Basalt fiber reinforced asphalt concrete
Patent Information
- Authority / Receiving Office
- TW · TW
- Patent Type
- Patents
- Current Assignee / Owner
- NAT CENT UNIV
- Filing Date
- 2023-07-28
- Publication Date
- 2026-08-01
Smart Images
Figure TWG2TB001903480_001 
Figure TWG2TB001903480_002 
Figure TWG2TB001903480_003
Abstract
Description
Basalt Fiber Reinforced Asphalt Concrete The present invention relates to a basalt fiber reinforced asphalt concrete, and particularly to a basalt fiber reinforced asphalt concrete that enhances the tensile strength and toughness by adding basalt fiber reinforcement bars. In the prior art, asphalt concrete (AC) is made by mixing viscous asphalt mortar with coarse and fine aggregates, sand, and fillers according to a specific proportion in accordance with the asphalt concrete mix design method. Its main use is as the pavement of flexible roads. In Taiwan, AC materials are the mainstream materials for making road pavements. In particular, modified asphalt and stone mastic asphalt concrete have been widely used in the construction, maintenance, and reconstruction projects of the national highway surface layer by the Highway Bureau to cope with the heavy traffic flow on the national highway for more than 20 years. However, as a road pavement, due to the increasing heavy traffic flow, which causes a large amount of repeated rolling on the pavement, and the thermal expansion and contraction effects caused by environmental factors such as climate and rainfall, coupled with the fact that AC materials originally lack tensile strength and toughness, and the viscous strength and tensile strength of AC materials also decrease year by year. Therefore, after many years of use, many块状反射裂缝、车辙变形、横向及纵向于车轮轨迹之疲劳裂缝等 will inevitably appear on the surface layer of the AC pavement. Generally, asphalt sealants are used for repair, but usually the repair effect is limited. Especially in recent years, global warming has led to frequent extreme temperatures, extreme rainfall, and earthquake events, resulting in intensified environmental factors. According to the statistical data of the Federal Highway Administration of the United States, about 36% of the damage to flexible pavements and 24% of the damage to rigid pavements are caused by these extreme environmental factors. In view of the above factors, various engineering designs, including infrastructure projects, have begun to highly require the toughness performance of asphalt concrete to cope with the increasingly harsh usage environment. Therefore, it is necessary to consider more ductile designs in the design of asphalt concrete materials to enhance the tensile strength of asphalt concrete. The research and development of high-toughness asphalt concrete has become an urgent issue. Therefore, in view of the disadvantages existing in the prior art, the inventor has made painstaking attempts and research, and with the spirit of perseverance, finally conceived the "basalt fiber reinforced asphalt concrete" of this case, which can overcome the above disadvantages. The following is a brief description of the present invention. The present invention relates to a basalt fiber reinforced asphalt concrete, and particularly to a basalt fiber reinforced asphalt concrete that enhances the tensile strength and toughness by adding basalt fiber reinforcement bars. Accordingly, the present invention provides a basalt fiber reinforced asphalt concrete, which comprises: an asphalt material having a penetration between 40 and 300 at room temperature and selected from one of asphalt mastic, oil-soluble asphalt, emulsified asphalt, and modified asphalt; aggregate having a first volume percentage between 50% and 80%; basalt fiber reinforcing bars having a second volume percentage between 0.1% and 0.9%; and chemical admixtures for asphalt concrete for adjusting the properties of the basalt fiber reinforced asphalt concrete. Preferably, the second volume percentage is selected from one of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1.0%, 1.5%, 2.0%, 3.0%, and 4.0%. Preferably, the basalt fiber reinforcing bars comprise one of basalt fibers, unsaturated polyester, epoxy resin, vinyl resin, fillers, curing agents, and combinations thereof. Preferably, the basalt fiber reinforcing bars are made by combining basalt fibers as the main material with polymer materials and then through a pultrusion process. Preferably, the basalt fiber reinforcing bars have a length between 1 and 12 mm. Preferably, the basalt fiber reinforced asphalt concrete has an indirect tensile strength greater than 433.8 kPa and