Storage type reactive asphalt mixture and preparation method and storage life evaluation method thereof

Abstract

The invention provides a storage type reactive asphalt mixture and a preparation method and a storage life evaluation method thereof, and belongs to the technical field of road engineering materials. The storage type reactive asphalt mixture provided by the invention comprises the reactive binder composition, and the reactive viscosity reducer can reduce the viscosity and improve the mechanical properties of the storage type reactive asphalt mixture. The aggregate forms a load-bearing skeleton structure which is one of the main sources of the strength after the mixture is cured. The inert rheological modifier reduces the reaction activity of the storage type reactive asphalt mixture; moreover, the inert rheological modifier adjusts the viscosity of the storage type asphalt mixture through physical action, improves the fluidity and prolongs the storage time of the storage type reaction asphalt mixture. The invention further discloses a method for quantitatively evaluating and predicting the storage stability of the mixture through Fourier transform infrared spectroscopic analysis in combination with physical properties, and the problem that an effective quality evaluation means is lacked in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering materials, and particularly relates to a storage type reaction asphalt mixture, a preparation method thereof and a storage life evaluation method. BACKGROUND

[0002] A road surface pit refers to a concave, damaged or cracked area on a road surface, which is usually in a pit shape and is one of the most common road damage forms. At present, the methods for repairing the road surface pit mainly include a hot repair method and a cold repair method. The reaction asphalt mixture is a material capable of being used for cold repair or cold paving, and is concerned due to advantages such as energy saving, environmental protection and convenient construction.

[0003] The reaction asphalt mixture generally comprises a reaction active component and a latent alkaline curing agent, and a curing reaction is generated under specific conditions such as moisture excitation to achieve the repair of the road surface pit. However, in the actual production, transportation and storage process, the existing reaction asphalt mixture generally faces the problem of poor storage stability. The reasons are as follows: (1) the raw materials for preparing the reaction asphalt mixture inevitably contain a small amount of moisture, which provides conditions for the slow chemical reaction of the reaction asphalt mixture; (2) the temperature in the production and mixing process of the reaction asphalt mixture accelerates the reaction of the reaction asphalt mixture; (3) under the condition of sealed storage, especially in the summer high-temperature environment or for a long time, the internal heat is difficult to dissipate, which causes the chemical reaction of the reaction asphalt mixture to occur prematurely and too quickly, so that the reaction asphalt mixture is thickened, hardened or even completely cured, which greatly shortens the effective use period and the workable window of the product.

[0004] Therefore, it has become a technical problem to be solved in the field to provide a storage type reaction asphalt mixture with long-term storage stability. SUMMARY

[0005] The present application aims to provide a storage type reaction asphalt mixture with long-term storage stability, a preparation method thereof and a storage life evaluation method.

[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions: The present application provides a storage type reaction asphalt mixture, which comprises the following components in percentage by mass: a reaction type binder composition 4-8%; aggregate 92-96%; and a latent alkaline curing agent 0.5-5%.

[0007] The reaction type binder composition comprises, in 100 parts by weight: a bituminous binder 40-80 parts, a reaction type viscosity reducer 15-50 parts, an inert rheological modifier 1-20 parts and a functional additive 0.1-5 parts. The reactive viscosity reducer comprises at least one of saturated fatty acids and unsaturated fatty acids. The latent alkaline curing agent comprises an oxide of an alkaline earth metal and / or a hydroxide of an alkaline earth metal.

[0008] Preferably, the asphalt binder comprises at least one of road petroleum asphalt and modified asphalt.

[0009] Preferably, the reactive viscosity reducer comprises at least one of C8-C24 saturated fatty acids, C8-C24 unsaturated fatty acids and plant oil foot refining fatty acids.

[0010] Preferably, the inert rheological modifier comprises at least one of mineral oil, rubber oil, synthetic ester, plant oil and waste oil refining product.

[0011] Preferably, the functional auxiliary agent comprises a coupling agent and / or an antioxidant.

[0012] Preferably, the oxide of the alkaline earth metal comprises calcium oxide and / or magnesium oxide; and the hydroxide of the alkaline earth metal comprises calcium hydroxide.

