阅读说明：本技术 一种水泥稳定碎石微裂添加剂及其应用 (Cement stabilized macadam microcrack additive and application thereof ) 是由 权磊 田波 赵源 陆相霖 李立辉 李思李 何哲 谢晋德 侯荣国 张盼盼 刘洁 于 2020-07-22 设计创作，主要内容包括：本发明公开一种水泥稳定碎石微裂添加剂及其应用,该微裂添加剂包括主组分、辅助组分和水；所述的主组分选自脂肪酸甘油酯、聚氧乙烯醚-20油酰篦麻醇酸酯、水性双酚A环氧树脂乳液中的一种或者多种组合；所述的辅助组分选自矿物纤维、固化剂、乳化剂、稳定剂、分散剂中的一种或者多种组合。本发明的微裂添加剂掺加到水泥稳定碎石材料后,骨料-砂浆界面粘结会产生随机弱化,由此将砂浆相的收缩随机分散在骨料体系之间,避免传统半刚性基层中裂纹会扩展连通形成长宽裂缝；能够彻底解决一直以来传统水泥稳定碎石长宽裂缝和错台引发的系列问题；避免了后期的开挖式修复措施,从全寿命周期大大节省工程养护资金投入,全寿命成本经济效益显著。(The invention discloses a cement stabilized macadam microcrack additive and application thereof, wherein the microcrack additive comprises a main component, an auxiliary component and water; the main component is selected from one or more of fatty glyceride, polyoxyethylene ether-20 oleoyl ricinoleate and water-based bisphenol A epoxy resin emulsion; the auxiliary component is selected from one or more of mineral fiber, curing agent, emulsifier, stabilizer and dispersant. After the microcrack additive is doped into a cement stabilized macadam material, the bonding of an aggregate-mortar interface can be randomly weakened, so that the shrinkage of a mortar phase is randomly dispersed among aggregate systems, and the phenomenon that cracks in a traditional semi-rigid base layer can be expanded and communicated to form long and wide cracks is avoided; the series problems caused by long and wide cracks and slab staggering of the traditional cement stabilized macadam can be thoroughly solved; the later excavation type repairing measures are avoided, the engineering maintenance capital investment is greatly saved from the whole life cycle, and the whole life cost and economic benefits are remarkable.)

1. The cement stabilized macadam microcrack additive is characterized by comprising a main component, an auxiliary component and water; the main component is selected from one or more of fatty glyceride, polyoxyethylene ether-20 oleoyl ricinoleate and water-based bisphenol A epoxy resin emulsion; the auxiliary component is selected from one or more of mineral fiber, curing agent, emulsifier, stabilizer and dispersant.

2. The cement stabilized macadam microcrack additive of claim 1, wherein: the main components are fatty glyceride and polyoxyethylene ether-20 oleoyl ricinoleate; the auxiliary component is an emulsifier; the weight portions of the components are respectively as follows based on 100 weight portions: 45-50 parts of fatty glyceride, 8-10 parts of polyoxyethylene ether-20-oleoyl ricinoleate, 20-25 parts of emulsifier and the balance of water.

3. The cement stabilized macadam microcrack additive of claim 1, wherein: the main component is water-based bisphenol A epoxy resin emulsion; the auxiliary components are a curing agent and a stabilizing agent; the weight portions of the components are respectively as follows based on 100 weight portions: 18-35 parts of water-based bisphenol A epoxy resin emulsion, 10-16 parts of curing agent, 5-8 parts of stabilizer and the balance of water.

4. The cement stabilized macadam microcrack additive of claim 1, wherein: the main components are fatty glyceride, polyoxyethylene ether-20 oleoyl ricinoleate and aqueous bisphenol A epoxy resin emulsion; the auxiliary components comprise mineral fibers, a curing agent, an emulsifier, a stabilizer and a dispersing agent; the weight portions of the components are respectively as follows based on 100 weight portions: 11-16 parts of fatty glyceride, 2-3 parts of polyoxyethylene ether-20-oleoyl ricinoleate, 8-12 parts of water-based bisphenol A epoxy resin emulsion, 1-2 parts of mineral fiber, 4-6 parts of curing agent, 6-10 parts of emulsifier, 4-8 parts of stabilizer, 4-7 parts of dispersant and the balance of water.

