Chloride penetration in shrinkage-compensating cement concretes

Shi, Weizhuo; Najimi, Meysam; Shafei, Behrouz

doi:10.1016/j.cemconcomp.2020.103656

Cited by 23 publications

(5 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formation of cracks expedites the transport of corrosive agents, mainly chloride ions and CO 2 , into concrete, endangering the durability of reinforced concrete structures [ 193 , 194 , 195 , 196 , 197 ]. Several methods have been suggested to help concrete withstand shrinkage-induced cracks, including the use of shrinkage-compensating cement [ 198 , 199 , 200 ] and/or fibers. When fibers are incorporated into a concrete mixture, even in low dosages, they can withstand the induced tensile stresses, preventing the formation of cracks that can endanger the life-cycle performance and durability of concrete structures.…”

Section: Shrinkagementioning

confidence: 99%

State-of-the-Art Review of Capabilities and Limitations of Polymer and Glass Fibers Used for Fiber-Reinforced Concrete

et al. 2021

Self Cite

View full text Add to dashboard Cite

The concrete industry has long been adding discrete fibers to cementitious materials to compensate for their (relatively) low tensile strengths and control possible cracks. Extensive past studies have identified effective strategies to mix and utilize the discrete fibers, but as the fiber material properties advance, so do the properties of the cementitious composites made with them. Thus, it is critical to have a state-of-the-art understanding of not only the effects of individual fiber types on various properties of concrete, but also how those properties are influenced by changing the fiber type. For this purpose, the current study provides a detailed review of the relevant literature pertaining to different fiber types considered for fiber-reinforced concrete (FRC) applications with a focus on their capabilities, limitations, common uses, and most recent advances. To achieve this goal, the main fiber properties that are influential on the characteristics of cementitious composites in the fresh and hardened states are first investigated. The study is then extended to the stability of the identified fibers in alkaline environments and how they bond with cementitious matrices. The effects of fiber type on the workability, pre- and post-peak mechanical properties, shrinkage, and extreme temperature resistance of the FRC are explored as well. In offering holistic comparisons, the outcome of this study provides a comprehensive guide to properly choose and utilize the benefits of fibers in concrete, facilitating an informed design of various FRC products.

show abstract

Section: Shrinkagementioning

confidence: 99%

State-of-the-Art Review of Capabilities and Limitations of Polymer and Glass Fibers Used for Fiber-Reinforced Concrete

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…As summarized in Table 3, the developed mixtures were tested for flow, compressive strength, and flexural strength, following the details presented in the past studies 26–29 . Specifically, the flow was measured using a flow table modified following ASTM C143.…”

Section: Mixture Proportions and Test Plansmentioning

confidence: 99%

“…As summarized in Table 3, the developed mixtures were tested for flow, compressive strength, and flexural strength, following the details presented in the past studies. [26][27][28][29] Specifically, the flow was measured using a flow table modified following ASTM C143. The flow test was in accordance with the standard, except for skipping the 25 drops of the table, which were not necessary because the developed mixtures were self-consolidating.…”

Section: Mixture Proportions and Test Plansmentioning

confidence: 99%

Flexural response characteristics of ultra‐high performance concrete made with steel microfibers and macrofibers

Karim

Shafei

2021

Structural Concrete

Self Cite

View full text Add to dashboard Cite

Ultra‐high performance concrete (UHPC) is increasingly used for various engineering applications, owing to its superior strength properties. Such properties, however, can be accompanied by workability issues, especially if the dosage of steel fibers is significantly increased. As a potential solution, this study explored the use of a combination of steel microfibers and macrofibers through a holistic experimental testing program. This was to understand the effects of steel fiber combinations on the workability and flexural strength of various UHPC mixtures. The microfibers were investigated for five different dosages from 1.0% to 3.0% (with an increment of 0.5%). In parallel, two mixtures were prepared with a 2.0% dosage of macrofibers in the form of twisted wire and hooked fibers. At the next stage, six additional mixtures were prepared with a combination of microfibers and macrofibers of various dosages. Further to the measurements extracted from the workability and flexural strength tests, digital image correlation (DIC) analyses were employed to obtain firsthand information about the widths and depths of cracks observed in the flexural specimens tested under an increasing load. The outcome of this study showed how a combination of microfibers and macrofibers can contribute to improving the flexural response characteristics of UHPC, especially without having to increase the dosage of steel fibers to the ranges that can adversely affect the mixture's workability.

show abstract

“…Additionally, microfibers are found to be useful in reducing shrinkage‐induced effects. This is critical, especially for plastic shrinkage, during which concrete is still in the fresh state and has not gained an adequate strength 11–16 . On the other hand, macrofibers are most beneficial in enhancing the concrete's postpeak strength properties through bridging macrocracks and enabling the concrete matrix to offer enhanced ductility and impact resistance 17–24 .…”

Section: Introductionmentioning

confidence: 99%

“…This is critical, especially for plastic shrinkage, during which concrete is still in the fresh state and has not gained an adequate strength. [11][12][13][14][15][16] On the other hand, macrofibers are most beneficial in enhancing the concrete's postpeak strength properties through bridging macrocracks and enabling the concrete matrix to offer enhanced ductility and impact resistance. [17][18][19][20][21][22][23][24] Given the complementary contributions of micro and macrofibers to concrete, a transition to hybrid fiberreinforced concrete (FRC) mixtures, which contain both micro and macrofibers, has received growing attention.…”

mentioning

confidence: 99%

Mechanical properties of hybrid fiber‐reinforced concretes made with low dosages of synthetic fibers

Kazemian

Shafei

2022

Structural Concrete

View full text Add to dashboard Cite

Recent advances made in concrete fibers have made them one of the concrete's recommended ingredients, mainly to eliminate the drawbacks associated with the weakness of cementitious materials, such as concrete, in tension. The addition of fibers, however, introduces extra cost and labor requirements, while selecting an appropriate choice and dosage of fibers has still remained a standing question. To address the outlined issues, the current study investigates the development of fiber‐reinforced concrete (FRC) mixtures with a focus on achieving superior mechanical properties with a low dosage of synthetic fibers. For this purpose, three choices of macrofibers were examined. The investigations spanned four dosages of each macrofiber mixed with three dosages of a microfiber included to ensure adequate resistance to early‐age, shrinkage‐induced strains. The experiments conducted on the developed hybrid FRC mixtures systematically measured workability, as well as compressive, splitting tensile, and flexural strength properties. The test results were then paired with the micro‐scale monitoring of the bond between individual macrofibers and the concrete matrix through scanning electron microscope images. The outcome shed light on how each of the macrofibers of choice contributed to improving the FRC's mechanical properties. This paved the way to benefit from a minimum dosage of them to achieve the expected structural response, while avoiding crack formation and propagation in various applications.

show abstract

Chloride penetration in shrinkage-compensating cement concretes

Cited by 23 publications

References 28 publications

State-of-the-Art Review of Capabilities and Limitations of Polymer and Glass Fibers Used for Fiber-Reinforced Concrete

State-of-the-Art Review of Capabilities and Limitations of Polymer and Glass Fibers Used for Fiber-Reinforced Concrete

Flexural response characteristics of ultra‐high performance concrete made with steel microfibers and macrofibers

Mechanical properties of hybrid fiber‐reinforced concretes made with low dosages of synthetic fibers

Contact Info

Product

Resources

About