[0013] Preferably, the aggregate is dense type grading or intermittent grading.

[0014] The present application also provides a preparation method of the storage type reactive asphalt mixture as described in the above technical solution, comprising the following steps: mixing the asphalt binder, the reactive viscosity reducer, the inert rheological modifier and the functional auxiliary agent to obtain a reactive binder composition; mixing the dried aggregate, the latent alkaline curing agent and the reactive binder composition to obtain the storage type reactive asphalt mixture.

[0015] The present application also provides an evaluation method of the storage life of the storage type reactive asphalt mixture, comprising the following steps: (1) determining the maximum allowable reaction value R limit The to-be-tested asphalt mixture is stored under the first simulated storage condition; the to-be-tested asphalt mixture is the storage type reactive asphalt mixture as described in the above technical solution or the storage type reactive asphalt mixture prepared by the preparation method as described in the above technical solution: i) performing a penetration strength test on a part of the sample to obtain the penetration strength of the sample under different storage times; ii) dissolving another part of the sample, and then filtering to obtain a filtrate; drying the filtrate to obtain recovered binder at different storage times; detecting the recovered binder at different storage times by Fourier transform infrared spectroscopy, and calculating the reaction value of the recovered binder at different storage times according to formula (1): R(t) = [(A(0)-A(t)) / A(0)]x100% Formula (1) In formula (1), R(t) is the reaction value of the recovered binder at different storage times; A(0) is the signal intensity at 1730 cm -1 of the recovered binder with a storage time of 0; A(t) is the signal intensity at 1730 cm -1 of the recovered binder at different storage times; Taking the penetration strength of the sample at different storage times as the abscissa, and the reaction value R(t) of the recovered binder at different storage times as the ordinate, a corresponding relationship between the penetration strength and R(t) is established; according to the corresponding relationship between the penetration strength and R(t), the R(t) corresponding to the critical penetration strength value is used as the maximum allowable reaction value R limit ; (2) Monitoring the change of the reaction value during storage The asphalt mixture to be tested is stored under the second simulated storage condition, and a part of the sample is taken out at different storage times. The reaction value R(t)' of the sample at different storage times is determined according to the method of step ii), and a regular curve of the reaction value R(t)' changing with time under the second simulated storage condition is obtained; (3) Predicting the storage life The regular curve of the reaction value changing with time under the second simulated storage condition obtained in step (2) is fitted or extrapolated by a mathematical model, and the time required for the predicted reaction value to reach the maximum allowable reaction value determined in step (1) is predicted as the predicted storage life of the asphalt mixture to be tested under the second simulated storage condition. R limit R limit

[0016] Preferably, the temperature of the first simulated storage condition in step (1) is 60-120°C.

[0017] ​​The application provides a storage type reactive asphalt mixture, which comprises the following components in percentage by mass: 4-8% of a reactive binder composition; 92-96% of aggregate and 0.5-5% of a latent alkaline curing agent; the reactive binder composition comprises 40-80 parts by weight of asphalt binder, 15-50 parts by weight of a reactive viscosity reducer, 1-20 parts by weight of an inert rheological modifier and 0.1-5 parts by weight of a functional additive, with 100 parts by weight of the reactive binder composition; the reactive viscosity reducer comprises saturated fatty acid and / or unsaturated fatty acid; and the latent alkaline curing agent comprises oxide of alkaline earth metal and / or hydroxide of alkaline earth metal. The storage type reactive asphalt mixture provided by the application comprises the reactive binder composition, the reactive viscosity reducer in the reactive binder composition comprises at least one of fatty acid and unsaturated fatty acid, the reactive viscosity reducer can reduce the viscosity, the carboxylic acid in the reactive viscosity reducer can also participate in the curing of the storage type reactive asphalt mixture, and the mechanical properties of the storage type reactive asphalt mixture after curing are improved. The storage type reactive asphalt mixture provided by the application comprises the inert rheological modifier, the inert rheological modifier reduces the reactivity of the storage type reactive asphalt mixture; and the inert rheological modifier adjusts the viscosity of the storage type asphalt mixture through physical action, improves the flowability, can continue to store when encountering a small amount of activator (water), improves the tolerance of the system to the pre-reaction degree, and prolongs the storage time of the storage type reactive asphalt mixture. The storage type reactive asphalt mixture provided by the application comprises the aggregate, which forms a load-bearing skeleton structure and is the main source of the strength of the mixture after curing. The storage type reactive asphalt mixture provided by the application comprises the latent alkaline curing agent, the latent alkaline curing agent has good stability before encountering the activator, and can release alkaline substances after encountering the activator. The results of the examples show that the stability of the storage type reactive asphalt mixture provided by the application is obviously improved compared with the reactive asphalt mixture without the inert rheological modifier. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The device for the penetration strength test used in example 3 of the application; Figure 2 The photo of the rotary evaporator used in example 3 of the application; Figure 3 The infrared spectrograms of the recovered binder at the storage time of 0h and 24h in example 3 of the application; Figure 4 The corresponding relationship diagram of the reaction value and the penetration strength obtained under the first simulated storage condition (80℃) in test example 1 of the application; Figure 5 The curve diagram of the reaction value changing with the storage time obtained under the first simulated storage condition (80℃) in test example 1 of the application; Figure 6The reaction value of Test Example 1 of the present application under the second simulated storage condition (25℃ normal temperature) is plotted against the storage time. DETAILED DESCRIPTION