5. The cement stabilized macadam microcrack additive of claim 1, wherein: the curing agent adopts diethylenetriamine; the emulsifier adopts tallow tetramine; the stabilizer is polyacrylamide; the dispersing agent adopts sodium dodecyl sulfate.

6. A system for metering a microcracking additive for cement stabilized macadams according to any of claims 1 to 5, characterized in that: the device comprises a microcrack additive storage barrel (1), an anticorrosive submersible pump (2), an electromagnetic valve, a numerical control flowmeter (3), a valve controller (4), a supercharger (6) and an atomizing spray head (7); the anti-corrosion submersible pump (2) is arranged at the bottom of the microcrack additive storage barrel (1); the atomizing spray head (7) is arranged 20-50 cm above a conveyor belt (8) of a broken stone blanking bin with the particle size larger than 10 mm; the atomizing spray head (7) is connected with the anticorrosive submersible pump (2) in the microcrack additive storage barrel (1) through a connecting pipeline (5); the electromagnetic valve and the numerical control flowmeter (3) are arranged on a connecting pipeline between the atomizing nozzle (7) and the anticorrosive submersible pump (2); the supercharger (6) is arranged on a connecting pipeline close to the atomizing nozzle (7); the valve controller (4) is respectively connected with the electromagnetic valve, the numerical control flowmeter (3) and the supercharger (6).

7. The system of claim 6, wherein the system further comprises: the atomizing nozzle (7) is arranged 20cm above a conveyor belt (8) of a broken stone discharging bin with the particle size of 10-25 mm.

8. Use of a microcrack additive according to any one of claims 1 to 5 in microcrackable cement stabilized macadam foundation construction.

9. Use according to claim 8, characterized in that: the dosage of the cement stabilized macadam microcrack additive is that the total specific surface area A of the macadam with the grain diameter of more than 10mm in each ton of cement stabilized macadam is multiplied by the total weight M multiplied by 0.005 of the macadam with the grain diameter of more than 10 mm.

Technical Field

The invention belongs to the technical field of road materials and pavement structures, and particularly relates to a cement stabilized macadam microcrack additive and application thereof.

Background

The cement stabilized macadam (semi-rigid) base course is the most commonly used load-bearing base course type of road surfaces of various grades in China, but the cement stabilized macadam base course is easy to generate shrinkage cracks and plate fracture, so that a series of secondary diseases such as reflection cracks are induced on an asphalt surface layer, and the deterioration of the performance of the road surface is accelerated. The cracks of the base layer are concealed, the detection and treatment cost is high, and once the cracks are usually destroyed, the cracks need to be dug and rebuilt in a 'rifling and belly breaking' mode, so that the cracks are an aeipathia which influences the long life of the semi-rigid base layer asphalt pavement.

For a long time, road workers have tried to improve the self-resistance of cement stabilized macadam from various angles (framework dense structure, heavy compaction, expansion compensation, vibration stirring, etc.) to meet the requirements of load and environmental effects. However, from the perspective of concrete materials, cement consumption of the cement-stabilized macadam is small (about 5%), mortar cement is large (about 1.0%), aggregate strength and particle type are poor, parameters such as strength, modulus and shrinkage coefficient of the cement-stabilized macadam formed by rolling are in a complex combined state, and nonuniformity of the cement-stabilized macadam on a microscopic scale is very obvious due to a large amount of weak bonding and initial defects among particles. The improvement range of homogeneity through materials and construction technology is far lower than the self-nonuniformity, the superposition of the support of a lying layer is nonuniform, and the plate fracture of the cement stabilized macadam base layer under the long-term action of load is inevitable; meanwhile, weak bonding caused by the defects of the traditional cement stabilized macadam aggregate-mortar interface is not weak enough, so that random cracking can be realized in the temperature shrinkage and drying process, and the plate body property of the cement stabilized macadam base layer is reserved to a certain extent, so that long and wide through cracks are easily formed. The traditional scheme of increasing the cement dosage and improving the crack resistance of cement stabilized macadam can simultaneously increase the shrinkage coefficient of the macadam, and natural cracking or artificial pre-cutting cracks can generate long and wide cracks to induce reflection cracks and sink into bottlenecks in research.

Under the background, the design idea of the cement stabilized macadam material with controllable microcracks is urgently needed to be provided, the plate body property of the cement stabilized macadam base layer is weakened through weakening the bonding of an aggregate-mortar interface, the miniaturization of crack width and length is realized, and the difference of slab staggering and modulus is weakened slightly.