thus has better toughness, and the highest CTindex value obtained in the IDEAL-CT test is 4,900. The above invention content aims to provide a simplified summary of the present disclosure to enable readers to have a basic understanding of the present disclosure. This invention content does not disclose the complete description of the present invention, and its intention is not to point out the important / critical elements of the embodiments of the present invention or to define the scope of the present invention. Figure 1 shows the relationship diagram between the porosity and CTIndex of the basalt fiber reinforced asphalt concrete of the present invention; Figure 2 shows the relationship diagram between the load and displacement of the basalt fiber reinforced asphalt concrete of the present invention in the IDEAL-CT test; Figure 3 shows the test result diagram of each group of basalt fiber reinforced asphalt concrete of the present invention in the IDT test; Figure 4 shows the image of the surface crack development of an asphalt concrete flexible road pavement without adding basalt fiber reinforcing bars; and Figure 5 shows the image of the surface crack development of the basalt fiber reinforced asphalt concrete with added basalt fiber reinforcing bars of the present invention as a flexible road pavement. The present invention can be fully understood from the following illustrative embodiments, enabling those skilled in the art to implement it accordingly. However, the implementation of the present invention is not limited to the following embodiments; the drawings of the present invention do not include limitations on size, dimensions, and scale. In actual implementation, the size, dimensions, and scale of the present invention are not restricted by the drawings of the present invention. The term "preferred" used herein is non-exclusive and should be understood as "preferably but not limited to". Any step described or recited in any specification or claim can be executed in any order, not limited to the order stated in the claim. The scope of the present invention should be determined only by the appended claims and their equivalents, and should not be determined by the embodiments of the implementation examples. When the term "comprising" and its variations appear in the specification and claims, it is an open-ended term without a restrictive meaning and does not exclude other features or steps. The research and development of high-toughness asphalt concrete has already been an important topic. The present invention proposes adding basalt fiber reinforcing bars as a reinforcing material to asphalt mastic. After hardening, basalt fiber reinforced asphalt concrete is formed, and the optimal addition amount of basalt fiber reinforcing bars and the toughness design performance of the asphalt concrete pavement structure after adding basalt fiber reinforcing bars are disclosed. The present invention proposes a kind of basalt fiber reinforced bars, which uses basalt fiber as the main material. After further combining with polymer materials such as, for example but not limited to: synthetic resin, unsaturated polyester, epoxy resin, or vinyl resin, etc., fillers, and curing agents and other polymer material matrices, it is then made into a new composite material through an extrusion manufacturing process. After measurement, the basalt fiber reinforced bars proposed by the present invention have the following physical properties. The density of the basalt fiber reinforced bars is between 1.9 and 2.1 g / cm 3 3, which is only about 1 / 4 of that of steel bars (assuming the density of steel bars is 7.8 - 7.9). The tensile strength of the basalt fiber reinforced bars is about 2 - 3 times that of steel bars. The thermal expansion coefficient of the basalt fiber reinforced bars is similar to that of concrete, which can ensure the synchronous deformation of the basalt fiber reinforced bars and concrete. The basalt fiber reinforced bars are composite materials made of non-metallic materials, so they are electrical insulators that never rust, non-magnetic, and have extremely high acid and alkali resistance. They have a relatively high tolerance to the moisture concentration, penetration, and diffusion of carbon dioxide in cement mortar, which can prevent the corrosion of concrete structures in harsh environments, thereby achieving the effect of improving the durability of buildings. Example 1 (A) Composition material formula: (1) Asphalt material: It is preferably the viscosity grade AC-20 or penetration grade 60 / 70 straight-run asphalt mastic provided