend of first increasing and then decreasing. When basalt fiber content was 3kg/m3, it was the optimal content and the concrete strength was the largest. And the mechanical properties of the concrete mixed with silicon dioxide nanometer and basalt fibers were significantly improved.

Compound and Engineering Application of Fiber Reinforced Concrete with Low Shrinkage

2014 ◽  
Vol 941-944 ◽  
pp. 873-876
Author(s):  
Jian Fen Li ◽  
Shu Jin Li
Keyword(s):  
Reinforced Concrete ◽  
Experimental Research ◽  
Water Storage ◽  
Engineering Application ◽  
Fiber Reinforced Concrete ◽  
Quality Monitoring ◽  
Test Results ◽  
Storage Test ◽  
Fiber Concrete ◽  
Pva Fiber

On the basis of experimental research about PVA fiber concrete, combined with the technology measures such as expansive belt, construction quality monitoring, the jointless design and construction is successfully carried out for an industry tank. The water storage test results showed that impervious performances can meet the requirements of specification and achieved desired effects.

scholarly journals Research on bond–slip performance between pultruded glass fiber-reinforced polymer tube and nano-CaCO3 concrete

2020 ◽  
Vol 9 (1) ◽  
pp. 637-649 ◽  
Author(s):  
Zhan Guo ◽  
Qingxia Zhu ◽  
Wenda Wu ◽  
Yu Chen
Keyword(s):  
Bond Strength ◽  
Concrete Strength ◽  
Fiber Reinforced Polymer ◽  
Glass Fiber Reinforced Polymer ◽  
Bond Slip ◽  
Ordinary Concrete ◽  
Bond Performance ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Push Out

AbstractThe article describes an experimental study on the bond–slip performance between the pultruded glass fiber-reinforced polymer (GFRP) tube and the nano-CaCO3 concrete. Taking the nano-CaCO3 concrete strength and GFRP tube thickness as primary parameters, nine specimens were designed and tested to study the influence of these parameters on the bond strength of the specimens. Besides, three specimens filled with the ordinary concrete were also tested by using the push-out tests to make comparisons with the bond performance of the specimens filled with nano-CaCO3 concrete. A total of four push-out tests were conducted on each specimen. The experimental results indicate that there are two types of axial load–slip curves for each specimen in four push-out tests. Moreover, comparison of the results of the push-out tests in the same direction shows that the bond failure load of the specimen decreases with the increase in the number of push-out tests. Based on the analysis of the test results, it is shown that the bond performance between the GFRP tube and the nano-CaCO3 concrete is better than that between the GFRP tube and the ordinary concrete. Furthermore, as the nano-CaCO3 concrete strength increases, the bond strength of the specimens decreases, indicating that the concrete strength has a negative effect on the bond strength. When the nano-CaCO3 concrete strength is relatively smaller (C20), the bond strength of the specimens decreases with the increase in the thickness of the GFRP tube. However, when the nano-CaCO3 concrete strength is relatively larger (C30 and C40), the bond strength of the specimens increases as the thickness of the GFRP tube increases.

Review of Strength and Failure Criteria for Concrete After Freeze-Thaw Damage

2012 ◽  
Vol 253-255 ◽  
pp. 456-461
Author(s):  
Yan Fu Qin ◽  
Bin Tian ◽  
Gang Xu ◽  
Xiao Chun Lu
Keyword(s):  
Normal State ◽  
Concrete Strength ◽  
Failure Criteria ◽  
Concrete Durability ◽  
Freezing And Thawing ◽  
Normal Concrete ◽  
Strength Criteria ◽  
Freeze Thaw ◽  
Ordinary Concrete ◽  
Concrete Failure

Frost resistance research is one of the important subject of concrete durability, however strength criteria is an important part of the study of mechanical behavior of concrete. So far, about concrete failure criteria are almost for normal concrete, which the domestic and overseas scholars have comparative detailed research in every respect to it, and to freeze-thaw damage of concrete but few research. Based on the summary of the existing ordinary concrete strength and failure criteria in normal state and after freeze-thaw damage，this paper have a brief comment of failure criteria on concrete after freeze-thaw damage. For later research about concrete strength and failure criteria under freezing and thawing cycle provide the reference.

Experimental Studies of Fiber-Reinforced Concrete under Axial Tension

2021 ◽  
Vol 1038 ◽  
pp. 323-329
Author(s):  
Zlata Holovata ◽  
Daria Kirichenko ◽  
Irina Korneeva ◽  
Stepan Neutov ◽  
Marina Vyhnanets
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
Fiber Reinforced Concrete ◽  
Load Application ◽  
Fiber Reinforced ◽  
Large Aggregate ◽  
Second Stage ◽  
Axial Tension ◽  
Deformation Properties ◽  
Fiber Concrete

The design of a stand for testing concrete and fiber-reinforced concrete specimens-"eight" in tension, which provides axial load application and minimizes the effect of stress concentration at the ends of the specimen. The design of the stand is such that the distance between the axis of load application and the central hinge is 108 cm, and between this hinge and the axis of the test specimen is 21 cm, as a result of which the load transferred to the specimen is 5.143 times greater than the applied one. At the first stage of testing, it was found that the optimal characteristics of the fiber-concrete mixture is a matrix with a large aggregate ≤ 10 mm with 1.0% fiber reinforcement. At the second stage, the ultimate strength of fiber-reinforced concrete for axial tension was determined - 1.28 MPa when reinforced with wave fiber and 1.37 MPa when reinforced with anchor fiber, which amounted to 4.1% and 4.4% of compressive strength, respectively. It was also found that concrete reinforced with anchor fiber has higher deformation properties than concrete reinforced with wave fiber.

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