Pouring type semi-flexible concrete based on water reaction type cold-mixed asphalt mixture and preparation method of pouring type semi-flexible concrete

Abstract

The invention discloses pouring type semi-flexible concrete based on a water reaction type cold-mixed asphalt mixture. The pouring type semi-flexible concrete is prepared from the following raw materials in parts by weight: 3-4 parts of water reaction type cold-mixed asphalt, 100 parts of mineral aggregate, 10-12 parts of a cement grouting material and 4-5 parts of water, the preparation method comprises the following steps: 1, preparing the water-reactive cold-mixed asphalt; 2, preparing a water reaction type cold-mix asphalt mixture; 3, preparing a rut plate test piece of the water reaction type cold-mixed asphalt mixture; 4, preparing a cement grouting material; 5, pouring a cement grouting material into the surface of the sealed rut plate test piece; and sixthly, normal-temperature maintenance is conducted after cleaning. By utilizing the characteristics of complete cold mixing and cold paving, easiness in compaction, high strength forming speed and simplicity and convenience in construction of the water reaction type cold-mixed asphalt mixture, the construction of the pouring type semi-flexible concrete pavement is quicker and more convenient, the pavement performance is excellent, the repair efficiency of asphalt pavement ruts and other diseases is improved, and the service life of the pavement is prolonged. The method can be widely applied to asphalt pavement rut repair and other maintenance projects.

Description

Technical Field

[0001] The invention belongs to the technical field of asphalt pavement engineering, and in particular relates to a pourable semi-flexible concrete based on a water-reactive cold-mix asphalt mixture and a preparation method thereof. Background Art

[0002] The poured semi-flexible pavement refers to the pavement formed by pouring special cement mortar into the base asphalt mixture with large void ratio (20% to 28%). It has both the rigidity of cement concrete pavement and the flexibility of asphalt concrete pavement. The semi-flexible pavement material forms material strength together with cement stone through the mutual interlocking effect between aggregates, which improves the ability of the pavement to resist load. Therefore, its high temperature stability (anti-deformation, anti-shear performance) and water damage resistance are much better than ordinary asphalt concrete pavement, and its fatigue resistance and anti-skid wear resistance are not inferior to ordinary asphalt concrete pavement. At the same time, it has the characteristics of cement concrete pavement such as oil resistance, acid resistance and easy coloring. In addition, the semi-flexible pavement does not require special construction machinery for paving the large void base asphalt mixture, and only ordinary grouting machinery is needed for the pouring of cement mortar, so it is easy to construct and low in cost. Based on the above characteristics, semi-flexible pavement has become an important treatment measure for improving the sections with prominent rutting problems such as level crossings, bus stations, and BRT lanes in China in recent years.

[0003] However, currently, the large-void base asphalt mixture of semi-flexible pavement is almost entirely paved with hot-mix asphalt mixture. During the production process of hot-mix asphalt mixture, aggregates and asphalt need to be heated, so mixing plants must be relied upon. However, for most application scenarios of semi-flexible pavement (such as level crossings, bus stations, etc.), the amount of base asphalt mixture required is very small, making it difficult to build a mixing plant on site for production. Therefore, commercial mixing plants have to be found, which often leads to long transportation distances. Not only is it difficult to guarantee the production quality, but the paving and compaction temperature when transported to the site is also difficult to guarantee, which ultimately affects the quality of pavement maintenance and repair. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture in view of the shortcomings of the above-mentioned prior art. The poured semi-flexible concrete makes use of the characteristics of the water-reactive cold-mix asphalt mixture, which is completely cold-mixed and cold-laid, easy to compact, fast in strength formation, and simple in construction, so that the construction of the poured semi-flexible concrete pavement is faster and more convenient, and the road performance is excellent, which greatly improves the repair efficiency of asphalt pavement rutting and other diseases, and effectively solves the problem that the traditional hot-mix base asphalt mixture needs to rely on the asphalt mixing station and cannot be constructed in rainy weather or low temperature seasons.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture, characterized in that it is made of raw materials including the following parts by weight: 3 to 4 parts of water-reactive cold-mix asphalt, 100 parts of mineral material, 10 to 12 parts of cement grouting material, and 4 to 5 parts of water; by weight, 1 to 2 parts of reaction medium water are sprayed on the water-reactive cold-mix asphalt mixture composed of water-reactive cold-mix asphalt and mineral material when it is formed.