Disclosure of Invention

The invention aims to provide a microcrack additive for cement stabilized macadam and application thereof aiming at the defects in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a cement stabilized macadam microcrack additive comprises a main component, an auxiliary component and water; the main component is selected from one or more of fatty glyceride, polyoxyethylene ether-20 oleoyl ricinoleate and water-based bisphenol A epoxy resin emulsion; the auxiliary component is selected from one or more of mineral fiber, curing agent, emulsifier, stabilizer and dispersant.

According to the preferable scheme of the micro-cracking additive for the cement stabilized macadam, the main components are fatty glyceride and polyoxyethylene ether-20 oil acyl ricinoleate; the auxiliary component is an emulsifier; the weight portions of the components are respectively as follows based on 100 weight portions: 45-50 parts of fatty glyceride, 8-10 parts of polyoxyethylene ether-20-oleoyl ricinoleate, 20-25 parts of emulsifier and the balance of water.

The fatty glyceride, the polyoxyethylene ether-20 oil acyl ricinoleate, the emulsifier and the drinking water are sheared and stirred at a high speed to form aqueous emulsion, and the aqueous emulsion is sprayed on the surface of the aggregate to form the low-modulus coating.

According to the preferable scheme of the cement stabilized macadam microcrack additive, the main component is water-based bisphenol A epoxy resin emulsion; the auxiliary components are a curing agent and a stabilizing agent; the weight portions of the components are respectively as follows based on 100 weight portions: 18-35 parts of water-based bisphenol A epoxy resin emulsion, 10-16 parts of curing agent, 5-8 parts of stabilizer and the balance of water.

The aqueous bisphenol A epoxy resin emulsion, the curing agent, the stabilizer and water are subjected to high-speed shearing and stirring to form the aqueous emulsion, and the aqueous emulsion is sprayed on the surface of the aggregate to form the high-modulus coating.

According to the preferable scheme of the micro-cracking additive for the cement stabilized macadam, the main components are fatty glyceride, polyoxyethylene ether-20 oil acyl ricinoleate and water-based bisphenol A epoxy resin emulsion; the auxiliary components comprise mineral fibers, a curing agent, an emulsifier, a stabilizer and a dispersing agent; the weight portions of the components are respectively as follows based on 100 weight portions: 11-16 parts of fatty glyceride, 2-3 parts of polyoxyethylene ether-20-oleoyl ricinoleate, 8-12 parts of water-based bisphenol A epoxy resin emulsion, 1-2 parts of mineral fiber, 4-6 parts of curing agent, 6-10 parts of emulsifier, 4-8 parts of stabilizer, 4-7 parts of dispersant and the balance of water.

The fatty glyceride, polyoxyethylene ether-20 oleoyl ricinoleate, water-based bisphenol A epoxy resin emulsion, mineral fiber, curing agent, emulsifier, stabilizer, dispersant and water are sheared and stirred at high speed to form water-based emulsion which is sprayed on the surface of the aggregate.

In the invention, the selected fatty glyceride has low melting point and can keep fluid state at normal temperature, and the polyoxyethylene ether-20 oleoyl ricinoleic acid ester is a nonionic liquid emulsifier, has the characteristic of balance between oleophylic value and hydrophilic value, and can ensure that the fatty glyceride is uniformly and stably dispersed in the aqueous solution. The emulsion formed by the fatty glyceride, the polyoxyethylene ether-20 oleoyl ricinoleate, the emulsifier and the water has mechanical characteristics which do not change along with the temperature and the cement hydration process, and a thin layer structure with lower modulus is formed in the cement stabilized macadam. The aqueous bisphenol A epoxy resin emulsion has mature industrial production and stable performance, and the emulsion formed by the aqueous bisphenol A epoxy resin emulsion and the curing agent and the stabilizing agent gradually starts a curing reaction after the cement stabilized macadam is added, and finally a thin-layer structure with the modulus higher than that of cement mortar is formed in the cement stabilized macadam.

The invention further discloses that the curing agent adopts diethylenetriamine; the emulsifier adopts tallow tetramine; the stabilizer is polyacrylamide; the dispersing agent adopts sodium dodecyl sulfate.

