A rapid construction method for steel slag asphalt pavement

Abstract

This invention discloses a rapid construction method for steel slag asphalt pavement. The construction method involves layering steel slag aggregate in a gradation manner to create a skeleton-interlocking structure in the aggregate. This method utilizes the steel slag aggregate to provide excellent road performance for the asphalt pavement while simultaneously enabling rapid construction of the asphalt pavement. This method meets the construction and quality requirements of non-heavy-load asphalt pavement for emergency needs.

Description

Technical Field

[0001] This invention relates to the field of asphalt pavement construction, and more particularly to a rapid construction method for steel slag asphalt pavement. Background Technology

[0002] China's steel industry is enormous, producing over 160 million tons of steel slag annually, with accumulated stockpiles exceeding 1.2 billion tons. Utilizing steel slag to prepare high-grade asphalt pavement aggregates is the most promising technology for recycling this massive amount of steel slag. Steel slag asphalt concrete is already being promoted and applied in my country. The water damage resistance and rutting resistance of asphalt concrete prepared using steel slag meet the requirements of the Ministry of Transport's "Technical Specifications for Asphalt Pavement Construction".

[0003] Traditional hot-mix asphalt pavement construction involves numerous steps, including aggregate storage, aggregate heating, asphalt mixture mixing, material placement, vehicle transportation, and on-site paving and compaction. Furthermore, hot-mix asphalt pavement construction necessitates an asphalt mixing plant, resulting in substantial investment and high energy consumption. However, for non-heavy-load asphalt pavements with emergency needs, traditional methods are no longer sufficient. Emergency asphalt pavements require minimal paving time, minimal construction machinery, and asphalt pavement quality capable of supporting vehicles with a 20-ton load.

[0004] Currently, relevant patent documents have disclosed asphalt pavement construction methods. For example, Chinese patent document CN112853876B discloses a method to solve the problems of road marking recognition and improve the roller compaction quality of curved road surfaces; Chinese patent document CN113772997B discloses an asphalt mixture containing graphite powder and styrene-butadiene latex to solve the problem of decreased water stability after adding too much graphite powder to conductive asphalt concrete; and Chinese patent document CN114108413A proposes a method to improve the smoothness of road surface construction. However, all of the above asphalt pavement construction methods are based on the construction methods specified in the current Ministry of Transport standard JTG F40-2004.

[0005] Therefore, it is necessary to propose a rapid construction method for steel slag asphalt pavement to meet the construction and quality requirements of non-heavy-load asphalt pavement for emergency needs. Summary of the Invention

[0006] This invention provides a rapid construction method for steel slag asphalt pavement, which meets the construction and quality requirements of non-heavy-load asphalt pavement for emergency needs.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] A rapid construction method for steel slag asphalt pavement includes the following steps: spreading asphalt onto the pavement to be paved, then spreading steel slag aggregate on the asphalt layer, and then compacting the pavement to complete the pavement laying; the steel slag aggregate has a particle size range of less than 16mm and is evenly spread on the asphalt layer in descending order of particle size.

[0009] Furthermore, the steel slag aggregate has three particle size ranges: 13.2mm-9.5mm, 9.5-4.75mm and less than 4.75mm, which are evenly sprinkled on the asphalt layer in order of decreasing particle size.

[0010] Preferably, the steel slag aggregate is provided in the following proportions by weight: 30-40 parts for particles with a diameter range of 13.2mm-9.5mm, 20-30 parts for particles with a diameter range of 9.5-4.75mm, and 30-50 parts for particles with a diameter range of less than 4.75mm.

[0011] Furthermore, the amount of steel slag aggregate spread is 3.0-4.3 kg per square meter.

[0012] Furthermore, the asphalt includes at least one of SBS modified asphalt, SBR modified asphalt, lake asphalt modified asphalt, rock asphalt modified asphalt, and road petroleum asphalt.

[0013] Furthermore, the amount of asphalt applied is 1.2-1.6 kg per square meter.