[0006] The above-mentioned pourable semi-flexible concrete based on water-reactive cold-mix asphalt mixture is characterized in that the water-reactive cold-mix asphalt is made of the following raw materials in parts by weight: 0.5 parts of dimethylformamide, 0.3 parts of tung oil, 3 parts of base asphalt, and 0.02 parts of curing agent. Usually, the curing agent is calcium hydroxide.

[0007] The above-mentioned poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture is characterized in that the mineral material is composed of the following raw materials in parts by weight: 19 parts of coarse aggregate of 10mm to 20mm, 74 parts of coarse aggregate of 5mm to 10mm, 5 parts of fine aggregate of 0 to 3mm, and 2 parts of mineral powder.

[0008] The above-mentioned poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture is characterized in that, by weight, 2 parts of reaction medium water are sprayed when the water-reactive cold-mix asphalt mixture is used to form a rutting plate specimen.

[0009] The above-mentioned poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture is characterized in that the cement grouting material is made of the following raw materials in parts by weight: 3-4 parts of Portland cement, 3-4 parts of sulphoaluminate cement, 0.2-0.5 parts of fly ash, 2-3 parts of quartz sand, 0.002-0.003 parts of water reducing agent, and 4-5 parts of water. More preferably, the cement grouting material is made of the following raw materials in parts by weight: 4 parts of Portland cement, 4 parts of sulphoaluminate cement, 0.2 parts of fly ash, 2 parts of quartz sand, 0.002 parts of water reducing agent, and 4 parts of water.

[0010] The above-mentioned poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture is characterized in that the gradation of the water-reactive cold-mix asphalt mixture is SPAC-16, and the void ratio is 20% to 28%.

[0011] The above-mentioned poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture is characterized in that the particle size of the quartz sand is 100-200 meshes.

[0012] The above-mentioned poured semi-flexible concrete based on water-reactive cold mix asphalt mixture is characterized in that the water reducer is a polycarboxylic acid high-performance water reducer.

[0013] At the same time, the present invention also discloses a method for preparing the poured semi-flexible concrete based on the water-reactive cold mix asphalt mixture as described above, characterized in that the method comprises the following steps:

[0014] Step 1: Heat the base asphalt to 140°C to 150°C, add dimethylformamide, tung oil and curing agent into the base asphalt and stir evenly to prepare water-reactive cold mix asphalt;

[0015] Step 2: The water-reactive cold-mix asphalt prepared in step 1 is mixed evenly with mineral materials manually or by a mixing machine to prepare a water-reactive cold-mix asphalt mixture;

[0016] Step 3: Place the water-reactive cold-mix asphalt mixture prepared in step 2 into a rutting plate test mold, spray water on the surface, and then roll and shape it, and cure it at room temperature for 12 hours to obtain a rutting plate specimen with a void ratio of 20% to 28%;

[0017] Step 4: Mix the silicate cement, sulphoaluminate cement, fly ash and quartz sand evenly, then add the mixed solution of water reducer and water, and stir at a speed of not less than 1200 r / min for not less than 2 min to obtain cement grouting material;

[0018] Step 5: Use plasticine or plastic tape to seal the gaps around the rutting plate specimen prepared in step 3, and then pour the cement grouting material obtained in step 4 onto the sealed surface of the rutting plate specimen, so that the cement grouting material flows into the skeleton gap of the rutting plate specimen under the action of its own weight until it is completely impermeable;

[0019] Step 6. Use a scraper or brush to clean the excess cement grouting material on the surface of the rutting plate specimen in step 5 until 10mm to 20mm of coarse aggregate is exposed on the surface, and then cure at room temperature for not less than 12 hours.

