Multi-class fiber-carbide slag composite modified asphalt and preparation method thereof

Abstract

The invention provides multi-class fiber-carbide slag composite modified asphalt and a preparation method thereof, and aims to solve the technical problem that the service life of an existing asphalt pavement is not expected due to insufficient pavement performance and frequent high and low temperature diseases. The composite modified asphalt is prepared from the following raw materials in parts by weight: 100 parts of matrix asphalt, 1-2 parts of sweet potato seedling straw fibers, 1-2 parts of bagasse fibers and 2-3 parts of carbide slag. The composite modified asphalt provided by the invention is excellent in pavement performance, simple in preparation process, low in production cost, non-toxic and harmless in raw materials, capable of enhancing the high-temperature performance, low-temperature performance and viscosity-temperature performance of an asphalt pavement, capable of recycling a large number of waste resources, good in social benefit, low in energy consumption, low in environment-friendly treatment cost, low in raw material cost and suitable for popularization and application. The method also improves the diversified utilization of resources, effectively improves the ecological environment problem, and plays an important role in promoting the field of road construction and maintenance, guaranteeing the traffic safety, improving the public service quality and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering materials, and in particular to a multi-type fiber-carbide slag composite modified asphalt and a preparation method thereof. Background Art

[0002] my country has abundant crop straw resources, with an annual output of more than 700 million tons, but they have not been effectively utilized. Waste straw contains a lot of fiber, and waste straw has a wide source and low cost, so it is urgent to find effective ways to utilize it. In order to improve the diversified utilization of crop straw resources, using crop straw for road traffic fiber is one of the important ways.

[0003] On the other hand, asphalt pavement is widely used in my country and is an important foundation for the current national transportation construction. After in-depth research and scientific practice, it was found that under the combined influence of repeated loads imposed by vehicles and different environmental and climatic conditions, conventional asphalt concrete materials are prone to cracking, potholes and other damages. The decline in asphalt pavement performance is directly due to the above factors. As a result, these damages inevitably make it difficult for asphalt pavements to achieve the expected design service life, which in turn affects their overall performance. Therefore, it is particularly important to develop a new type of modified asphalt to extend the service life of asphalt pavements and solve high and low temperature diseases of pavements.

[0004] The information disclosed in this background technology section is only used to deepen the understanding of the background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0005] The present application provides a variety of fiber-carbide slag composite modified asphalt and a preparation method thereof, aiming to solve the technical problems that the service life of the existing asphalt pavement is less than expected due to insufficient road performance and frequent high and low temperature diseases.

[0006] According to one aspect of the present disclosure, a multi-type fiber-carbide slag composite modified asphalt is provided, which is made of the following raw materials in parts by weight: 100 parts of base asphalt, 1-2 parts of sweet potato vine straw fiber, 1-2 parts of bagasse fiber, and 2-3 parts of carbide slag.

[0007] In some embodiments of the present disclosure, the multi-type fiber-carbide slag composite modified asphalt is made of the following raw materials in parts by weight: 100 parts of base asphalt, 1.2 to 1.8 parts of sweet potato vine straw fiber, 1.2 to 1.8 parts of bagasse fiber, and 2.2 to 2.8 parts of carbide slag.

[0008] In some embodiments of the present disclosure, the multi-type fiber-carbide slag composite modified asphalt is made of the following raw materials: 100 parts of base asphalt, 1.4 parts of sweet potato vine straw fiber, 1.4 parts of bagasse fiber, and 2.4 parts of carbide slag.

[0009] In some embodiments of the present disclosure, the base asphalt is 70# and / or 90# base asphalt.

[0010] In some embodiments of the present disclosure, the length of the sweet potato vine straw fiber and bagasse fiber is 4 to 6 mm.