[0014] Furthermore, the steel slag aggregate is spread using a synchronous crushed stone seal vehicle.

[0015] Furthermore, the compaction process is as follows: monitor the temperature of the asphalt pavement to be paved, and start compaction when it drops to 120-140℃, with 3-5 passes of static compaction; stop compaction when the temperature of the asphalt pavement drops to 100℃.

[0016] Furthermore, the construction method also includes the steps of cleaning the road before the asphalt spraying step and setting up barriers on both sides of the road surface to be paved.

[0017] Furthermore, the construction method also includes an acceptance step after the road surface is paved, and the acceptance indicators include the permeability coefficient, compaction degree and Marshall stability of the core sample.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The construction method provided by this invention uses steel slag aggregate in a particle size classification manner, so that the sprayed steel slag aggregate has a skeleton interlocking structure. On the one hand, it makes full use of steel slag aggregate to provide good road performance for asphalt pavement, and on the other hand, it realizes rapid construction of asphalt pavement, meeting the construction and quality requirements of non-heavy-load asphalt pavement for emergency needs. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] The hot-quenched steel slag produced by metallurgical plants has a particle size between 0-16mm. Calculated by specific gravity, the natural particle size range is 0-3mm (25%), 3-5mm (30%), 5-10mm (30%), and 10-16mm (15%). Considering the huge stockpile of steel slag and its application prospects, rapid construction of steel slag asphalt pavement can be achieved.

[0022] Based on this, an embodiment of the present invention provides a rapid construction method for steel slag asphalt pavement, the specific steps of which include:

[0023] (1) Construction preparation;

[0024] (2) Asphalt spraying;

[0025] (3) Distribution of steel slag aggregate;

[0026] (4) Road surface compaction;

[0027] (5) Project acceptance.

[0028] The specific construction process for each step is as follows:

[0029] (1) The construction preparation process is as follows: first, the road is swept, and then baffles are set on both sides of the road to be paved. The baffles should be set at 90° perpendicular to the ground plane.

[0030] (2) The asphalt used in the asphalt spraying process includes one or more of SBS modified asphalt, SBR modified asphalt, lake asphalt modified asphalt, rock asphalt modified asphalt, and road petroleum asphalt. The asphalt is heated to the melting temperature by a synchronous chip seal vehicle and then sprayed from the nozzle onto the road surface to be paved. The spraying amount is 1.2-1.6 kg per square meter.

[0031] (3) The steel slag aggregate used in the steel slag aggregate distribution process should be steel slag tailings produced by the hot quenching process of a metallurgical plant. The preferred particle size is divided into three categories: 13.2mm-9.5mm, 9.5-4.75mm, and less than 4.75mm. The three particle sizes of steel slag aggregate are spread on the road surface to be paved in three stages according to the order of particle size from large to small using a synchronous chip seal vehicle, forming a skeleton interlocking structure, which improves the pavement properties including permeability coefficient (mL / min), compaction degree (%), and Marshall stability of core samples (kN).

[0032] (4) Monitor the temperature of the asphalt pavement to be laid. When it drops to 120-140℃, start rolling. Use a steel wheel roller to perform static rolling 3-5 times. Stop rolling when the temperature of the asphalt pavement drops to 100℃. At this time, the asphalt pavement has been laid.

[0033] (5) After the asphalt pavement is laid, excess aggregate is cleaned up by manual or mechanical means and recycled. The baffles are removed and construction technicians are arranged to carry out project acceptance. The test indicators include permeability coefficient (mL / min), compaction degree (%) and Marshall stability of core sample (kN), which are not greater than 120 mL / min, not less than 98% and 8kN, respectively.

[0034] In a preferred embodiment, the percentages of the three aggregates are: 30-40 parts for 13.2mm-9.5mm, 20-30 parts for 9.5-4.75mm, and 30-50 parts for less than 4.75mm. The total application rate of the three aggregate grades is 3.0-4.3 kg per square meter. By using steel slag aggregate in a gradation manner, the applied steel slag aggregate has a better skeleton interlocking structure. On the one hand, it fully utilizes the steel slag aggregate to provide good road performance for asphalt pavement; on the other hand, it enables rapid construction of asphalt pavement, meeting the construction and quality requirements of non-heavy-load asphalt pavement for emergency needs.

