Meso-Scale Formulation of a Cracked-Hinge Model for Hybrid Fiber-Reinforced Cement Composites

This study presents a non-linear cracked-hinge model for the post-cracking response of fiber-reinforced cementitious composites loaded in bending. The proposed displacement-based model follows a meso-mechanical approach, which makes it possible to consider explicitly the random distribution and orientation of the reinforcing fibers. Moreover, the model allows for considering two different fiber typologies whereas the cement matrix is modelled as a homogeneous material. The proposed mechanical model combines a fracture-based, stress-crack opening relationship for the cementitious matrix with generalized laws aimed to capture the crack-bridging effect played by the reinforcing fibers. These laws are derived by considering both the fiber-to-matrix bond mechanism and fiber anchoring action possibly due to hooked ends. The paper includes a numerical implementation of the proposed theory, which is validated against experimental results dealing with fiber-reinforced cement composites reinforced with different short fibers. The excellent theory vs. experiment matching demonstrates the high technical potential of the presented model, obtained at a reasonable computational cost.

Download Full-text

Micro-fiber reinforced cement composites. II. Flexural response and fracture studies

Canadian Journal of Civil Engineering ◽

10.1139/l95-079 ◽

1995 ◽

Vol 22 (4) ◽

pp. 668-682

Author(s):

N. Banthia ◽

J. Sheng

Keyword(s):

Crack Opening ◽

Fiber Reinforcement ◽

High Volume ◽

Flexural Behavior ◽

Cement Composites ◽

Fiber Reinforced ◽

Host Matrix ◽

Flexural Response ◽

Reinforced Cement ◽

Resistance Curves

In Part I of this paper, stress–strain curves for micro-fiber reinforced cement-based composites containing high volume fractions of carbon, steel, and polypropylene fibers were obtained. Considerable strengthening, toughening, and stiffening of the host matrix due to micro-fiber reinforcement under both static and impact conditions were reported. In this paper, composites are characterized under an applied flexural load. Both notched and unnotched specimens were tested in four-point flexure; significant improvements in the flexural behavior due to fiber reinforcement were noted. Notched specimens were tested to study the growth of cracks in these composites and to develop a valid fracture criterion. With this objective, crack growth resistance curves and crack opening resistance curves in terms of the stress intensity factor were constructed. The paper recognizes the potential of these composites in various applications and stresses the need for further research. Key words: Portland cement-based materials, fiber reinforcement, fracture toughness, R-curves.

Download Full-text

Nanocelluloses: Natural-Based Materials for Fiber-Reinforced Cement Composites. A Critical Review

Polymers ◽

10.3390/polym11030518 ◽

2019 ◽

Vol 11 (3) ◽

pp. 518 ◽

Cited By ~ 18

Author(s):

Ana Balea ◽

Elena Fuente ◽

Angeles Blanco ◽

Carlos Negro

Keyword(s):

Raw Material ◽

Modulus Of Rupture ◽

Cement Matrix ◽

Future Research ◽

Cementitious Composites ◽

Natural Material ◽

Cement Composites ◽

Fiber Reinforced ◽

Industrial Sectors ◽

Reinforced Cement

Nanocelluloses (NCs) are bio-based nano-structurated products that open up new solutions for natural material sciences. Although a high number of papers have described their production, properties, and potential applications in multiple industrial sectors, no review to date has focused on their possible use in cementitious composites, which is the aim of this review. It describes how they could be applied in the manufacturing process as a raw material or an additive. NCs improve mechanical properties (internal bonding strength, modulus of elasticity (MOE), and modulus of rupture (MOR)), alter the rheology of the cement paste, and affect the physical properties of cements/cementitious composites. Additionally, the interactions between NCs and the other components of the fiber cement matrix are analyzed. The final result depends on many factors, such as the NC type, the dosage addition mode, the dispersion, the matrix type, and the curing process. However, all of these factors have not been studied in full so far. This review has also identified a number of unexplored areas of great potential for future research in relation to NC applications for fiber-reinforced cement composites, which will include their use as a surface treatment agent, an anionic flocculant, or an additive for wastewater treatment. Although NCs remain expensive, the market perspective is very promising.

Download Full-text

Using Acoustic Emission to Quantify Damage in High-Performance Fiber-Reinforced Cement Composites under Cyclically Compressive Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.163-167.2549 ◽

2010 ◽

Vol 163-167 ◽

pp. 2549-2552

Author(s):

Sang Hyun Nam ◽

Young Jae Song ◽

Sun Woo Kim ◽

Hyun Do Yun

Keyword(s):

