Basalt Fibre

One of them is the basalt fiber which is compositionally similar to glass fibers and is produced from naturally occurring basalt rocks.

Basalt Fibers

Boris Mahltig, in Inorganic and Composite Fibers, 2018

9.3Spin Process and Fiber Properties

The basalt fibers can be produced from the melt of basalt stones [23]. In principle two different kinds of basalt fibers are distinguished—staple fibers and filaments [14]. For both types different production methods have been reported. The production of staple fibers is possible directly from small and molten basalt stones. However, these staple fibers possess asymmetrical properties and only a low mechanical performance in mentioned. For industrial production of basalt staple fibers two methods are mentioned: the “Junkers type” and the “centrifugal-multirole system” [14,30]. For advanced applications basalt fibers are produced as filaments. These filaments are produced by a spinneret process. The product of this process consists usually of several hundred monofilaments building up the rovings. This process is quite similar to the production of glass fibers [14]. An example for such basalt monofilament fibers is presented in Fig. 9.3.

For the preparation of fibers from basalt stones, a content of silica of 46% or more is necessary. Only under this precondition it is possible to melt the stone completely without residues, to reach an adequate viscosity for fiber formation, and to gain after freezing a homogenous amorphous phase without crystalline areas [23]. In general, the preparation of basalt fibers can be outlined in following steps: preparation of raw materials, melting of the stones, homogenization of the melt, the spinning of the fibers, and finally the application of the size [14]. Compared to the preparation of melts for glass fiber production, the melting of stones for the basalt fiber production is more challenging. The reason for this is the low thermal conductivity and low transparency for infrared (IR) radiation of basalt fibers. The IR radiation is also named as heat radiation and a material which has a good transparency to heat radiation is warmed homogeneously and liquefy more easily. For this reason, the melting of transparent glass is easier compared to the IR-intransparent basalt. To reach a melt of basalt stones a preheating at 1450°C is described [14]. Another challenge during the preparation of the basalt melt is posed by possible inhomogenities of the natural basalt stones [31]. A sufficient temperature for the spinning of basalt fibers is reported to be in the range of 1350–1420°C [23].

After realizing a homogeneous melt as starting material for the spinning process, the next step is the spinning including the filament formation accompanied by the cooling and solidification of the melt. During this step a problematic crystallization can occur, which can be avoided by thermo-isolation and controlled cooling procedures [26,32]. A fast cooling process leads to a high amorphous basalt fiber, while a slow cooling process increases the crystallization rate of the basalt fiber [32]. If the cooling process is done step by step and not continuously, different types of crystalline phases such as plagioclase, magnetite, and pyroxene can occur [22]. Altogether it should be clear that the exact controlling of temperature of molten basalt and temperature of the cooling is absolutely necessary to obtain basalt fibers of excellent and reproducible properties.

After filament formation and cooling a size is applied to the basalt filaments. This chemical size is of high importance, because it significantly influences the mechanical properties of basalt fibers [23]. The size can be described generally as aqueous solution of various chemicals, which is applied during the spinning process after the filament formation. The first task of the size is to keep the filaments together and improve the mechanical properties. The second task of the size is to improve the attraction of fiber and matrix in fiber-reinforced composite materials [14]. For inorganic fibers such as glass or basalt fibers often sizes containing silane compounds are used. Silane compounds are metalorganic compounds, in which the metal part can bond to the surface of the inorganic fiber, while the organic part has greater attraction to the organic matrix of the fiber-reinforced material [26]. A schematic overview of reaction of silane compounds on basalt fiber surfaces is displayed in Fig. 9.4, while Fig. 9.5 shows some examples of those silane coupling compounds in detail [33].

Besides attaining the above-mentioned properties by the size, other properties are also often aimed such as an improved corrosion stability, antistatic properties, and an improved abrasion stability [26]. A special development is the combination of the size with new materials such as carbon nanotubes (CNTs). A silane treatment of basalt fibers can as well be used to apply CNTs onto the fibers. In this application the silane is used to fix and arrange the CNTs on the basalt fiber surface. In this way modified basalt fibers are used for the preparation of fiber-reinforced materials, which are described as CNT/epoxy/basalt composites and exhibit significant improved fracture toughness [34,35]. Other innovative sizing agents are reported by Wei et al. [36,37]. They described a surface modification of basalt fibers with the so-called hybrid sizings containing nanosilica and epoxy functions.