[0035] In the above embodiments, due to the good adhesion between steel slag aggregate and asphalt, the construction process of asphalt pavement is greatly simplified and the requirements for construction machinery are reduced by setting the asphalt and aggregate spraying amounts and controlling the construction temperature. Traditional asphalt pavement construction requires the use of pavers to spray the mixture, and construction can only be carried out sequentially. If different project locations are encountered, a lot of time needs to be spent moving the paver. Moreover, hot-mix asphalt mixtures are all produced in asphalt mixing plants, and vehicles are needed to transport the asphalt mixture to the site, wasting a lot of time. In contrast, this patent uses synchronous chip seal vehicles to pave asphalt pavement, which has better mobility and a very fast paving speed, meeting the requirements for rapid construction and emergency response.

[0036] In the above embodiments, steps (1) and (5) are steps commonly used by those skilled in the art for road construction standards. They are only used as a reference for standardized construction and are not intended to limit the completion of emergency construction. Example 1

[0037] The construction preparation process is as follows: first, the road is swept, and then baffles are set on both sides of the road surface to be paved. The baffles should be set at a 90° angle perpendicular to the ground plane.

[0038] SBS modified asphalt was selected. The asphalt was heated to its melting temperature of 165°C using a synchronous chip seal vehicle and then sprayed onto the road surface to be paved from the nozzle at a rate of 1.6 kg per square meter.

[0039] The steel slag aggregate should be steel slag tailings produced using a hot-pressing process, and its particle size should be divided into three categories: 13.2mm-9.5mm, 9.5-4.75mm, and less than 4.75mm. Using a synchronous chip sealer, the three types of steel slag aggregate are applied to the pavement in three stages, in descending order of particle size. The weight ratio of the three aggregates is: 30 parts for 13.2mm-9.5mm, 30 parts for 9.5-4.75mm, and 40 parts for less than 4.75mm. The total application rate of the three aggregates is 3.0 kg per square meter.

[0040] Monitor the temperature of the asphalt pavement to be laid. When it drops to 140℃, begin compaction using a steel wheel roller, first applying five passes of static compaction. Stop compaction when the asphalt pavement temperature drops to 100℃, at which point the asphalt pavement is complete.

[0041] After the asphalt pavement is laid, excess aggregate is cleaned up manually or mechanically for recycling, the retaining walls are removed, and construction technicians are arranged to carry out project acceptance. Example 2

[0042] In this embodiment, the construction preparation and project acceptance steps are the same as in Embodiment 1.

[0043] SBR modified asphalt was selected. The asphalt was heated to a melting temperature of 160 degrees Celsius using a synchronous chip seal vehicle and then sprayed onto the road surface to be paved from the nozzle at a rate of 1.3 kg per square meter.

[0044] The steel slag aggregate should be tailings produced using a hot-pressing process, and its particle size should be divided into three categories: 13.2mm-9.5mm, 9.5-4.75mm, and less than 4.75mm. Using a synchronized chip sealer, the three types of steel slag aggregate are applied to the pavement in three stages, in descending order of particle size. The weight ratio of the three aggregates is: 35 parts for 13.2mm-9.5mm, 22 parts for 9.5-4.75mm, and 43 parts for less than 4.75mm. The total application rate of the three aggregates is 4.0 kg per square meter.

[0045] Monitor the temperature of the asphalt pavement to be laid. When it drops to 130℃, begin compaction using a steel wheel roller, first applying five passes of static compaction. Stop compaction when the asphalt pavement temperature drops to 100℃, at which point the asphalt pavement is complete. Example 3

[0046] In this embodiment, the construction preparation and project acceptance steps are the same as in Embodiment 1.

