Basalt Fibers in Modified Whisker Reinforced Cementitious Composites

The calcium carbonate whisker (CW) and basalt fiber are gaining popularity due to its enhanced mechanical properties in composites. Also, the short and long fibers provide bridging role and resistance against cracking from micro- to macro-scale, respectively. The usage of long and short hybrid basalt fiber along with addition of CW in cement-based composites is still a research gap. In this work, experimental behavior of CW basalt hybrid fiber reinforced mortar is considered with various content and length (3 mm, 6 mm, 12 mm, and 20 mm) of hybrid basalt fibers. In addition to this, synergy performance index is determined to quantitatively evaluate the positive interaction of hybrid basalt fiber in cementitious materials. The strengthening effect of whiskers and basalt fibers are also studied using scanning electron microscopy. The CW with various basalt fiber contents having different length of hybrid basalt fiber is used. It was found that the four various length of hybrid basalt fiber together with CW in cement mortar exhibited enhanced compressive, flexural, and split tensile strength than that of pure mortar and single length basalt fiber reinforced cementitious mortar. The results of synergy performance index showed similar trend with the experimental results. The strengthening effect caused by step by step crack arresting mechanism was also observed in cementitious material.

An Experimental Study on the Effect of Nanomaterials and Fibers on the Mechanical Properties of Polymer Composites

This study aims to explore the tensile and impact properties (tensile strength, modulus of elasticity, and impact strength) of polypropylene (PP)-based nanocomposites reinforced with graphene nanosheets, nanoclay, and basalt fibers. The response surface methodology (RSM) with Box–Behnken design (BBD) was adopted as the experimental design. An internal mixer was used to prepare compounds consisting of 0, 0.75 and 1.5 wt% graphene nanosheets, 0, 10 and 20 wt% basalt fibers, and 0, 3 and 6 wt% nanoclay. The samples were prepared by a hot press machine for mechanical testing. The tensile tests were run to determine the tensile strength, and modulus of elasticity, and the Charpy impact tests were performed to assess the impact strength. It was found that the addition of basalt increased the tensile strength, modulus of elasticity, and impact strength by 32%, 64% and 18%, respectively. Also, the incorporation of the low-weight graphene nanosheets increased the tensile and impact strength by 15% and 20%, respectively, Adding graphene nanosheets generally improved the modulus of elasticity by 66%. Similarly, the addition of nanoclay improved the tensile strength by 17% and increased the modulus of elasticity by 59%, but further addition of it decreased the impact strength by 19%. The values obtained by this experiment for the mechanical property were roughly close to the data yielded from desirability optimization.

Effects of Fiber Diameter on Crack Resistance of Asphalt Mixtures Reinforced by Basalt Fibers Based on Digital Image Correlation Technology

It is now more popular to use basalt fibers in the engineering programs to reinforce the crack resistance of asphalt mixtures. However, research concerning the impact of the basalt fiber diameter on the macro performance of AC-13 mixtures is very limited. Therefore, in this paper, basalt fibers with three diameters, including 7, 13 and 25 μm, were selected to research the influences of fiber diameter on the crack resistance of asphalt mixtures. Different types of crack tests, such as the low temperature trabecular bending test (LTTB), the indirect tensile asphalt cracking test (IDEAL-CT), and the semi-circular bend test (SCB), were conducted to reveal the crack resistance of AC-13 mixtures. The entire cracking process was recorded through the digital image correlation (DIC) technique, and the displacement cloud pictures, strain, average crack propagation rate (V) and fracture toughness (FT) indicators were used to evaluate the crack inhibition action of the fiber diameter on the mixture. The results showed that the incorporation of basalt fiber substantially improved the crack resistance, slowed down the increase of the displacement, and delayed the fracture time. Basalt fiber with a diameter of 7 μm presented the best enhancement capability on the crack resistance of the AC-13 mixture. The flexibility index (FI) of the SCB test showed a good correlation with V and FT values of DIC test results, respectively. These findings provide theoretical advice for the popularization and engineering application of basalt fibers in asphalt pavement.

Effect of conditions and parameters of drawing on strength and surface condition of basalt continuous fibers

Basalt continuous fibers are used in the development of new composite materials. The influence of various factors on the strength and formation of the surface microstructure of basalt continuous fibers is considered. An experimental determination of tensile strength was performed and the surface condition of continuous andesite-basalt fibers with a diameter of 8 to 10 μm fibers was investigated. It is established that the strength of fibers, among other factors, is influenced by the conditions of their production, which are determined by the drawing parameters: the production temperature, the level of melt in the feeder and the winding speed. The effect of production temperature on the strength of the fibers was the greatest. It was found that the fibers obtained at a production temperature of 1450 °C had a strength of 24—28% greater than that of the fibers obtained at a production temperature of 1400 °C. The separate influence of other parameters of drawing, the level of melt in the feeder and the winding speed on the strength of the fibers is less significant. A qualitative relationship between the state of the surface of the fibers and the conditions of their production at different parameters of formation. The greatest influence on the change in the state of the surface of the fibers has the temperature of fiber production. It is established that the surface of the fibers obtained at a production temperature of 1450 °C is more homogeneous with a small number of visible defects. On the other hand, on the surface of the fibers, which are obtained at a production temperature of 1400 ºC, there is a large number of defects. There is also an increase in the defect of the surface of the fibers, which are obtained at low levels of melt in the feeder and the winding speed. Keywords: continuous fibre, surface structure, strength, cooling rate, production temperature, winding speed, melt level in the feeder.

Environmental Efficiency Aspects of Basalt Fibers Reinforcement in Concrete Mixtures

Modern building materials must fulfill not only functional performance criteria but also reduce the environmental impact accompanied by their production. Within the past decades, fiber-reinforced materials have been found to be promising and durable materials that can be utilized in various fields. Among a wide range of reinforcement types, basalt fibers have been introduced as an alternative to broadly used steel fibers. As informed by the available literature, benefits linked with less energy-intensive production indicate a very good potential application of this material in terms of functional properties and, at the same time, a reduction in environmental burden. However, only a very limited amount of information is available on the actual impact of using basalt fibers in terms of environmental impact. In order to fill this gap, the present study describes, using Life Cycle Assessment, the environmental impacts associated with the production of basalt fibers. In order provide a more reliable and coherent overview, an analysis combining functional and environmental indicators was performed. The presented results reveal that the use of basalt reinforcement provides a significantly lower environmental intensity per strength unit, especially in the case of compressive and flexural strength.