Such systems can be realized by sol-gel process using tetraethoxysilane (TEOS) and epoxy modified silane compounds, for example, GLYMO shown in Fig. 9.5. The silica particles exhibit diameters of only few nanometers and the epoxy function introduces an enhanced adhesion to the polymer matrix in the final fiber-reinforced material. The main idea is here to realize a compound at the interface of basalt fiber surface to the polymer matrix, which contains an inorganic silica component and an organic epoxy function. The final goal is to improve the adhesion of polymer matrix to the basalt fibers [36,37]. Another aspect of using the size during basalt fiber production is avoiding micro-cracks on the fiber surface by the sizing. By the application of the size the growth of these micro-cracks can be avoided and the tenancy of the fibers can be stabilized [38]. The mechanical stability guaranteed by the size is reported to be absolutely necessary for the production steps like the production of hybrid yarns, weaving, knitting, and the finishing processes. The mechanical forces acting on the fibers during these processes are quite high, so a size giving the fiber a sufficient elasticity and flexibility is necessary [38].

One point to be kept in mind is that if the sizing compounds are made from organic material, then they have a higher thermal sensitivity as the inorganic basalt fibers. It was observed that rovings made from basalt fibers have already lost significant strength after a heat treatment at 300°C [28,39]. For these materials, it was determined that by heat treatment the amount of carbon on the basalt fiber surface can be deleted [28]. Before the heat treatment a significant amount of carbon (15%) was detected on the basalt fiber surface, probably related to an organic sizing agent. By heating process in air, this size is probably burned away and the positive influence of the size on the strength of the rovings is also eliminated [28].

One conclusion from this investigation is that it is necessary to develop sizing agents of high thermal stability especially for use in inorganic fiber with high thermal stability. Only with a thermally stable size, it is possible to take the full benefit of the thermal stability of the inorganic basalt fiber.

Various heat-resistant sizing agents and their applications were investigated by Shayed et al. [40]. They have investigated basalt fiber roving supplied from Asamer Basaltic Fibers GmbH (Austria). These rovings already contain a silane-containing size. Further modification is done by using different heat-resistant polymers applied as sizing agent by dip coating. Two types of sizing agent are applied—a polysilazan (KiON HTT 1800) and a polysiloxane (Silikophen P80/MPA). For testing the rovings are heated with increasing temperature and the testing is carried out according to ISO 3341 standard on the heated fibers [40]. Some results of these mechanical testings are presented in Figs. 9.6 and 9.7.

These investigations lead to the following results. First, the supplied basalt roving already exhibited a mechanical stability at 400°C. Second, by the application of the polysiloxane size the mechanical stability of the basalt roving is significantly improved, probably because the sizing agent glues the basalt fibers together strongly. Third, both additional sizing agents (polysilazane and polysiloxane) lead to improved mechanical properties after heat treatment at 500°C compared to the original basalt roving. However, a thermal treatment at 600°C eliminates mostly the mechanical stability for all the samples [40].

It is concluded that the sizing agents that form a metalorganic polymer film onto the basalt fiber surface act as a protective barrier layer against heat. By this crystallization processes introduced by heat are suppressed and the fiber strength is retained [40]. Further, this polymer film could also act as a barrier layer against oxygen from air. The oxidation of FeO present in the basalt fiber is avoided and the following crystallization is suppressed. The heating up to higher temperatures of 600°C probably also destruct the metalorganic polymer film, so its protective properties for the basalt fibers are diminished.

Altogether, it can be concluded that the sizing agent is an elemental component of basalt fibers, which influences the properties of the basalt fibers significantly. The type of sizing agent used has to be selected according to the demand and the type of application of basalt fibers.

URL: https://www.sciencedirect.com/science/article/pii/B9780081022283000098

Basalt fibers

Jiří Militký, ... Hafsa Jamshaid, in Handbook of Properties of Textile and Technical Fibres (Second Edition), 2018

20.4Influence of temperature on mechanical behavior of basalt fibers

Recent research shows that BFs have good thermal/heat resistance and low humidity absorption. Moisture absorption of BF for 24 h is less than 0.02%, whereas for glass it is 1.7%. Moisture regain of BFs is 1 (Fangueiro, 2011). Industrial glass fibers, especially for a neutral composition, can absorb significant amounts of moisture in humid air. This affects their physical and technical properties and durability and eventually leads to the destruction of fibers. BF absorbency is low and hydroscopicity does not change over time (0.2%–0.3%), due to its chemical composition. BFs have excellent heat and flame resistance, are nonflammable, have no dripping behavior, and have no or very low smoke development (combustion of sizing). Typical thermal properties of basalt and similar high-performance fibers are given in Table 20.7.