[0047] The asphalt used is lake asphalt modified asphalt. The asphalt is heated to a melting temperature of 170 degrees Celsius using a synchronous chip seal vehicle and then sprayed onto the road surface to be paved from the nozzle at a rate of 1.2 kg per square meter.

[0048] The steel slag aggregate should be steel slag tailings produced using a hot-pressing process, and its particle size should be divided into three categories: 13.2mm-9.5mm, 9.5-4.75mm, and less than 4.75mm. Using a synchronized chip sealer, the three types of steel slag aggregate are applied to the pavement in three stages, in descending order of particle size. The weight ratio of the three aggregates is: 38 parts for 13.2mm-9.5mm, 27 parts for 9.5-4.75mm, and 35 parts for less than 4.75mm. The total application rate of the three aggregate grades is 3.0 kg per square meter.

[0049] Monitor the temperature of the asphalt pavement to be laid. When it drops to 127°C, begin compaction using a steel wheel roller for four static passes. Stop compaction when the asphalt pavement temperature drops to 100°C; at this point, the asphalt pavement is complete. Example 4

[0050] In this embodiment, the construction preparation and project acceptance steps are the same as in Embodiment 1.

[0051] The asphalt used is modified rock asphalt. The asphalt is heated to a melting temperature of 170 degrees Celsius using a synchronous chip seal vehicle and then sprayed onto the road surface to be paved from the nozzle at a rate of 1.2 kg per square meter.

[0052] The steel slag aggregate should be tailings produced using a hot-pressing process, and its particle size should be divided into three categories: 13.2mm-9.5mm, 9.5-4.75mm, and less than 4.75mm. Using a synchronized chip sealer, the three types of steel slag aggregate are applied to the pavement in three stages, in descending order of particle size. The weight ratio of the three aggregates is: 39 parts for 13.2mm-9.5mm, 28 parts for 9.5-4.75mm, and 33 parts for less than 4.75mm. The total application rate of the three aggregates is 3.0 kg per square meter.

[0053] Monitor the temperature of the asphalt pavement to be laid. When it drops to 130℃, begin compaction using a steel wheel roller, first applying it statically three times. Stop compaction when the asphalt pavement temperature drops to 100℃; at this point, the asphalt pavement is complete. Example 5

[0054] In this embodiment, the construction preparation and project acceptance steps are the same as in Embodiment 1.

[0055] The asphalt used is road petroleum asphalt. The asphalt is heated to a melting temperature of 150 degrees Celsius using a synchronous chip sealer and then sprayed onto the road surface to be paved from the nozzle at a rate of 1.6 kg per square meter.

[0056] The steel slag aggregate should be steel slag tailings produced using a hot-pressing process, and its particle size should be divided into three categories: 13.2mm-9.5mm, 9.5-4.75mm, and less than 4.75mm. Using a synchronous chip sealer, the three types of steel slag aggregate are applied to the pavement in three stages, in descending order of particle size. The weight ratio of the three aggregates is: 39 parts for 13.2mm-9.5mm, 28 parts for 9.5-4.75mm, and 33 parts for less than 4.75mm. The total application rate of the three aggregate grades is 3.4kg per square meter.

[0057] Monitor the temperature of the asphalt pavement to be laid. When it drops to 120°C, begin compaction using a steel wheel roller, initially applying five passes of static compaction. Stop compaction when the asphalt pavement temperature drops to 100°C; at this point, the asphalt pavement is complete.

[0058] Comparative Example 1

[0059] The steel slag aggregate used has two particle sizes: 9.5-4.75mm and smaller than 4.75mm. The weight ratio is 30 parts for 9.5-4.75mm and 40 parts for smaller than 4.75mm. The total application rate of the two aggregate sizes is 3.0kg per square meter. Other steps are the same as in Example 1.

[0060] Comparative Example 2

[0061] The steel slag aggregate used has two particle sizes: 13.2mm-9.5mm and less than 4.75mm. The weight ratio is 30 parts for 13.2mm-9.5mm and 40 parts for less than 4.75mm. The total application rate of the two aggregate sizes is 3.0kg per square meter. Other steps are the same as in Example 1.