by Zhongyou or Zhongsu Company, which is the most widely used asphalt material for pavement in highway projects at all levels. The modified asphalt and stone mastic asphalt concrete mastic both use qualified materials meeting the laying standards of expressways. The commonly used polymer modifier for modified asphalt is "Styrene-butadiene-styrene" (SBS). Using this material for mixing and production of polymer modified binder (PMB), it forms a polymer-modified asphalt (PMA) with a dense-graded (Dense-Graded Asphalt Mixture, DGAC) aggregate composition structure. Furthermore, stone matrix asphalt (SMA) is selected. SMA is made of modified asphalt mastic, fiber stabilizer or cement additive to produce stone matrix asphalt. SMA has high durability, resistance to rutting deformation, and can resist studded tires. (2) Coarse and fine aggregates: It is preferably to use six-split stone, three-split stone and fine sand as coarse and fine aggregate aggregates. The test body aggregates use the aggregates with a nominal maximum particle size of 19 mm and a skip grading from Ligang Stream, Pingtung. The coarse aggregates are those retained on the 4.75 mm sieve. (3) Basalt fiber stiffeners: It is preferably to use basalt fiber stiffeners with a length between 1 and 12 mm, which can be regarded as replacing a part of the fine aggregates. The basalt fibers used in the present invention are made by melting basalt ore at high temperature, drawing, cooling and sizing through a high-speed rotating centrifuge. Its thickness is 13 μm and it is in brown filament form. The present invention also incorporates 6 mm basalt fibers as an additional additive. The main component of basalt is 50% (wt%) silicon dioxide, which can improve the high-temperature performance and fatigue resistance of asphalt concrete. Secondly, there are aluminum oxide, ferric oxide, iron oxide, calcium oxide, magnesium oxide, etc., making it have good mechanical properties and chemical stability. The composition components of the basalt fibers used in the present invention are shown in the following table: The physical properties of the basalt fibers used in the present invention are shown in the following table: (4) Mineral filler: The mineral filler used in the present invention is limestone powder as shown in Figures 2-3. Its main component is calcium carbonate and it complies with the ASTM D242 / D242M mineral filler specification. It is required that the mineral filler should not have lumps, clay particles or other organic and harmful substances, and must pass through 0.075 mm (No. 200 sieve). Its specification requirements are shown in the following table: (5) Chemical admixture: The chemical admixture for asphalt concrete refers to the chemical aids added before or during the mixing of asphalt concrete, except for asphalt materials, aggregates and basalt fiber stiffeners, to adjust and change the properties of fresh or hardened asphalt concrete, including the workability, setting time and hardening characteristics of fresh asphalt concrete. The addition of a small amount of chemical admixture is only for improving the mixing efficiency and workability. Generally, it is considered that the addition of chemical admixture cannot enhance the toughness of asphalt concrete. (B) Marshall mix design of asphalt concrete, specimen preparation, and evaluation of toughness design performance (1) Marshall mix design of asphalt concrete: The 19 mm dense-graded asphalt concrete of Marshall mix design is selected for design to confirm the optimum asphalt content. (2) Add basalt fiber stiffeners at volume ratios of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9-% to replace part of the fine aggregate, and confirm the optimum addition amount of basalt fiber stiffeners by Marshall stability value, flow value and indirect tension test. (3) Select the polymer modified asphalt of SBS modified AC-20 as the base asphalt for fiber-reinforced asphalt mastic and stone mastic asphalt concrete. For the fiber-reinforced asphalt mastic, add 3 mm basalt fiber and cellulose fiber at 0.3% of the weight of the mixture added to PMA, and prepare the fiber-reinforced asphalt mastic at a mixing temperature of 180 °C, a mixing speed of 1000 r.p.m. and a mixing time of 30 minutes. (4) Conduct relevant toughness design performance tests with relevant effectiveness tests including indirect tension and IDEAL-CT crack resistance test, etc. (5) At the same time, compare and evaluate the effectiveness with the modified asphalt and stone mastic asphalt concrete that meet the requirements of the Highway Bureau for comparison. Example 