[0011] According to a second aspect of the present disclosure, a method for preparing a multi-type fiber-carbide slag composite modified asphalt is provided, comprising the following steps: (1) Prepare the raw materials according to the above raw material ratio; (2) Heating the base asphalt to 150-170°C to soften it; (3) washing the sweet potato vine straw and bagasse, cutting and drying them respectively, then soaking them in an alkaline solution at 55-65° C. and then rinsing them, and finally crushing, drying and sieving them to obtain sweet potato vine straw fibers and bagasse fibers; (4) The sweet potato vine straw fiber, bagasse fiber and carbide slag prepared in step (3) are sequentially added to the matrix asphalt, heated to 135-165° C., stirred at a constant temperature and low speed, and then subjected to high-speed shearing at the same temperature to obtain the product.

[0012] In some embodiments of the present disclosure, in step (3), the alkaline solution is a NaOH solution with a mass fraction of 2 to 3%.

[0013] In some embodiments of the present disclosure, in the step (4), stirring is first performed at a rate of 2000 to 4000 rpm for 20 to 40 min; and then shearing is performed at a rate of 1000 to 2000 rpm for 2 to 3 h.

[0014] One or more technical solutions provided in the embodiments of the present application have at least any of the following technical effects: 1. In the present application, when the sweet potato vine straw fiber, bagasse fiber and carbide slag are composite-modified asphalt, the synergistic effect of the three significantly enhances the mechanical properties of the asphalt mixture, improves the rutting resistance, cracking resistance, fatigue resistance and durability of the road surface, promotes the recycling of agricultural and industrial waste, and reduces environmental pollution. Among them, sweet potato vine straw fiber can form a network structure in asphalt, increase the cohesion and internal friction angle of asphalt mixture, thereby improving its shear strength and compressive strength. The addition of sweet potato vine straw fiber helps to improve the rutting resistance, cracking resistance and fatigue resistance of asphalt pavement, and extend the service life of the pavement; bagasse fiber can increase the adhesion and anti-stripping properties of asphalt mixture, reduce the erosion of asphalt mixture by water, and improve the durability of the pavement. The addition of bagasse fiber can also improve the workability of asphalt mixture, making it easier to spread and compact during construction. The dietary fiber and antioxidants rich in bagasse fiber may improve the antioxidant properties of asphalt to a certain extent and slow down asphalt aging; the mineral elements such as calcium and magnesium rich in carbide slag can react with acidic substances in asphalt to form stable compounds, thereby improving the stability of asphalt mixture. The addition of carbide slag helps to increase the density and water damage resistance of asphalt mixture, and improve the skid resistance and wear resistance of the pavement.

[0015] 2. The modified asphalt of the present application uses a composite material of sweet potato vine straw fiber, bagasse fiber, and carbide slag processed by a high-speed shear crusher as an asphalt modifier. On the one hand, the cellulose inside the widely available sweet potato vine straw fiber and bagasse fiber improves the rigidity of the composite material due to the molecular polarity and hydrogen bonding. On the other hand, under the high-temperature flow state of the matrix asphalt, the sweet potato vine straw fiber, bagasse fiber, and carbide slag can be quickly dispersed and adsorbed in the asphalt material, so that the load on the composite material can be dispersed and transferred, thereby improving the deformation resistance of the composite material, greatly improving the high-temperature rutting resistance and elasticity of the modified asphalt, and improving the low-temperature performance of the modified asphalt, which can effectively improve the bearing capacity and high and low temperature performance of asphalt pavement, and is suitable for use in heavy-load traffic roads and airport pavements.

[0016] 3. The composite modified asphalt prepared by the present application only needs to add sweet potato vine straw fiber, carbide slag, and bagasse fiber to the matrix asphalt in a molten state in sequence, and then heat and stir. For the modified asphalt processing enterprises, no equipment modification is required, and compared with the traditional SBS modified asphalt, the hot mix temperature is low and the amount of modifier added is small, which reduces the energy consumption in the production process and promotes energy conservation and emission reduction. The production process of composite modified asphalt is simple, the production cost is low, it is easy to industrialize, and it is economical and practical. At the same time, the present application can also recycle and utilize waste resources in large quantities, turning waste into treasure, with good social benefits, and low energy consumption, low environmental protection treatment fees, low raw material costs, and reduced environmental and resource pressures. The present application can effectively improve the recovery rate of waste resources and the level of high-value utilization, and open up new ways to develop green and low-carbon economic asphalt pavement materials. DETAILED DESCRIPTION

[0017] In order to better understand the technical solution of the present application, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0018] Unless otherwise specified, the raw materials and auxiliary raw materials involved in the following examples are all commercially available conventional raw materials; the preparation methods, detection methods and test methods involved are all conventional methods unless otherwise specified.