[0020] Usually, the present invention first adds the coarse aggregate and fine aggregate in the mineral material into a mixing pot and dry mixes for not less than 30 seconds, then adds water-reactive cold mix asphalt and stirs for not less than 60 seconds, and then adds the mineral powder in the mineral material and stirs for not less than 60 seconds.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The poured semi-flexible concrete of the present invention adopts water-reactive cold-mix asphalt mixture instead of traditional hot-mix base asphalt mixture, and utilizes the characteristics of water-reactive cold-mix asphalt mixture that is completely cold-mixed and cold-laid, easy to compact, fast in strength formation, and simple in construction, so that the construction of poured semi-flexible concrete pavement is faster and more convenient, greatly improving the efficiency of repairing asphalt pavement defects such as rutting, and effectively solving the problem that traditional hot-mix base asphalt mixture needs to rely on asphalt mixing plants and cannot be constructed in rainy weather or low temperature seasons. In addition, various performance indicators are not lower than those of traditional poured semi-flexible concrete based on hot-mix asphalt mixture, and the performance is stable and economical, so it can be widely used in maintenance projects such as asphalt pavement rutting repair.

[0023] 2. The water-reactive cold-mix asphalt in the water-reactive cold-mix asphalt mixture of the present invention has good fluidity at room temperature. The mixed mixture has high looseness and good fluidity in a water-free state, has excellent construction and workability, can coexist with the water-reactive curing agent for a long time when sealed and stored, and has good stability. When used, after the pavement is paved, the surface is sprinkled with water to moisten it and rolled in time, so that the curing agent can be activated to quickly undergo a water-activated reaction inside the mixture to form strength. The initial strength can be quickly formed in about 30 minutes, and the surface reaches a preliminary hardening state. The strength can be basically formed in 2 hours, and the Marshall stability can reach more than 6kN in 24 hours. In addition, various technical indicators can basically reach the technical level of hot-mix asphalt mixtures, overcoming the shortcomings of traditional cold-mix asphalt mixtures such as slow strength growth and fear of water erosion. The construction is simple, which is conducive to the large-scale production and promotion and application of poured semi-flexible concrete.

[0024] 3. The poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture prepared by the present invention fully complies with the standard of China Association for Engineering Construction Standardization "Technical Specification for Road Pouring Semi-flexible Pavement" (T / CECS G D51-01-2019) and the standard of China Highway and Transportation Society "Technical Guide for Design and Construction of Grouting Composite Pavement" (T / CHTS10102-2023), and the construction process is green and environmentally friendly, efficient and convenient, and has excellent road performance, and has broad promotion prospects and application value.

[0025] The technical solution of the present invention is further described in detail below through embodiments. DETAILED DESCRIPTION

[0026] Example 1

[0027] The poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture of this embodiment is made of the following raw materials in parts by weight: 3.5 parts of water-reactive cold-mix asphalt, 100 parts of mineral material, 10 parts of cement grouting material, and 4 parts of water; by weight, 1 part of reaction medium water is sprayed when the water-reactive cold-mix asphalt mixture composed of water-reactive cold-mix asphalt and mineral material is formed;

[0028] The water-reactive cold mix asphalt is made of the following raw materials in parts by weight: 0.5 parts of dimethylformamide, 0.3 parts of tung oil, 3 parts of No. 70 base asphalt, and 0.02 parts of curing agent calcium hydroxide;

[0029] The mineral material is composed of the following raw materials in parts by weight: 19 parts of coarse aggregate of 10mm to 20mm, 74 parts of coarse aggregate of 5mm to 10mm, 5 parts of fine aggregate of 0 to 3mm, and 2 parts of mineral powder;

[0030] The cement grouting material is made of the following raw materials in parts by weight: 4 parts of silicate cement, 4 parts of sulphoaluminate cement, 0.2 parts of fly ash, 2 parts of 150 mesh quartz sand, 0.002 parts of polycarboxylic acid high-performance water reducing agent, and 4 parts of water;

