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 ◽  
...  

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.

Author(s):  
Vera V. Galishnikova ◽  
Alireza Heidari ◽  
Paschal C. Chiadighikaobi ◽  
Adegoke Adedapo Muritala ◽  
Dafe Aniekan Emiri

Relevance. The load on a reinforced concrete slab with high strength lightweight aggregate concrete leads to increased brittleness and contributes to large deflection or flexure of slabs. The addition of fibers to the concrete mix can improve its mechanical properties including flexure, deformation, toughness, ductility, and cracks. The aims of this work are to investigate the flexure and ductility of lightweight expanded clay concrete slabs reinforced with basalt fiber polymers, and to check the effects of basalt fiber mesh on the ductility and flexure. Methods. The ductility and flexural/deflection tests were done on nine engineered cementitious composite (expanded clay concrete) slabs with dimensions length 1500 mm, width 500 mm, thickness 65 mm. These nine slabs are divided in three reinforcement methods types: three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm (first slab type); three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm plus dispersed chopped basalt fiber plus basalt fiber polymer (mesh) of cells 2525 mm (second slab type); three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm plus dispersed basalt fiber of length 20 mm, diameter 15 m (third slab type). The results obtained showed physical deflection of the three types of slab with cracks. The maximum flexural load for first slab type is 16.2 KN with 8,075 mm deflection, second slab type is 24.7 KN with 17,26 mm deflection and third slab type 3 is 32 KN with 15,29 mm deflection. The ductility of the concrete slab improved with the addition of dispersed chopped basalt fiber and basalt mesh.


2020 ◽  
Vol 198 ◽  
pp. 01010
Author(s):  
Duo Wu

Concrete structure will be corroded under acid rain scouring and soaking for a long time, which has a great influence on its durability life. In order to further study the damage characteristics of fiber reinforced concrete under acid rain erosion, the formation mechanism of acid rain and its influence on the corrosion and deterioration of concrete and fiber materials were analyzed in this paper. Taking basalt fiber concrete as an example, the characteristics such as porosity, compressive strength and mechanical indexes were studied and analyzed. Moreover, the reasons for the optimal fiber content was briefly analyzed. The results show that the inner structure of basalt concrete mixed with 0.1% fiber was the most stable and the corrosion resistance was the most satisfying.This conclusion has certain reference significance for the corrosion damage research of fiber reinforced concrete.


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Yang Lv ◽  
Xueqian Wu ◽  
Mengran Gao ◽  
Jiaxin Chen ◽  
Yuhao Zhu ◽  
...  

Basalt fiber has arisen new perspectives due to the potential low cost and excellent mechanical performance, together with the use of environmental friendly coir can be beneficial to the development of sustainable construction. In this study, a new composite structure called basalt fiber reinforced polymer (BFRP) tube encased coconut fiber reinforced concrete (CFRC) is developed. The 28-day compression strength of the plain concrete is about 15 MPa, which represents the low-strength poor-quality concrete widely existing in many old buildings and developing countries. Three types of BFRP tubes, i.e., 2-layer, 4-layer, and 6-layer, with the inner diameter of 100 mm and a length of 520 mm, were prepared. The plain concrete (PC) and CFRC were poured and cured in these tubes to fabricated BFRP tube confined long cylindrical beams. Three PC cylindrical beams and 3 CFRC cylindrical beams were prepared to be the control group. The four-point bending tests of these specimens were carried out to investigate the enhancement due to the BFRP tube and coir reinforcement. The load-carrying capacity, force-displacement relationship, failure mode, and the cracking moment were analyzed. Results show that both BFRP tube confined plain concrete (PC) and BFRP tube confined CFRC have excellent flexural strength and ductility, and the inclusion of the coir can further enhance the ductility of the concrete.


2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Dao-yuan Wang ◽  
Jia-suo Qi ◽  
Guang-yao Cui ◽  
Yanling Yang ◽  
Jie Chang

Adding fiber can improve the brittleness of plain concrete. Compared with plain concrete, basalt fiber-reinforced concrete has the advantages of strengthening, toughening, and crack resistance. Compared with steel fiber-reinforced concrete, basalt fiber-reinforced concrete has better construction performance. Basalt fiber concrete is a type of inorganic material with environmental protection and high mechanical properties, which has an important mechanical advantage for controlling the deformation of the soft surrounding rock tunnel. Through the indoor model test of mechanical behavior of reinforced concrete and basalt fiber-reinforced concrete lining, the bearing characteristics of basalt fiber-reinforced concrete lining was studied. The results show that, compared with reinforced concrete, the initial crack load of basalt fiber-reinforced concrete is increased by 20%; the toughness of lining structure is enhanced by adding basalt fiber, and the lining can still bear large bending moment and deformation after the initial crack appears; after the initial crack appears, the bearing characteristic curve of reinforced concrete lining rises slowly and converges rapidly; the bearing characteristic curve of basalt fiber-reinforced concrete lining rises slowly, and there is no sign of convergence when it reaches 2 times of initial crack load. For the soft surrounding rock tunnel, it is necessary to seal the rock surface as early as possible, provide support as soon as possible, and have a certain deformation capacity. Basalt fiber-reinforced concrete can better meet these needs.


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