2 In this embodiment, basalt fiber stiffeners with 0.1, 0.3, 0.5, 0.7, 0.9, 1.1, and 1.3-% (volume percentage) are preferably added to asphalt concrete to prepare direct tension test specimens (DTT), and a direct tension fatigue test is carried out at -20°C. After measurement, it can be known that when the addition amount of basalt fiber stiffeners is not more than 0.7%, the tensile strength of the final asphalt concrete specimen can be improved; the fatigue test indicates that under the test conditions of a repeated tension to maximum tensile strength ratio of 75%, a loading frequency of 1 Hz, and the same -20°C, the number of repeated loadings is increased from 18,440 times in the pure mastic state to 34,669 times in the basalt fiber reinforced state, an increase of 91%, and the strain at final failure is reduced from 0.0227 to 0.0185, a reduction of 18.5%. Example Three In this embodiment, a dense-graded asphalt concrete with an oil content of 5.0% is preferably selected, and basalt fiber stiffeners with 0, 0.25, 0.50, 0.75, 1.0, 1.5, 2.0-% (volume percentage) are added to the asphalt concrete, and evaluations are carried out by the Marshall effectiveness and ultrasonic wave velocity method. After measurement, it can be known that the dense-graded asphalt concrete with an oil content of 5.0% and a basalt fiber stiffener addition ratio of 0.5% is the best addition ratio for the dense-graded asphalt concrete. As the addition ratio of basalt fiber stiffeners increases, the ultrasonic wave velocity and VMA increase with the increase in the addition amount of basalt fiber stiffeners, showing better toughness. Example Four In this embodiment, basalt fiber stiffeners with 0, 0.2, 0.3, 0.4, and 0.5-% (volume percentage) are preferably added to asphalt concrete. After measurement, it can be known that for dense-graded asphalt concrete, the best addition amount of basalt fiber stiffeners with a length of 3 mm is 0.3% or 0.4%. Compared with the dense-graded asphalt concrete without added basalt fiber stiffeners, its elastic strain energy density can increase by up to 49.5% under the test conditions of -20°C. The measurement results show that after adding basalt fiber stiffeners to dense-graded asphalt concrete, in a low-temperature test environment below 0°C, the damage energy of asphalt concrete can be enhanced, thereby improving the cracking resistance of asphalt concrete. For the performance of the toughness strength of the hardened basalt fiber reinforced asphalt concrete of the present invention, it is preferably to select relevant tests such as indirect tension (IDT) and indirect tension cracking test (IDEAL-CT) resistance cracking test for testing. Indirect Tension (IDT) Test In view of the fact that traditional dynamic fatigue tests are time-consuming and require a large number of test specimens, on-site testing requires a testing method that is not only rapid, convenient, and reliable but also highly accurate. The indirect tensile strength test (Indirect Tensile Strength, IDT) conducted in accordance with ASTM D6931 (2017) is used in the Marshall mix design process to confirm the possibility of tensile cracking in asphalt mixtures. A higher tensile strength indicates better crack resistance. Therefore, the indirect tensile test can be regarded as one of the anti-fatigue damage indicators. Compared with the cylindrical specimens used in dynamic tests, the Marshall specimens of the indirect tensile test are smaller in size. While reducing the consumption, the test time is also significantly reduced. The dynamic test requires repeated loading until the specimen undergoes fatigue failure, while the indirect tensile test loads the specimen to failure at a fixed rate, making it more suitable as a preliminary on-site judgment test. Indirect Tensile Cracking Test (IDEAL-CT) The Indirect Tensile Asphalt Cracking Test (IDEAL-CT) is a method based on fracture mechanics theory to obtain the Cracking Tolerance Index (CTIndex) from the test to determine the anti-cracking performance of asphalt mixtures. The larger the CTIndex value, the better the anti-cracking performance, indicating that the asphalt concrete has better toughness. Generally speaking, CTIndex is more sensitive to Reclaimed Asphalt Pavement (RAP), Reclaimed Asphalt Shingles (RAS), asphalt type, asphalt content, and aging conditions, and has a good correlation with fatigue cracks, reflective cracks, and temperature crack damage in on-site pavements. Generally, only 3 IDEAL-CT laboratory specimens or on-site core specimens are required to obtain a coefficient of variation within 20%. The