Table 20.7. Comparative thermal properties (Chantladze, 2015; Fangueiro, 2011)

Properties Basalt E-glass S2-glass Aramid Carbon
Temperature withstand (°C) −260…+600 −50…+450 50…+300 +205 −50…+500
Maximum application temperature (°C) ∼700–720 ∼380 ∼500 ∼250 ∼400
Melting temperature (°C) 1450 1120 1550 NA NA
Thermal conductivity at 25 ± 5°C (W/m·K) 0.035 0.034–0.04 0.04
Thermal expansion coefficient (ppm/°C) 8.0 5.4

Exposure to higher temperatures will generally promote crystallization and therefore the loss of mechanical characteristics. Militký et al. (2007, 2009) investigated the strength distribution of basalt multifilament roving samples tempered in an oven at temperatures TT = 20, 50, 100, 200, 300, 400, and 500°C in time intervals tT = 15 and 60 min. The 50 samples of strength Pi were collected. These values were recalculated to stress at break values σ i (GPa).

The strength distribution of tempered multifilament roving was nearly Gaussian. The dependence of the roving strength on the temperature exhibited two nearly linear regions. One at low temperature at 180°C with nearly constant strength and one up to the 340°C with a very fast loss of strength. For a description of this dependence the linear spline model was used (Meloun and Militký, 2011). The strengths σ1 for temperature T1 = 180°C and σ2 for temperature T2 = 340°C were computed by the linear least squares. These values and the rate of strength drop are defined as Ds (GPa deg−1):

(20.21)$Ds=\phantom{\rule{0.25em}{0ex}}\left({\sigma }_{1}-{\sigma }_{2}\right)/\left({T}_{2}-{T}_{1}\right)$

are given in Table 20.8.

Table 20.8. Parameters of basalt roving strength dependence on temperature

tT (min) σ1 (GPa) σ2 (GPa) Ds (GPa deg−1)
15
60
1.1070
1.1750
0.343
0.158
0.0048
0.0064

It is clear that increasing the time of tempering leads to the acceleration of structural changes and drops in strength (increasing Ds). The influence of thermal exposition on the shear modulus of the individual basalt filaments removed from roving was also tested (Militký et al., 2009). An apparatus based on the torsion pendulum principle was used. In this apparatus, a length of fiber l0 hung to create a pendulum (moment of inertia M) was subjected to a small shear strain imposed by a small initial twist. The period P and amplitude A of successive oscillations were measured. The shear modulus of circular fiber having radius r is:

(20.22)$G=\frac{2{l}_{0}M{\omega }^{2}}{\text{π}{r}^{4}}$

Frequency of oscillations is in the form:

(20.23)$\omega =\frac{2\text{π}}{P}$

As a pendulum a cylindrical disc of radius R and mass m was used. The corresponding moment of inertia is:

(20.24)$M=\frac{1}{2}m{R}^{2}$

The computed shear moduli for tempering temperatures TT and time of expositions tT are shown in Table 20.9.

Table 20.9. Shear moduli of basalt fibers (Militký et al., 2009)

TT (°C) tT (min) G (GPa)
21.76
100 15 19.43
100 60 12.76
250 15 18.04
250 60 11.34

The shear modulus is comparatively high. The prolongation of tempering leads to a large drop of G.

Hao and Yu (2010) investigated the thermal stability of basalt and glass fibers. In the initial stage, where the temperature range was below 200°C, the mass remained nearly constant. However, mass loss occurred in the temperature range of 200–350°C. In this stage, the mass loss is very fast and significant. It is clearly observed that the fibers were similar in their thermal behavior, but BF has better thermal stability than glass fiber. Also its mass loss is less than that of glass fiber, 1.76% for glass fiber and 0.74 for BF (Fig. 20.9).