[0031] The gradation of the water-reactive cold mix asphalt mixture is SPAC-16, and its composition is shown in Table 1 below;

[0032] Table 1 SPAC-16 asphalt mixture gradation composition

[0033]

[0034]

[0035] The method for preparing the poured semi-flexible concrete based on the water-reactive cold mix asphalt mixture of the present embodiment comprises the following steps:

[0036] Step 1: Heat No. 70 base asphalt to 140°C to 150°C, add dimethylformamide, tung oil, and curing agent calcium hydroxide to the No. 70 base asphalt and mix evenly to prepare water-reactive cold mix asphalt;

[0037] Step 2: The water-reactive cold-mix asphalt prepared in step 1 is mixed evenly with mineral materials manually or by a mixing machine to prepare a water-reactive cold-mix asphalt mixture;

[0038] Step 3: Place the water-reactive cold-mix asphalt mixture prepared in step 2 into a rutting plate test mold, spray water on the surface, and then roll and shape it, and cure it at room temperature for 12 hours to obtain a rutting plate specimen with a void ratio of 25%;

[0039] Step 4: Mix silicate cement, sulphoaluminate cement, fly ash and 150 mesh quartz sand evenly, then add a mixture of polycarboxylic acid high performance water reducer and water, and stir for 3 minutes at a speed of not less than 1200 r / min to obtain cement grouting material;

[0040] Step 5: Use plasticine or plastic tape to seal the gaps around the rutting plate specimen prepared in step 3, and then pour the cement grouting material obtained in step 4 onto the sealed surface of the rutting plate specimen, so that the cement grouting material flows into the skeleton gap of the rutting plate specimen under the action of its own weight until it is completely impermeable;

[0041] Step 6: Use a scraper or brush to clean the excess cement grouting material on the surface of the rutting plate specimen in step 5 until 10 mm to 20 mm of coarse aggregate is exposed on the surface, and then maintain at room temperature for not less than 12 hours to obtain a poured semi-flexible concrete specimen based on a water-reactive cold mix asphalt mixture.

[0042] Example 2

[0043] The difference between this embodiment and embodiment 1 is that the poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture is made of the following raw materials in parts by weight: 3 parts of water-reactive cold-mix asphalt, 100 parts of mineral material, 11 parts of cement grouting material, and 4.5 parts of water; by weight, 1.5 parts of reaction medium water is sprayed when the water-reactive cold-mix asphalt mixture composed of water-reactive cold-mix asphalt and mineral material is formed;

[0044] The cement grouting material is made of the following raw materials in parts by weight: 3 parts of silicate cement, 3 parts of sulphoaluminate cement, 0.5 parts of fly ash, 3 parts of 100 mesh quartz sand, 0.003 parts of polycarboxylic acid high-performance water reducing agent, and 5 parts of water.

[0045] Example 3

[0046] The difference between this embodiment and embodiment 1 is that the poured semi-flexible concrete based on water-reactive cold-mix asphalt mixture is made of the following raw materials in parts by weight: 4 parts of water-reactive cold-mix asphalt, 100 parts of mineral material, 12 parts of cement grouting material, and 5 parts of water; by weight, 2 parts of reaction medium water is sprayed on the water-reactive cold-mix asphalt mixture composed of water-reactive cold-mix asphalt and mineral material during molding;

[0047] The cement grouting material is made of the following raw materials in parts by weight: 4 parts of silicate cement, 4 parts of sulphoaluminate cement, 0.3 parts of fly ash, 3 parts of 200-mesh quartz sand, 0.002 parts of polycarboxylic acid high-performance water reducing agent, and 4 parts of water.

[0048] The poured semi-flexible concrete specimens based on water-reactive cold mix asphalt mixtures prepared in Examples 1 to 3 of the present invention were subjected to a 60°C rutting test in accordance with the relevant test provisions of the Ministry of Communications standard JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures for Highway Engineering", and the results are shown in Table 2 below.