[0019] The composite modified asphalt in the following examples includes the following preparation steps: The raw materials are configured according to the raw material ratio of 100 parts of base asphalt, 1-2 parts of sweet potato vine straw fiber, 1-2 parts of bagasse fiber, and 2-3 parts of carbide slag.

[0020] (1) Heat 70# base asphalt (A-grade 70# road petroleum asphalt from Zhengzhou Municipal Engineering Corporation) in an electric heated air drying oven at 160°C until it melts and flows.

[0021] (2) The sweet potato vine straw and bagasse in their natural state were cleaned to remove dust and other water-soluble impurities on their surfaces, and the surfaces were wiped dry and cut into small pieces of about 10 mm in length and then dried to prepare a 3% NaOH solution required for the experiment. The small pieces of sweet potato vine straw and bagasse were placed in a 3% NaOH solution at 60°C for treatment, and then washed to neutrality. Finally, they were crushed, dried and sieved to obtain sweet potato vine straw fibers and bagasse fibers.

[0022] (3) The sweet potato vine straw fiber, bagasse fiber and carbide slag prepared in step (2) are sequentially added to the molten 70# matrix asphalt in step (1), and after heating to 150°C, constant temperature and low-speed stirring is started at a speed of 2500 rpm for 30 min, and then high-speed shearing is performed at the same temperature at a speed of 1500 rpm for 2 h to obtain a composite modified asphalt.

[0023] Example 1: A multi-type fiber-carbide slag composite modified asphalt mixture is made from the following raw materials in parts by weight: 100 parts of 70# matrix asphalt, 1 part by weight of sweet potato vine straw fiber, 2 parts by weight of carbide slag, 1 part by weight of bagasse fiber, and the length of the fiber is 4 mm.

[0024] Example 2: A multi-type fiber-carbide slag composite modified asphalt, made from the following raw materials in parts by weight: 100 parts of 70# matrix asphalt, 1.2 parts by weight of sweet potato vine straw fiber, 2.2 parts by weight of carbide slag, 1.2 parts by weight of bagasse fiber, and the length of the fiber is 5 mm.

[0025] Example 3: A multi-type fiber-carbide slag composite modified asphalt, made from the following raw materials in parts by weight: 100 parts of 70# matrix asphalt, 1.4 parts by weight of sweet potato vine straw fiber, 2.4 parts by weight of carbide slag, 1.4 parts by weight of bagasse fiber, and the length of the fiber is 4 mm.

[0026] Example 4: A multi-type fiber-carbide slag composite modified asphalt, made from the following raw materials in parts by weight: 100 parts of 70# matrix asphalt, 1.6 parts by weight of sweet potato vine straw fiber, 2.6 parts by weight of carbide slag, 1.6 parts by weight of bagasse fiber, and the length of the fiber is 6 mm.

[0027] Example 5: A multi-type fiber-carbide slag composite modified asphalt, made from the following raw materials in parts by weight: 100 parts of 70# matrix asphalt, 1.8 parts by weight of sweet potato vine straw fiber, 2.8 parts by weight of carbide slag, 1.8 parts by weight of bagasse fiber, and the fiber length is 4.5 mm.

[0028] Example 6: A multi-type fiber-carbide slag composite modified asphalt, made from the following raw materials in parts by weight: 100 parts of 70# matrix asphalt, 2 parts by weight of sweet potato vine straw fiber, 3 parts by weight of carbide slag, 2 parts by weight of bagasse fiber, and the length of the fiber is 5 mm.

[0029] The composite modified asphalt in Examples 1-6 was subjected to a road performance test, and the road performance test items included a needle penetration test, a softening point test, an asphalt ductility test, and a Brookfield rotational viscosity test, which were used to test the performance of the composite modified asphalt mixture of the present invention, and were compared and analyzed with ordinary 70# base asphalt without adding modifying materials. The test results are shown in Table 1.