BFs show long term thermal stability characteristics. They are resistant to the influence of high temperature for a short time period up to 750°C, whereas for longer exposure the working temperature is in the range from 260 to 700°C, with excursions being possible up to 1000°C. After exposure under 400°C, BF loses only 20%–25% of its initial strength without loss of insulation properties, whilst the strength of E-glass under similar conditions drops more than 40%–45% (Kamenny Vek, 2015; Gilewicz et al., 2013; Milman et al., 1996). The results found for basalt multifilaments were much worse (Militký et al., 2002), see Table 20.8.

Gilewicz et al. (2013) studied the influence of the fatigue bending of textile packages consisting of aluminized basalt woven fabrics, textile inserts, and linings on their structural and thermal insulation properties. Milman et al. (1996) also investigated BF cardboard at a compressive load at 77–293K, for their application as load-bearing insulation for flat-wall cryogenic Dewars with flexible shells. Sim et al. (2005) investigated the thermal stability of basalt, glass, and carbon fibers. The fiber samples were heated in a high-temperature oven for 2 h at 100, 200, 400, 600, and 1200°C. 1200°C temperature is good simulation of a fire event (Fig. 20.10).

Up to 200°C, the variation in strength was neither significant nor clear in tendency. Over 200°C, however, a decrease in strength became distinctive as the heating temperature increased. The reduction was more significant in the carbon and the glass fibers but the BFs retained about 90% of their normal temperature strength up to 600°C. The BFs maintained their shape and seemed to have not lost the mechanical integrity till 1200°C. Li (2011) confirmed this conclusion.

This high thermal stability, i.e., heat resistance, is based on the material characteristics of natural basalt rocks, which nucleate at high temperature. Desirable physical and mechanical properties of fibrous materials are attributed to the homogeneous and fine distribution of crystalline phases. This desired microstructure can be obtained by adding a nucleating agent to some competing fibers such as TiO2, ZrO2, or P2O5. The basalt rocks, however, do not require this but contain a natural nucleating agent (nucleates at high temperature) such as Fe3O4 during the melting process, hence giving advantages over the other fibers, where nucleating agents are necessary to obtain a similar microstructure (Yilmaz et al., 1996).

Van de Velde et al. (2002) investigated the mechanical properties of basalt and glass after 2 h of thermal treatment. They found that basalt can retain its properties over a greater temperature range than glass. At temperatures over 400–500°C, it becomes weaker than glass, but it does retain integrity and still provides protection against heat.

Knotkova et al. (2007) found that the heating of basalt glass up to a temperature higher than 600°C is accompanied by the competitive processes of oxidation of Fe2+ with the evolution of spinel phases ((Mg, Fe)3O4) and the crystallization of a glass matrix (including the formation of a mixture of crystalline silicates and alumosilicates).

URL: https://www.sciencedirect.com/science/article/pii/B9780081012727000201

Life cycle analysis of strengthening concrete beams with FRP

Sebastian George Maxineasa, Nicolae Taranu, in Eco-Efficient Repair and Rehabilitation of Concrete Infrastructures, 2018

24.3.1.4Basalt fibers

Basalt fibers are fabricated by melting crushed basalt rocks at 1400°C and drawing the molten material. Basalt fibers have better mechanical and physical properties than glass fibers, their main advantages being: fire resistance, good resistance to chemically active environments, vibration and acoustic insulation capacity (fib, 2007). The improved production facilities and quality control capacity enable fabrication of basalt fibers with high quality and low variability of properties (Matthys, 2014). Basalt fibers are more expensive than E-glass fibers, but much cheaper than carbon fibers. Some typical properties of basalt fibers are given in Table 24.2, while the architectural forms of these fibers are illustrated in Figs. 24.8–24.11.

URL: https://www.sciencedirect.com/science/article/pii/B9780081021811000241

Technical fibres for heat and flame protection

A.R. Horrocks, in Handbook of Technical Textiles (Second Edition), 2016

8.6.6Basalt fibres

Basalt fibres are obtained from a naturally occurring complex silica/alumina/other oxide basalt rock similar to glass in composition and used as an asbestos replacement. They are available in filament and nonwoven forms with claimed superiority to glass fibres in terms of temperature performance as indicated in Table 8.5. Initially they contained high levels of impurity and were brown in colour, although current versions are bronze. This improved purity in fibres such as Basaltex® (Basaltex NV, Belgium) enables their production as continuous filaments with nominal diameters in the range 9–24 μm. Rovings and chopped fibres are also available. Derived woven fabrics and nonwoven mats are used as fire barriers, thermal insulation, and composite reinforcements.