[0062] Comparative Example 3

[0063] The steel slag aggregate used has two particle sizes: 13.2mm-9.5mm and 9.5mm-4.75mm. The weight ratio is 30 parts for 13.2mm-9.5mm and 30 parts for 9.5mm-4.75mm. The total application rate of the two aggregate sizes is 3.0kg per square meter. Other steps are the same as in Example 1.

[0064] Construction was carried out on the experimental roadbed according to the construction methods of the above embodiments and comparative examples. During the acceptance process, construction technicians conducted project acceptance, and the test indicators included permeability coefficient (mL / min), compaction degree (%), and Marshall stability of core samples (kN). The results are shown in Table 1.

[0065] Table 1: Asphalt pavement test data for each embodiment

[0066] performance Permeability coefficient (mL / min) Compaction degree (%) Marshall stability of core sample (kN) Example 1 60 98.5 15.3 Example 2 75 99 16.3 Example 3 72 99.4 12.4 Example 4 95 99.2 12.3 Example 5 110 99.1 13.9 Comparative Example 1 210 89.3 8.3 Comparative Example 2 309 83.2 7.8 Comparative Example 3 440 80.3 8.1

[0067] The experimental examples, based on the current Chinese standard "Technical Specification for Construction of Asphalt Pavement of Highways" JTG F 40-2004, conducted performance tests on steel slag asphalt pavements using different embodiments. The results showed that the permeability coefficient, compaction degree, and Marshall stability of the different schemes provided in Examples 1-5 all met the requirements of JTG F40-2004. Therefore, it can be concluded that the above-mentioned steel slag asphalt pavements can all be paved using rapid construction methods.

[0068] The steel slag aggregates used in Comparative Examples 1-3 each had one less particle size range than those in Example 1. Their permeability coefficient, compaction degree, and Marshall stability all decreased to varying degrees compared to Example 1. In particular, the permeability coefficients all exceeded 120 mL / min, resulting in significant water seepage on the road surface and making it unsuitable for traffic. This demonstrates the coordination of performance assurance when using steel slag aggregates with three different particle size distributions.

[0069] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for rapid construction of a steel slag asphalt pavement, characterized by, Includes the following steps: Asphalt is sprayed onto the road surface to be paved, then steel slag aggregate is sprayed onto the asphalt layer, and then the road surface is compacted to complete the road paving; the particle size range of the steel slag aggregate is less than 16mm, and it is evenly sprayed onto the asphalt layer in order of decreasing particle size. The steel slag aggregate, by weight, comprises the following components: 30-40 parts for particles with a diameter range of 13.2mm-9.5mm, 20-30 parts for particles with a diameter range of 9.5-4.75mm, and 30-50 parts for particles with a diameter range of less than 4.75mm. The steel slag aggregate is derived from the tailings of the hot quenching process, and the spreading amount is 3.0-4.3 kg per square meter; The amount of asphalt applied is 1.2-1.6 kg per square meter.

2. The construction method according to claim 1, characterized in that, The asphalt includes at least one of SBS modified asphalt, SBR modified asphalt, lake asphalt modified asphalt, rock asphalt modified asphalt, and road petroleum asphalt.

3. The construction method according to claim 1, characterized in that, The steel slag aggregate is spread using a synchronous crushed stone seal vehicle.

4. The construction method according to claim 1, characterized in that, The compaction process is as follows: monitor the temperature of the asphalt pavement to be paved, and start compaction when it drops to 120-140℃, with 3-5 passes of static compaction; stop compaction when the temperature of the asphalt pavement drops to 100℃.

5. The method of claim 1, wherein, It also includes the steps of cleaning the road before the asphalt is sprayed and setting up barriers on both sides of the road surface to be paved.

6. The method of claim 1, wherein, It also includes the step of acceptance after the road surface is laid, and the acceptance indicators include the permeability coefficient, compaction degree and Marshall stability of the core sample.