[0049] Table 2 Test results of the anti-rutting performance of poured semi-flexible concrete based on water-reactive cold mix asphalt mixture

[0050]

[0051]

[0052] As can be seen from Table 2, the anti-rutting performance of the poured semi-flexible concrete based on the water-reactive cold-mix asphalt mixture of the present invention far exceeds the technical level of the hot-mix modified asphalt mixture, and can be widely used in the maintenance and treatment of rutting diseases of asphalt pavements in various climatic regions.

[0053] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture, characterized in that: The invention is made of the following raw materials in parts by weight: 3-4 parts of water-reactive cold-mix asphalt, 100 parts of mineral material, 10-12 parts of cement grouting material, and 4-5 parts of water. When the water-reactive cold-mix asphalt mixture composed of the water-reactive cold-mix asphalt and the mineral material is formed, 1-2 parts of reaction medium water is sprayed.

2. The pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture according to claim 1, characterized in that: The water-reactive cold-mix asphalt is made from the following raw materials in parts by weight: 0.5 parts of dimethylformamide, 0.3 parts of tung oil, 3 parts of base asphalt, and 0.02 parts of curing agent.

3. The pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture according to claim 1, characterized in that: The mineral material is composed of the following raw materials in parts by weight: 19 parts of coarse aggregate of 10 mm to 20 mm, 74 parts of coarse aggregate of 5 mm to 10 mm, 5 parts of fine aggregate of 0 to 3 mm, and 2 parts of mineral powder.

4. The pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture according to claim 1, characterized in that: By weight, 2 parts of reaction medium water are sprayed when the water-reactive cold-mix asphalt mixture is used to form a rutting plate specimen.

5. The pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture according to claim 1, characterized in that: The cement grouting material is made of the following raw materials in parts by weight: 3-4 parts of silicate cement, 3-4 parts of sulphoaluminate cement, 0.2-0.5 parts of fly ash, 2-3 parts of quartz sand, 0.002-0.003 parts of water reducing agent and 4-5 parts of water.

6. The pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture according to claim 1, characterized in that: The gradation of the water-reactive cold-mix asphalt mixture is SPAC-16, and the void ratio is 20% to 28%.

7. The pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture according to claim 5, characterized in that: The particle size of the quartz sand is 100-200 meshes.

8. The pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture according to claim 5, characterized in that: The water reducing agent is a polycarboxylic acid high performance water reducing agent.

9. A method for preparing pourable semi-flexible concrete based on water-reactive cold mix asphalt mixture according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: Step 1: Heat the base asphalt to 140°C to 150°C, add dimethylformamide, tung oil and curing agent into the base asphalt and stir evenly to prepare water-reactive cold mix asphalt; Step 2: The water-reactive cold-mix asphalt prepared in step 1 is mixed evenly with mineral materials manually or by a mixing machine to prepare a water-reactive cold-mix asphalt mixture; Step 3: Place the water-reactive cold-mix asphalt mixture prepared in step 2 into a rutting plate test mold, spray water on the surface, and then roll and shape it, and cure it at room temperature for 12 hours to obtain a rutting plate specimen with a void ratio of 20% to 28%; Step 4: Mix the silicate cement, sulphoaluminate cement, fly ash and quartz sand evenly, then add the mixed solution of water reducer and water, and stir at a speed of not less than 1200 r / min for not less than 2 min to obtain cement grouting material; Step 5: Use plasticine or plastic tape to seal the gaps around the rutting plate specimen prepared in step 3, and then pour the cement grouting material obtained in step 4 onto the sealed surface of the rutting plate specimen, so that the cement grouting material flows into the skeleton gap of the rutting plate specimen under the action of its own weight until it is completely impermeable; Step 6. Use a scraper or brush to clean the excess cement grouting material on the surface of the rutting plate specimen in step 5 until 10mm to 20mm of coarse aggregate is exposed on the surface, and then cure at room temperature for not less than 12 hours.

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