URL: https://www.sciencedirect.com/science/article/pii/B9781782424659000082

Natural and man-made fibres: Physical and mechanical properties

M. De Araújo, in Fibrous and Composite Materials for Civil Engineering Applications, 2011

Structure and properties

Basalt is a common extrusive volcanic rock, which is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic, containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey. The manufacture of basalt fibre requires the melting of the quarried basalt rock to about 1400 °C, this is then extruded through small nozzles to produce continuous filaments of basalt fibre. There are three main manufacturing techniques, which are centrifugal-blowing, centrifugal-multiroll and die-blowing. The fibres typically have a filament diameter of 9–13 μm, which is far enough above the respiratory limit of 5 μm to make basalt fibre a suitable replacement for asbestos. They also have a high elastic modulus, resulting in an excellent specific tenacity that is three times that of steel. The continuous basalt fibres derived from basalt rock have proven technical characteristics and performance specifications.

Basalt fibres have the following properties:17, 18

fibre diameter (μm): 9

specific gravity: 2.65

high thermal resistance (thermostability) and low flammability

low-strength degradation at temperatures as low as − 200 to 250 °C and as high as + 700 to 900 °C., and of high humidity

operative temperature (°C): –200 to + 900

high thermal and acoustic insulation properties

sound proofing for 400–1800Hz: 80–95%

excellent adhesion to polymer resins and rubbers

relatively high mechanical strength, abrasion resistance and elasticity

tenacity (N/tex): 0.67–0.93

extension at break (%): 3.1

initial modulus (N/tex): 30–35

high dielectric properties

moisture regain (%): 1

low water absorption

high chemical resistance (especially to concentrated acids-based materials)

ecologically clean and non-toxic.

URL: https://www.sciencedirect.com/science/article/pii/B9781845695583500016

Natural fibre rebar cementitious composites

T. Rousakis, in Advanced High Strength Natural Fibre Composites in Construction, 2017

9.4.3Inorganic natural fibre grid: basalt fiber reinforced polymer grid

Basalt fibre grids embedded in cement-based mortar have been used as external confinement of concrete cylinders (Di Ludovico et al., 2010). The application required the patching of a layer of cement-based mortar with a thickness higher than 4 mm. Then the bidirectional basalt fibre grid was preimpregnated with epoxy resin or latex. Finally, a second layer of cement-based mortar was applied with a thickness higher than 4 mm. The experimental results showed a substantial gain in strength and ductility of columns and a gradual failure of the specimens. The results also revealed the need for higher mechanical interaction between the cementitious matrix and the grid.

In a later investigation, Al-Salloum et al. (2012) applied two different cementitious mortars reinforced with basalt textiles to increase the shear strength of reinforced concrete beams. The first mortar was a common cementitious one and the second polymer modified cementitious mortar. External shear strengthening of concrete members is extremely demanding, as it is a bond critical application, while the developed inclined tensile strains are very low prior to shear cracking formation. Therefore successful external strengthening requires a high bond between the mortar and concrete substrate, as well as a high interaction between the mortar matrix and basalt textile grid. The experimental results of the study were very promising, as the shear capacity of the beams was substantially raised. Retrofits with polymer-modified cementitious mortar matrix presented a higher shear strength increase.

Larrinaga et al. (2013) investigated, both experimentally and analytically, the behavior of mortar reinforced with basalt textiles under direct tension. Basalt textile was covered with a bitumen coat to improve the bond with the mortar. The mortar matrix presented multiple cracking, denoting a good bond of the system in multiple layers of basalt textiles (Fig. 9.5). Also the model provided a satisfactory prediction of the whole stress-strain behavior of the cementitious composite.