implementation method of IDEAL-CT is similar to that of traditional indirect tensile tests. It mainly uses an indirect tensile load frame to conduct the test at a loading rate of 50 mm / min at a room temperature of 25°C. It is better to select specimens with a diameter of 150 mm and a height of 62 mm. IDEAL-CT measures the relationship curve between shear force and displacement at 25°C. After calculation, an anti-cracking index CTIndex can be obtained. In recent years, it has been used to evaluate the anti-fatigue and anti-tensile cracking properties of asphalt concrete. The higher the CTIndex, the better its anti-cracking performance and the slower the crack propagation speed. Therefore, IDEAL-CT is an anti-fatigue damage indicator. Figure 1 shows the relationship diagram between the void ratio and CTIndex of the basalt fiber reinforced asphalt concrete of the present invention; the present invention tests the relationship between the shear force and displacement at 25°C, and calculates a CTIndex according to the formula. Through the influence of the void ratio of the basalt fiber reinforced asphalt concrete on the CTIndex, the results are shown in Figure 1. Regardless of the size of its void ratio, its CTIndex is much greater than the standard value of 31. The highest value in Figure 1 can reach 4,900, and the lowest value is still 198. The control group and dry-mixed basalt fibers are both positively correlated. When the void ratio is larger, it means that its compaction degree decreases and the maximum theoretical specific gravity decreases. During the test process, it will be compacted twice, and the deformation of the curve increases accordingly, resulting in an increase in the displacement (l75) at 75% of the peak load after the peak and a decrease in the slope (m75) at 75% of the peak load after the peak. And the CTIndex will also increase accordingly. However, the wet mixing and cellulose fibers are negatively correlated, and their value ranges are lower than those of the dry-mixed basalt fibers. The CTIndex is affected by many parameters, such as: specimen height, specimen diameter, displacement at 75% of the peak load after the peak (l75), slope at 75% of the peak load after the peak (m75), and fracture energy (Gf). Among them, the specimen diameter and specimen height are both made according to the specifications, and their values do not differ much. The largest difference value is m75, and its value range difference is nearly 3 times. When m75 is smaller, it means that the curve is smoother, that is, when cracks appear in the AC, the cracks are less likely to extend, which can be expressed as good crack resistance to extension. The relationship between the CTIndex and m75 shows a negative correlation. When distinguished by fiber type or mixing method, the determination coefficient is even more improved. Among them, the fitting of dry mixing is the closest to the actual situation, and the m75 of wet mixing and cellulose fibers is higher than that of the control group. Figure 2 shows the relationship diagram between the load and displacement of the basalt fiber reinforced asphalt concrete of the present invention in the IDEAL-CT test; the IDEAL-CT load and displacement diagrams of each fiber reinforced SMA of the present invention are overlapped and compared. The results are shown in Figure 2. It can be found that the load of the wet-mixed fiber reinforced SMA (WBF3, WCF) is higher than that of the control group, the deformation is lower than that of the control group, and the curve after the peak is steeper. On the contrary, for the dry-mixed fiber reinforced SMA, the reason may be that the OBC of dry mixing is higher than that of wet mixing, and the designed material height of dry mixing is on the high side, which can effectively slow down the crack propagation speed. In addition, the Indirect Tensile Strength (ITS) measures the ability to resist tensile cracking by IDT. The higher the indirect tensile value, the better the crack resistance. Therefore, ITS is an indicator of fatigue resistance. In this invention, the ITS at 25°C was tested to understand the relationship between the air void content of SMA and ITS. Generally, the trend of ITS decreases as the air void content increases. When the air void content is higher, it means the compaction degree of the specimen is poorer, the effective connection between the mixtures decreases, and the load concentration increases. However, the specimens of wet mixing (WBF3, WCF) show an upward trend, which may be due to the interlocking effect between the aggregates. Figure 3 shows the