The addition of the microcrack additive needs to add a special metering system in a conventional cement stabilized macadam mixing station; the invention also provides a metering system of the cement stabilized macadam microcrack additive, which comprises a microcrack additive storage barrel, an anticorrosive submersible pump, an electromagnetic valve, a numerical control flowmeter, a valve controller, a supercharger and an atomizing spray head; the anticorrosion submersible pump is arranged at the bottom of the microcrack additive storage barrel; the atomizing spray head is arranged 20-50 cm above a conveyor belt of a broken stone discharging bin with the particle size larger than 10 mm; the atomization nozzle is connected with an anticorrosive submersible pump in the microcrack additive storage barrel through a connecting pipeline; the electromagnetic valve and the numerical control flowmeter are arranged on a connecting pipeline between the atomizing spray head and the anticorrosive submersible pump; the supercharger is arranged on a connecting pipeline close to the atomizing nozzle; the valve controller is respectively connected with the electromagnetic valve, the numerical control flowmeter and the supercharger.

Further preferably, the atomizing nozzle is arranged 20cm above a conveyor belt of a broken stone discharging bin with the particle size of 10-25 mm.

Further, the valve controller is an integrated controller established based on a PLC or MCU or ARM control chip.

The microcrack additive for cement stabilized macadam is applied to the construction of a microcrack cement stabilized macadam base.

In the construction application, the proportion of the cement stabilized macadam added with the microcrack additive is selected according to the current technical rules for constructing highway pavements and foundations (JTG/T F20) and the test procedures for stabilizing materials of inorganic binders in highway engineering (JTG E51) on aggregate grading curves, the cement dosage is determined, the optimal water consumption is determined, the doping amount of the microcrack additive is determined, and the like.

Preferably, the dosage of the micro-cracking additive for cement stabilized macadam is that the total specific surface area A of the macadam with the particle size of more than 10mm in each ton of cement stabilized macadam is multiplied by the total weight M multiplied by 0.005 of the macadam with the particle size of more than 10 mm.

Preferably, the aggregate grading curve is of a skeleton compact type, and when the maximum aggregate particle size is 37.5mm, the 26.5mm pass rate is 60%, the 13.2mm pass rate is 55%, and the 0.3mm pass rate is 5%; when the maximum grain size of the aggregate is 26.5mm, the 16mm grade passage rate is 60%, the 9.5mm grade passage rate is 55% and the 0.3mm grade passage rate is 5%.

Preferably, the cement dosage of the cement-stabilized macadam subbase is 5%, and the cement dosage of the cement-stabilized macadam base is 6% -7%.

The construction method of the microcrackable cement stabilized macadam foundation is carried out according to the related technical requirements of the existing technical Specification for highway pavement foundation construction (JTG/T F20), and has no special requirements.

The invention has the advantages that:

when the cement stabilized macadam material prepared by the microcrack additive is added, the bonding of the aggregate-mortar interface can be randomly weakened, so that the shrinkage of a mortar phase can be randomly dispersed among aggregate systems, and the phenomenon that cracks in a traditional semi-rigid base layer can be expanded and communicated to form long and wide cracks is avoided; the reduction of the bearing capacity of the cement stabilized macadam by interface weakening is compensated by a skeleton embedding and squeezing structure with stronger internal friction resistance formed by aggregate and reinforced mortar, the cement stabilized macadam with interface weakening still has the integral characteristic of no wide crack in macroscopic view, and the series problems caused by long and wide cracks and slab staggering of the traditional cement stabilized macadam can be thoroughly solved; the later excavation type repairing measures are avoided, the engineering maintenance capital investment is greatly saved from the whole life cycle, and the whole life cost and economic benefits are remarkable.

Drawings

FIG. 1 is a schematic diagram of a metrology system in accordance with an embodiment of the present invention.

FIG. 2 is a graph of a road segment fracture without the addition of a microcracking additive.

FIG. 3 is a graph showing the effect of microcracking at locations of increased fines after incorporation of a microcracking additive.

FIG. 4 is a graph of the effect of normal road sections after the addition of a microcracking additive.

FIG. 5 is a schematic illustration of a road section microcrack width after incorporation of a microcracking additive.

Reference numerals: 1-a microcrack additive storage barrel, 2-an anticorrosive submersible pump, 3-an electromagnetic valve and a numerical control flowmeter, 4-a valve controller, 5-a connecting pipeline, 6-a supercharger, 7-an atomizing nozzle, 8-a conveyor belt and 9-a broken stone discharging bin.

Detailed Description

The invention is further described below with reference to the accompanying drawings.