Acoustic Emission ◽

High Performance ◽

Compressive Load ◽

Cement Matrix ◽

Multiple Cracks ◽

Cement Composites ◽

Fiber Reinforced ◽

Kaiser Effect ◽

High Performance Fiber ◽

Reinforced Cement

High performance fiber-reinforced cement composites (HPFRCCs) show multiple cracks and a limited damage tolerance capability due to the debonding of the fibers of the cement matrix. For practical applications, it is necessary to investigate the fractural behavior of HPFRCCs to understand the mechanism of the microbehavior of a cement matrix containing reinforcing fibers. We have investigated the acoustic emission (AE) signals in HPFRCCs under monotonic and cyclic uniaxial compressive loads. Four types of specimen were tested. The experimental parameters studied were: the type of fiber (polyethylene or polyvinyl alcohol), the hybrid type (with steel cord), and the loading pattern. The data shows that the progress of the damage in HPFRCCs in the compressive mode is characteristic of the type of hybrid fiber and its volume fraction. From the AE data, the second and third compressive load cycles resulted in a successive decrease in the amplitude compared to the first compressive load cycle. In addition, an AE Kaiser effect was observed in HPFRCCs specimens up to 80% of their ultimate strength. These observations suggest that the AE Kaiser effect has potential for use as a new tool to monitor the loading history of HPFRCCs.

Download Full-text

Electromagnetic Interference of Ferrocene-Doped Carbon Fiber-Reinforced Cement Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.261-263.638 ◽

2011 ◽

Vol 261-263 ◽

pp. 638-641

Author(s):

Chuang Wang ◽

Ke Zhi Li ◽

Zhen Jun Wang ◽

Geng Sheng Jiao

Keyword(s):

Carbon Fiber ◽

Electromagnetic Interference ◽

Cement Matrix ◽

Cement Composites ◽

Matrix Composites ◽

Fiber Reinforced ◽

Frequency Range ◽

Maximum Reflectivity ◽

Reinforced Cement ◽

Carbon Fiber Reinforced

The reflectivity of ferrocene-doped carbon fiber-reinforced cement-matrix composites against the electromagnetic radiation was measured in the frequency range of 8-18 GHz for different carbon fiber contents of 0.4, 0.6, 0.89, 1.33, and 1.78 wt% by mass of cement. The ferrocene was doped in 0.89, 1.78, 3.56, 4.89, and 6.27 wt% by mass of cement respectively. The maximum reflectivity reached -4.0 dB when the fiber percentage was 0.89 and the ferrocene was 3.56. The microwave was attenuated by 64 % through reflection. The minimum reflectivity -7.5 dB occurred when the fiber percentage was 1.33 and the ferrocene percentage was 4.89. The microwave was attenuated by 67.5 % through absorption. Prior to the fiber percentage of 0.89 and the ferrocene percentage of 3.56, the reflectivity kept rising.

Download Full-text

Preparation and Performance of Cement Mortar Reinforced by Modified Bamboo Fibers

Polymers ◽

10.3390/polym12112650 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2650

Author(s):

Yang Ban ◽

Wei Zhi ◽

Mingen Fei ◽

Wendi Liu ◽

Demei Yu ◽

...

Keyword(s):

Compressive Strength ◽

Natural Fiber ◽

Drying Shrinkage ◽

Bamboo Fiber ◽

Cement Matrix ◽

Cement Composites ◽

Fiber Reinforced ◽

Freeze Thaw ◽

Reinforced Cement ◽

Bamboo Fibers

This study aims to prepare bamboo-fiber-reinforced cement composites and provide a solution to the issue of poor interfacial adhesion between bamboo fibers and cement matrix. The original bamboo fibers were modified by three moderately low-cost and easy-to-handle treatments including glycerol, aluminate ester, and silane treatments. The performance of the modified bamboo-fiber-reinforced cement composites was evaluated by a series of mechanical and durability tests, including flexural and compressive strength, water absorption, chloride ion penetration, drying shrinkage, freeze–thaw resistance, and carbonization. In addition, the microstructures of composites were characterized using a scanning electron microscope (SEM). The results showed that the composites reinforced with glycerol-modified bamboo fibers had 14% increased flexural strength and comparable compressive strength. From durability perspectives, all treatments showed similar performance in drying shrinkage, whereas aluminate ester treatment was the most effective in terms of impermeability, chloride resistance, freeze–thaw resistance, and carbonization. The results could provide insights to efficient and effective natural fiber treatment to enable better performance of natural-fiber-reinforced cement-based materials.

Download Full-text

High Stpength Fiber Reinforced Cement Composites

MRS Proceedings ◽

10.1557/proc-42-219 ◽

1984 ◽

Vol 42 ◽

Cited By ~ 1

Author(s):

Antoine E. Naamian

Keyword(s):

High Strength ◽

Fiber Reinforced Concrete ◽

Cement Matrix ◽

Cement Composites ◽

Fiber Reinforced ◽

High Fiber ◽

Reinforced Cement ◽

High Matrix ◽

High Strength Fiber ◽

Strength And Ductility

AbstractThe effects of fiber reinforcenent; on the response of high strength fiber reinforced concrete in conmpression, tension and flexure are reviewed. Tradeoffs between the use of high fiber contents to achieve comiposite strength and ductility, and a reduction in matrix porosity to achieve high matrix strength are discussed. Methods used to increase composite strength include application of pressure after casting, addition of fly-ash, silica fumes and or sulerplasticizers to the cement matrix, and mixing high volurite contents of high strength stiff fibers.