results of the IDT test for each group of basalt fiber reinforced asphalt concrete of the present invention; Figure 3 is the IDT result of fiber reinforced SMA at 25°C with an air void content of 7±0.5%. For the dry mixing of 3mm and 6mm basalt fibers, their ITS slightly decreases compared to the control group because their OBC increases significantly compared to the control group. However, the ITS of the dry mixing of 12mm basalt fiber BF12 increases, which may be because the confinement of asphalt by 12mm basalt fiber is more significant than that by 3mm and 6mm basalt fibers; the ITS of the specimens of wet mixing (WBF3, WCF) increases. The reasons may be that in addition to their relatively lower OAC, it may also be because wet mixing adds fiber reinforced asphalt mastic at the initial stage of mixing, while dry mixing adds fibers at the later stage of mixing. Wet mixing has more time for adhesion to the aggregates than dry mixing, and its adhesion effect may be relatively better. Overall, as shown in Figure 3, for multiple groups of asphalt concrete reinforced with basalt fibers, from the CG group, BF3 group, BF6 group, BF12 group, CF group, WBF2 group to the WCF group, their ITS are 473.3, 433.8, 446.3, 529.9, 479.7, 523.0 to 509.6 - kPa respectively. Therefore, the indirect tensile strength of the asphalt concrete reinforced with basalt fibers is at least greater than 433.8 kPa. After testing the hardened basalt fiber reinforced asphalt concrete by using the indirect tensile and indirect tensile cracking resistance tests of the present invention, it is measured that the indirect tensile strength of the hardened basalt fiber reinforced asphalt concrete is greater than 433.8 kPa, and the highest value of the CTindex in the IDEAL - CT test is 4,900, which has excellent tensile strength, that is, excellent toughness. Asphalt Mastic Material Property Test First, basic tests such as penetration, softening point, viscosity, and asphalt specific gravity were conducted on the asphalt mastic material properties. It can be seen that after adding fibers to the modified asphalt, its penetration decreased overall, and the penetration was the smallest when 0.3% of fibers was added, indicating that the fiber asphalt was harder; the softening point increased overall, which can reduce the temperature sensitivity of asphalt, and the softening point was the largest when 0.3% of fibers was added, indicating that it effectively prevented sagging; the viscosity increased significantly at low temperatures, and the fiber asphalt with 0.2% had a significant increase at 60°C. At high temperatures, except for the fiber asphalt with 0.2%, the viscosity of the remaining fiber asphalts was still slightly higher than that of the original modified asphalt. Based on the considerations of penetration, softening point, and viscosity at high and low temperatures, 0.3% of the modified asphalt volume was still used as the optimal addition amount. Looking at the above results of softening point, penetration, and viscosity, a fiber content of 0.3% (volume percentage) was selected for analysis. And for the convenience of comparison, regardless of the fiber length, 0.3% was used for the proportion design. It was found that the fibers would absorb some asphalt, resulting in a decrease in the specific gravity after adding fibers to the modified asphalt. In terms of the property proportion design of basalt fibers, the Marshall proportion design method was used as the basis. There were three types: fiber-free stone mastic asphalt concrete, 3mm basalt fiber stone mastic asphalt concrete, and 6mm basalt fiber stone mastic asphalt concrete, combined with asphalt contents of 5.5%, 6%, 6.5%, 7%, and 7.5%. Precise batching was carried out according to the grading design curve of natural aggregate to obtain the stability value, flow value, porosity, voids in mineral aggregate (VMA), and voids filled with asphalt (VFA) of each asphalt content, calculate the optimum asphalt content (OAC), and then estimate the stability value and flow value under the optimum asphalt content. In the present invention, the Superpave IDT test was carried out with basalt fiber addition amounts of 0, 0.3%, 0.5%, and 0.7% for calculation and analysis. The thickness and maximum load of the specimens at 10°C were averaged, and then the displacement gauge readings taken at the maximum load were normalized. The test results showed that from 0.3% to 0.7% of the DCSE The f value gradually increased, and the tensile strength of the asphalt concrete with 0.7% basalt fiber content was the best. For the IDEAL CT test, the