Basalt fibre grids are widely applied in masonry structures. In Balsamo et al. (2014), basalt textile grids were embedded in lime-based mortar of very low strength and bonded externally on both sides of masonry panels. Masonry panels consisting of uncoursed masonry were representative of existing buildings in L'Aquila, Italy. Also, a yellow tuff masonry panel was included. The shear performance of the panels was remarkably enhanced. The failure mode of strengthened masonry panels was far more ductile. External seismic strengthening of masonry buildings with cementitious basalt grids may provide a reliable, efficient and sustainable alternative. Further analytical research is required to accurately quantify the enhancement of this technique with respect to the retrofit system, the reinforcement layout and the masonry type. Efficient analytical tools will allow for the retrofit of a large number of existing masonry structures with damages (environmental deterioration, inadequate construction techniques and materials, design for gravity loads only) or high seismic vulnerability. A basalt grid with an inorganic matrix provides high strength-to-weight ratio, low influence on global structural mass, corrosion and fatigue resistance, easy handling and installation and negligible architectural impact (Balsamo et al., 2014).

Basalt textile reinforcements are also included (together with carbon, glass and steel ones) in the study by Ascione et al. (2015). The authors proposed a method for the qualification of externally bonded FRCM systems, based on combined direct tension and shear bond tests. The maximum stress and mode of failure of the FRCM system are estimated with shear bond tests. Then the qualification strain is estimated more reliably with direct tension tests, given the failure stress (from shear bond tests). The study presents the characteristic three-stage behavior of FRCMs under tension, as well as their typical force-slip behavior for different modes of failures. The study considers cement or lime mortars as matrices and modern bricks or historic bricks or tuff units as substrates.

URL: https://www.sciencedirect.com/science/article/pii/B9780081004111000091

Low velocity impact properties of natural fiber-reinforced composite materials for aeronautical applications

Muthukumar Chandrasekar, ... Z. Leman, in Sustainable Composites for Aerospace Applications, 2018

14.4.4Effect of hybridization

Hybridization is defined as the mixing of two or more natural fibers or natural/synthetic fibers in intra-ply or inter-ply combination in a common matrix to tailor its mechanical properties, and to suit the need for structural applications [48,49]. The purpose of hybridization is to obtain a new type of material which can retain the advantages of its constituents [16].

14.4.4.1Natural-synthetic fiber-reinforced hybrid composite

Introduction of basalt fibers into carbon-epoxy composite lead to an increase in absorbed impact energy of the hybrid composite compared to the carbon-epoxy composite [50]. Ahmed et al. indicated that damage resistance capability of the low velocity impacted jute fiber-based isothalic PE composite can be enhanced by the introduction of glass fibers into the composite to form a hybrid composite. However, the absorbed energy was higher for jute–isothalic PE composite than the hybrid composite [51]. Pandita et al. showed a similar improvement in drop weight impact properties with the use of glass–epoxy composite in the top and bottom along with jute fiber–epoxy in the core [52]. Shahzad found that hybrid hemp–glass fiber-based composite showed improvement in damage tolerance up to a 15 J impact energy. At a 4 J impact energy, hybrid composites lost 30% of their intrinsic strength and stiffness, compared to a 70% loss by hemp fiber-based composites [53]. From the results of Davoodi et al., it can be concluded that the impact strength of the hybrid kenaf–glass mat epoxy-based composite increased significantly due to the addition of 5% polybutylene terephthalate (PBT) additive, but the impact strength was lower for the hybrid composite than that of the commercial glass mat thermoplastic (GMT) [54]. Morye and Wool found that the absorbed impact energy depends on the fiber volume fraction of flax–glass ratio, and the fiber arrangement/side exposed to impact in the soyabean oil-based composite [55]. Petrucci et al. indicated that the peak load of the drop weight impacted hybrid composite glass–hemp–flax–basalt–epoxy resin was higher for flax-based hybrid composite than that of glass-based hybrid composite, and increased in magnitude with higher impact energy [56]. Venkatasubramanian and Raguraman concluded that the impact strength of an ortho-phthalic acid resin-based composite can be tailored by changing the fiber volume fraction of abaca–banana–glass fibers, and through hybridization [18].