Download Full-text

Development and analysis of sponge gourd (Luffa cylindrica L.) fiber-reinforced cement composites

BioResources ◽

10.15376/biores.14.4.9981-9993 ◽

2019 ◽

Vol 14 (4) ◽

pp. 9981-9993

Author(s):

Victor A. Querido ◽

José Roberto M. d’Almeida ◽

Flávio A. Silva

Keyword(s):

Cement Paste ◽

Natural Fiber ◽

Vascular System ◽

Cement Matrix ◽

Cement Composites ◽

Fiber Reinforced ◽

Luffa Cylindrica ◽

3D Network ◽

Sponge Gourd ◽

Reinforced Cement

Sponge gourd (Luffa cylindrica L.) fiber-reinforced cement composites were developed and analyzed. Dried sponge gourd fruit’s fibrous vascular system forms a natural 3D network that can reinforce matrices in composite materials, diverting cracks along the complex array of 3D interfaces between the fibers and the cementitious matrix. To avoid fiber deterioration, the cement paste was modified by incorporating pozzolanic materials. The fibers were mechanically characterized by tensile testing of strips of the 3D natural fiber array and of single fibers extracted from the array. The fibers had an average tensile strength of 140 MPa and an average Young’s modulus up to 28 GPa. Image analysis showed that the fiber spatial distribution inside the 3D network was random. The modified cement paste was characterized by its workability (flow table test) and mechanical behavior (compression and three-point bending tests), with average results of 430 mm, 62.7 MPa, and 6.2 MPa, respectively. Under bending, the cement matrix collapsed after the first crack. The sponge gourd-cement composite manufactured with 1 wt% of fibers showed an average flexural strength of 9.2 MPa (approximately 50% greater than the unreinforced matrix). Importantly, the composite also presented a limited deflection-hardening behavior. These results support sponge gourd’s possible use as reinforcement in cement matrix composites.

Download Full-text

Effects of Moisture on Mechanical and Piezoresistive Properties of Cement Composites containing Carbon Fiber during long age

E3S Web of Conferences ◽

10.1051/e3sconf/202124503061 ◽

2021 ◽

Vol 245 ◽

pp. 03061

Author(s):

Wangyanfeng ◽

Zhaoxiaohua ◽

Zhaoyi ◽

Bianyadong

Keyword(s):

Compressive Strength ◽

Carbon Fiber ◽

Stress Amplitude ◽

Cement Matrix ◽

Gauge Factor ◽

Cement Composites ◽

Matrix Composites ◽

Fiber Reinforced ◽

Reinforced Cement ◽

Carbon Fiber Reinforced

This paper presents a compressive test program designed to determine the mechanical and self-sensing properties of cement-matrix composites containing carbon fiber. Two kinds of mixes with 0.5% and 0.75% carbon fiber （CF） were prepared. The mechanical and piezoresistive properties of the cement-matrix composites were evaluated at 28, 90, 180, 270, and 360 d. The results show that the mechanical properties were enhanced in most cases. However, the compressive strength of carbon fiber reinforced cement-matrix composites decreased compared with the reference mix at the early curing ages, which agrees with the results mentioned in the literature. What is worth to mention, the 360 d compressive strength of carbon fiber reinforced cement-matrix composites reached the same level as that of the reference. Moreover, both negative and positive piezoresistivity were observed during the experiments. The amplitude of piezoresistivity was found to change with the variation of moisture content, and was not directly proportional to the magnitude of the stress. In the elastic stage with smaller stress amplitude, the piezoresistivity amplitude was larger. When the stress amplitude was multiplied, the piezoresistivity change was not synchronous. The gauge factor for the composite with 0.75% CF was higher than that of the composite with 0.5% CF and commercially available strain gauges.

Download Full-text

Development of high performance fiber reinforced cement composites (HPFRCC) for application as a transition layer of reinforced beams

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952014000600005 ◽

2014 ◽

Vol 7 (6) ◽

pp. 965-975 ◽

Cited By ~ 1

Author(s):

V. J. Ferrari ◽

A. P. Arquez ◽

J. B. de Hanai ◽

R. A. de Souza

Keyword(s):

Transition Layer ◽

High Performance ◽

Stress Transfer ◽

Fiber Reinforced Polymers ◽

Cement Matrix ◽

Cement Composites ◽

Fiber Reinforced ◽

Carbon Fiber Reinforced Polymers ◽

High Performance Fiber ◽

Reinforced Cement

This study presents the development and behavior analysis of high performance fiber reinforced cement composites (HPFRCC). The describedmaterials were specifically developed for application as a transition layer: a repair layer that constitutes the stressed chord of reinforcedconcrete beams strengthened in flexure with carbon fiber reinforced polymers (CFRP). Nineteen different composites were produced by thehybridization process, varying the conventional short steel fiber and steel microfiber (manufactured exclusively for this research) contentsto modify the microstructure of the material, thus enhancing the stress transfer process from the cement matrix to the fibers. To analyze theresponse to flexural loading, the composites underwent three point bending tests in notched prism specimens. The response of the materialwas obtained considering strength and tenacity parameters (flexural and fracture). There was evidence of high performance by the composites with a pseudo-hardening behavior.

Download Full-text