basalt fiber addition amounts of 0, 0.3%, 0.5%, and 0.7% were also used for calculation and analysis. The IDEAL CT value was represented by CTindex, and the larger the CTindex, the better the tensile strength. The result showed that the tensile strength of the basalt fiber asphalt concrete with 0.5% was the best. The present invention proposes adding non-corrosive basalt fiber stiffeners to asphalt concrete materials as stiffening materials, which can improve the engineering mechanical properties and toughness design performance of the stiffened asphalt concrete structure, and can further enhance the performance of the stiffened asphalt concrete structure, especially the performance of anti-cracking, earthquake resistance, impact resistance, and durability. The basalt fiber-reinforced asphalt concrete material proposed by the present invention can provide fields that require impact resistance, such as bus lanes, expansion joints, sidewalks, heavy traffic areas, building floors, etc. It can also be used as non-structural cement concrete products, including precast cement floor tiles, interlocking bricks, permeable bricks, and curb stones, etc., to improve their durability. For the basalt fiber-reinforced asphalt concrete proposed by the present invention, due to the addition of basalt fiber reinforcement bars, the restraint force provided by the basalt fiber reinforcement bars can improve the structural capacity, reduce the crack width, maintain the efficiency of longitudinal and transverse stress transfer, and extend the life cycle of the overall overlay pavement. Figure 4 shows an image of the surface crack development of an asphalt concrete flexible road pavement without adding basalt fiber reinforcement bars; Figure 5 shows an image of the surface crack development of the basalt fiber-reinforced asphalt concrete with added basalt fiber reinforcement bars as a flexible road pavement according to the present invention. As shown in Figure 4, for the ordinary asphalt concrete flexible road pavement, after years of use, many "block-shaped" reflective cracks, transverse and longitudinal fatigue cracks at the wheel tracks can be observed on the surface. Although the cracks have been filled with asphalt sealants, the condition of the flexible pavement is not good. After comparing Figure 4 and Figure 5, it can be seen that the crack width control of the flexible road pavement using basalt fiber-reinforced asphalt concrete in Figure 5 is more ideal. After years of use and traffic wear, the condition of the flexible pavement is still quite ideal, and the longitudinal grooving texture on the surface is still quite clear. Under the same traffic volume conditions, the basalt fiber-reinforced asphalt concrete pavement with added basalt fiber reinforcement bars has significantly smaller crack widths. This result is due to the improved toughness of the flexible pavement, that is, higher toughness results in fewer and smaller cracks. And under higher restraint force conditions, even if the asphalt flexible pavement suffers from extreme climates and high temperatures, it can still effectively extend the overall life cycle of the pavement. The above embodiments of the present invention can be combined or replaced with each other arbitrarily, thereby deriving more embodiments, but all are within the scope of protection of the present invention. Further embodiments of the present invention are provided as follows: Embodiment 1: A basalt fiber-reinforced asphalt concrete, which comprises: an asphalt material having a penetration between 40 and 300 at room temperature and selected from one of asphalt cement, oil-soluble asphalt, emulsified asphalt, and modified asphalt; aggregate having a first volume percentage between 50% and 80%; basalt fiber reinforcement bars having a second volume percentage between 0.1% and 0.9%; and chemical admixtures for asphalt concrete for adjusting the properties of the basalt fiber-reinforced asphalt concrete. Example 2: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the penetration, viscosity, type, and grade of the asphalt material comply with the specifications of AASHTO, ASTM, or CNS. Example 3: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the first volume percentage of the aggregate is calculated according to one of the Marshall Method, Hveem Method, Hubbard-Field Method, and Smith Triaxial Method. Example 4: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the asphalt mastic has a penetration of 60 / 70, 60 / 80, 80 / 100, 85 / 100, a viscosity of AC10, AC20, AR-8000, C170, or C320. Example 