[0030] Table 1 Comparison of main performance indicators of various composite modified asphalt mixtures .

[0031] As can be seen from Table 1, the needle penetration of the composite modified asphalt is much smaller than that of ordinary asphalt (70# base asphalt), indicating that the composite modified asphalt has stronger consistency and hardness than ordinary asphalt; the softening point of the composite modified asphalt is much larger than that of ordinary asphalt, indicating that the composite modified asphalt has stronger high temperature stability and deformation resistance; the ductility of the composite modified asphalt is greater than that of ordinary asphalt, indicating that the low temperature stability of the composite modified asphalt is stronger than that of ordinary asphalt; the Brookfield rotation viscosity of the composite modified asphalt is greater than that of ordinary asphalt, indicating that the composite modified asphalt has higher viscosity-temperature performance.

[0032] The composite modified asphalt of this application meets the relevant requirements of the Ministry of Transport's standard JTG F40-2004 "Technical Specifications for Highway Asphalt Pavement Construction". Its high temperature performance, low temperature performance, viscosity-temperature performance and other indicators are significantly higher than those of ordinary asphalt, indicating that the composite modified asphalt of this application has superior performance.

[0033] The present application has been described in detail above in conjunction with the embodiments; however, those skilled in the art will appreciate that, without departing from the spirit and scope of the present invention, the specific parameters in the above embodiments may be changed, or the relevant materials and method steps may be replaced by equivalents, thereby forming multiple specific embodiments, which are all within the common variation range of the present application and will not be described in detail one by one here.

Claims

1. A multi-type fiber-carbide slag composite modified asphalt, characterized in that: The invention is prepared from the following raw materials in parts by weight: 100 parts of base asphalt, 1-2 parts of sweet potato vine straw fiber, 1-2 parts of bagasse fiber and 2-3 parts of carbide slag.

2. The multi-type fiber-carbide slag composite modified asphalt according to claim 1, characterized in that: The invention is prepared from the following raw materials: 100 parts of base asphalt, 1.2-1.8 parts of sweet potato vine straw fibers, 1.2-1.8 parts of bagasse fibers and 2.2-2.8 parts of carbide slag.

3. The multi-type fiber-carbide slag composite modified asphalt according to claim 1, characterized in that: The invention is made from the following raw materials: 100 parts of base asphalt, 1.4 parts of sweet potato vine straw fiber, 1.4 parts of bagasse fiber and 2.4 parts of carbide slag.

4. The multi-type fiber-carbide slag composite modified asphalt according to claim 1, characterized in that: The matrix asphalt is 70# and / or 90# matrix asphalt.

5. The multi-type fiber-carbide slag composite modified asphalt according to claim 1, characterized in that: The length of the sweet potato vine straw fiber and bagasse fiber is 4-6 mm.

6. A method for preparing the multi-type fiber-carbide slag composite modified asphalt according to claim 1, characterized in that: The steps include: (1) preparing the raw materials according to the raw material ratio described in claim 1; (2) Heating the base asphalt to 150-170°C to soften it; (3) washing the sweet potato vine straw and bagasse, cutting and drying them respectively, soaking them in an alkaline solution at 55-65° C., rinsing them, and finally crushing, drying and sieving them to obtain sweet potato vine straw fibers and bagasse fibers respectively; (4) The sweet potato vine straw fiber, bagasse fiber and carbide slag prepared in step (3) are sequentially added to the matrix asphalt, heated to 135-165° C., stirred at a constant temperature and low speed, and then subjected to high-speed shearing at the same temperature to obtain the product.

7. The preparation method according to claim 5, characterized in that: In the step (3), the alkaline solution is a NaOH solution with a mass fraction of 2 to 3%.

8. The preparation method according to claim 5, characterized in that: In the step (4), the mixture is first stirred at a rate of 2000 to 4000 rpm for 20 to 40 minutes, and then sheared at a rate of 1000 to 2000 rpm for 2 to 3 hours.