scholarly journals Effect of Polypropylene Fibers on Self-Healing and Dynamic Modulus of Elasticity Recovery of Fiber Reinforced Concrete

Fibers ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 9 ◽  
Author(s):  
Adham El-Newihy ◽  
Pejman Azarsa ◽  
Rishi Gupta ◽  
Alireza Biparva
Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 104
Author(s):  
Fernando A. N. Silva ◽  
João M. P. Q. Delgado ◽  
António C. Azevedo ◽  
Tahlaiti Mahfoud ◽  
Abdelhafid Khelidj ◽  
...  

Early deterioration of reinforced concrete foundations has been often reported in recent years. This process is usually characterized by an extensive mapping cracking process on concrete surfaces that results from several types of Internal Swelling Reaction (ISR). In this paper, a real case study of a tall reinforced concrete building with a severe deterioration process installed in its deep foundations is discussed. Laboratory tests were performed in concrete drilled cores extracted from a deep pile cap block 19 years after the beginning of construction. Tests to assess the compressive strength, the static and the dynamic modulus of elasticity, the gas permeability, and electron microscopy scanning to find out the primary mechanism responsible for the deterioration observed during in situ inspections. Chemical alterations of materials were observed in concrete cores, mainly due to Delayed Ettringite Formation (DEF), which significantly affected the integrity and durability of the structure. Dynamic modulus of elasticity showed to be a better indicator of damage induced by ISR in concrete than compressive strength. Procedures to strengthen the deteriorated elements using prestressing proved to be an efficient strategy to recover the structural integrity of pile caps deteriorated due to expansions due to ISR.


2014 ◽  
Vol 584-586 ◽  
pp. 1304-1308 ◽  
Author(s):  
Sheng Ji Jin ◽  
Zhong Liang Li ◽  
Jian Zhang ◽  
Yan Ling Wang

The concrete composite material with basalt fiber as enhancing system in it has a lot of advantages ,including excellent mechanical properties , high temperature resistant, resistant to acid and alkali, low cost, environmental protection materials and resistance production process. It has been applied to the field of construction project. Damage of northern environment of freezing and thawing on the properties of the composite material has become a new hot issue. In order to study the characteristics of basalt fiber reinforced concrete as building composite materials in the process of freezing and thawing, this research uses the freeze-thaw cycle test to carry out the performance study on change of dynamic modulus of elasticity and quality loss of basalt fiber concrete. We use basalt fiber volume content of 0, 0.1%, 0.2% and 0.3% respectively of four groups of concrete specimens as the research object, to carry them on the freezing-thawing resisting performance test research. Research results show that the performance of dynamic modulus of elasticity and quality loss of basalt fiber concrete in freezing and thawing process is obviously better than the plain concrete. The dosage of 0.3% basalt fiber concrete freezing-thawing resisting performance is the best in the four groups of concrete samples.


Concrete is hard but liable to break easily. Hybrid fiber reinforced concrete offers several economical and technical benefits. The use of fibers extends its possibilities. The hybridization of different types of fibers may play important roles in arresting cracks and thus achieve high performance of concrete. The main reason for adding glass ,steel and polypropylene to improve the ductility of concrete.The present research work is aimed at studying, the deep beam using three different types of fibers such as glass 0.3%, steel 0.75% & 1% and polypropylene fibers 0.3% were added to volume of concrete. The mix design has been arrived based on IS code method for M20 grade of concrete. An investigation is carried out to evaluate the fresh Properties and mechanical Properties of Hybrid Fiber Reinforced Concrete (HFRC). The result shows that hybrid fiber reinforced deep beams achieved better performance than the ordinary RC deep beam under application of load.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Longlong Niu ◽  
Shiping Zhang

This paper presents an experimental study on the performance of cracked ultra-high-performance fiber-reinforced concrete (UHPC) exposed to dry-wet cycles of 3.5% NaCl solution under the temperature of 60°C. The results show that the wider the crack, the higher the corrosion degree of steel fibers embedded in UHPC, and the deeper the chloride ion diffusion on both sides of the crack. With the increase of dry-wet cycles, the flexural strength of precracked UHPC first decreases and then increases, and the lowest flexural strength was observed in 60 dry-wet cycles. Although self-healing is hard to cease the corrosion of steel fibers, it can relieve the corrosion of steel fibers and improve the flexural strength exposed to 100 dry-wet cycles.


2021 ◽  
Vol 53 (2) ◽  
pp. 210209
Author(s):  
Aris Aryanto ◽  
Berto Juergen Winata

This paper focuses on comparing the behavior of RC tension members with and without the addition of polypropylene fibers at various corrosion levels. Eight cylindrical tensile specimens were tested to evaluate their tension-stiffening and cracking behavior. The content of polypropylene fiber added into the concrete mix was the main variable (0.25%, 0.50%, 0.75%, and 1.0% of total volume). The corrosion level was varied from slight (5%), medium (10%) to severe (30%) and, like the other variables, applied only to 1.0% polypropylene fiber-reinforced concrete (PFRC) specimens. The test results showed that the fiber addition significantly increased the tension-stiffening effect but was largely unable to reduce the effect of bond degradation caused by corrosion. Moreover, the addition of polypropylene fibers was able to improve the cracking behavior in terms of crack propagation, as shown by smaller crack spacing compared to the specimen without fiber addition at the same corrosion level.


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