5: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the basalt fiber-reinforced asphalt concrete is one of dense-graded asphalt concrete, porous asphalt concrete, stone mastic asphalt concrete, gussasphalt concrete, and recycled asphalt concrete. Example 6: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the second volume percentage is selected from one of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1.0%, 1.5%, 2.0%, 3.0%, and 4.0%. Example 7: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the chemical admixtures for the asphalt concrete are selected from one of superplasticizers, air-entraining agents, water-reducing agents, accelerating agents, retarding agents, early-strength agents, water-reducing and retarding agents, water-reducing and early-strength agents, high-performance water-reducing agents, high-performance water-reducing and retarding agents, plasticizers, plasticizing and retarding agents, pigments, corrosion inhibitors, dry shrinkage inhibitors, antifreeze agents, pumping aids, flowing concrete admixtures, special-purpose admixtures, and their combinations. The basalt fiber-reinforced bars comprise one of basalt fibers, unsaturated polyesters, epoxy resins, vinyl resins, fillers, curing agents, and their combinations. Example 8: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the basalt fiber-reinforced bars are made by combining basalt fibers as the main material with polymer materials and then through a pultrusion process. Example 9: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the basalt fiber-reinforced bars have a length between 1 and 12 mm. Example 10: The basalt fiber-reinforced asphalt concrete as described in Claim 1, wherein the basalt fiber-reinforced asphalt concrete has an indirect tensile strength greater than 433.8 kPa and thus has better toughness, and the highest value of CTindex obtained in the IDEAL-CT test is 4,900. The embodiments of the present invention can be arbitrarily combined or replaced with each other, thereby deriving more embodiments, but all are within the scope of protection of the present invention. The scope of protection of the present invention is defined by what is recorded in the patent application scope of the present invention.
Claims
1. A basalt fiber reinforced asphalt concrete comprising: an asphalt material having a penetration of 40 to 300 at room temperature, selected from an asphalt mortar, an oil-soluble asphalt, an emulsified asphalt, and a modified asphalt; an aggregate having a first volume percentage of 50 to 80%; a basalt fiber reinforcing bar having a second volume percentage of 0.5 to 0.9%, a density of 1.9 to 2.1 g / cm³, and a length of 1 to 12 mm; and a chemical admixture for asphalt concrete used to adjust the properties of the basalt fiber reinforced asphalt concrete, wherein the basalt fiber reinforced asphalt concrete has an indirect tensile strength greater than 433.8 kPa and good toughness, and a maximum CTindex value of 4,900 obtained in the IDEAL-CT test.
2. The basalt fiber reinforced asphalt concrete as described in claim 1, wherein the first volume percentage of the aggregate is calculated according to one of the Marshall Method, the Hveem Method, the Hubbard-Field Method, and the Smith Triaxial Method.
3. The basalt fiber reinforced asphalt concrete as described in claim 1, wherein the basalt fiber reinforced asphalt concrete is one of dense-graded asphalt concrete, porous asphalt concrete, stone mortar asphalt concrete, cast-in-place asphalt concrete and recycled asphalt concrete.
4. The basalt fiber reinforced asphalt concrete as described in claim 1, wherein the chemical admixtures used in the asphalt concrete are selected from one of a plasticizer, an air-transfer agent, a water-reducing agent, an accelerator, a retarder, an early-strength agent, a water-reducing retarder, a water-reducing early-strength agent, a high-performance water-reducing agent, a high-performance water-reducing retarder, a plasticizer, a plasticizer and retarder, a pigment, a corrosion inhibitor, a drying shrinkage inhibitor, an antifreeze agent, a pump aid, a fluid concrete admixture, a special-purpose admixture, and combinations thereof, and the basalt fiber reinforcing bar comprises one of a basalt fiber, an unsaturated polyester, an epoxy resin, a vinyl ester resin, a filler, a curing agent, and combinations thereof.
5. The basalt fiber reinforced asphalt concrete as described in claim 1, wherein the basalt fiber reinforcing bar is made by combining basalt fiber as the main material with a polymer material and then producing it through a pultrusion molding process.