Sarasini et al. subjected basalt–carbon fabric-based epoxy laminate to quasi-static mechanical tests, and found that an inter-ply configuration with the alternate layers of basalt and carbon fabric has better impact energy absorption capability [57]. Similar results on improved impact energy absorption and damage tolerance have been reported by Sarasini et al. on the inter-ply combination of basalt–aramid fabric-based epoxy composite [58]. Wang et al. studied the effects of fiber arrangement, namely intra-ply (fiber yarns placed next to each other in the same layer) and inter-ply (fiber yarns placed in different layers) in three-dimensional woven basalt–aramid–epoxy hybrid composite. According to them, the inter-ply hybrid composite exhibited superior properties such as lower peak load and higher specific energy absorption in both the weft and warp direction than the intra-ply hybrid composite [59]. According to Dehkordi et al., basalt–nylon fiber content and impact energy had a significant influence on the absorbed energy, elastic energy, and damping index of the epoxy-based composite [16]. A similar increase in peak load and absorbed impact energy was reported for a carbon–flax hybrid composite with a higher impact energy level, as reported by Sarasini et al. [60]. Likewise, Nisini et al. reported that the peak load and damage degree of the hybrid composite containing carbon–flax–basalt fiber in an epoxy matrix can be tailored by altering the fiber stacking sequence and fiber orientation in the hybrid composite [61].

14.4.4.2Natural-natural fiber-reinforced hybrid composite

According to Jawaid et al., hybridization of oil palm empty fruit bunch (EFB) with jute fibers in epoxy composite leads to a higher decrease in the Izod impact strength than the pure EFB–epoxy composite, but it is higher than the cured neat epoxy resin [62]. Similarly, a decrement in absorbed charpy impact energy of the hybrid abaca–jute–epoxy composite compared to the individual fiber-based composite was reported by Ramnath et al. [63]. However, according to Fragassa et al., both the peak force and absorbed energy of the flax–basalt hybrid composite showed a marked increase with an increase in impact energy of the drop weight, while the impact properties of the hybrid composite showed only a small difference in magnitude compared to the individual fiber-based composite [64]. As per Dhakal et al., hybridization of hemp fiber with basalt fibers leads to enhanced damage tolerance of the hybrid composite subjected to quasi-static tests [65]. Kumar et al. studied the impact properties of hemp–epoxy, basalt–epoxy, and hybrid basalt–hemp–epoxy composite. Absorbed energy, impact force, and impacted energy were better for the hybrid composite than that of the hemp–epoxy composite. Absorbed energy and damage degree increased as the material processing temperature was increased for all three types of composite [20].

URL: https://www.sciencedirect.com/science/article/pii/B9780081021316000141

Composites: Manufacture and Application

Bethany Middleton, in Design and Manufacture of Plastic Components for Multifunctionality, 2016

3.2.2.4Basalt Fibers

Similarly to glass fibers, basalt fibers are made by drawing a fiber from a molten material. However, in this case, the melt is 100% basalt with no further constituent ingredients or additives. Therefore, they are considered considerably more ecofriendly than carbon fibers. They have a long history of engineering application use since the 1920s. Basalt fibers are typically 9–13 μm and have a higher strength and stiffness than glass fibers and are not as expensive as carbon. They are mainly used in civil applications needing superior properties to glass but despite being not as widely used as either glass or carbon appear to offer considerable further multifunctional potential uses in conjunction with other materials.

URL: https://www.sciencedirect.com/science/article/pii/B978032334061800003X

Fibrous insulation materials in building engineering applications

X. Lu, M. Viljanen, in Fibrous and Composite Materials for Civil Engineering Applications, 2011

10.4.2Fire insulators

Because of their unique structure, based on quartz or basalt fibers in combination with non-decomposable binder for example, fibrous materials are capable of withstanding high heating temperatures for a long time (Zverev et al., 2008). Therefore, fibrous heat-resistant materials, especially their composites (Bai & Keller, 2007), are widely used in practice in various high-temperature technologies such as fire insulators in buildings.

Bai et al. (2007) developed models for assembling the material properties of fibrous composites, thermo-chemical and thermo-mechanical models to predict the thermal and mechanical responses of the composites under elevated and high temperatures. The post-fire mechanical properties of fibrous materials have also been evaluated widely (e.g. Pering et al., 1980; Springer, 1984). Haddad et al. (2008) evaluated the bond behavior between fiber-reinforced concrete and reinforcing steel rebars under elevated temperatures. Results showed that the use of fibers minimized the damage in the steel–concrete bond under elevated temperatures and hence the reduction in bond strength.

In high performance concrete, the addition of polypropylene fibers is widely used as an effective method to prevent explosive spalling and its efficiency was investigated by Liu et al. (2008).

Some experimental studies and results on the fire behavior of glass fiber-reinforced polymer load-carrying slabs for building applications were presented in a series of papers (Keller et al., 2005; 2006a; 2006b).