[0019] The present application provides a storage type reaction asphalt mixture, comprising the following components in percentage by mass: 4-8% of a reaction type binder composition; 92-96% of aggregate; 0.5-5% of a latent alkaline curing agent; The reaction type binder composition comprises, in 100 parts by weight: 40-80 parts of asphalt binder, 15-50 parts of reaction type viscosity reducer, 1-20 parts of inert rheological modifier, and 0.1-5 parts of functional auxiliary agent; The reaction type viscosity reducer comprises at least one of saturated fatty acid and unsaturated fatty acid. The latent alkaline curing agent comprises oxide of alkaline earth metal and / or hydroxide of alkaline earth metal.

[0020] The storage type reaction asphalt mixture provided by the present application comprises 4-8% of reaction type binder composition by mass. As an embodiment of the present application, the reaction type binder composition can be 4%, 5%, 6%, 7% or 8% by mass. The present application uses reaction type binder composition as the adhesive main body of storage type reaction asphalt mixture.

[0021] The reaction type binder composition provided by the present application comprises 40-80 parts of asphalt binder by weight of the reaction type binder composition. As an embodiment of the present application, the asphalt binder can be 40 parts, 50 parts, 60 parts, 70 parts or 80 parts by weight. In the present application, the asphalt binder preferably comprises at least one of road petroleum asphalt and modified asphalt. In the embodiment of the present application, the road petroleum asphalt can be 70# asphalt; the modified asphalt can be SBS modified asphalt. The present application does not have special limitation on the source of the road petroleum asphalt and modified asphalt, and any commercially available product known to those skilled in the art can be used. In the embodiment of the present application, the source of the road petroleum asphalt and modified asphalt can be Zhenhai Refining and Chemical. The present application uses asphalt binder as the main adhesive component of storage type reaction asphalt mixture.

[0022] The reactive binder composition provided by the present application comprises 15-50 parts of reactive viscosity reducer, based on 100 parts of the reactive binder composition. As an embodiment of the present application, the reactive viscosity reducer can be 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts or 50 parts. In the present application, the reactive viscosity reducer comprises at least one of saturated fatty acid and unsaturated fatty acid. The reactive viscosity reducer used in the present application can reduce viscosity, and the carboxylic acid therein can participate in the curing of the storage-type reactive asphalt mixture, thereby improving the mechanical properties of the storage-type reactive asphalt mixture after curing.

[0023] In the present application, the reactive viscosity reducer preferably comprises at least one of C8-C24 saturated fatty acid, C8-C24 unsaturated fatty acid and plant oil foot refining fatty acid, and more preferably at least one of oleic acid, linoleic acid, linolenic acid, palmitic acid and stearic acid. In the embodiment of the present application, the reactive viscosity reducer is preferably an industrial-grade mixed fatty acid, which is preferably a mixture comprising C8-C24 saturated and unsaturated fatty acid, and the physicochemical properties thereof meet at least one or more of the following indexes: acid value range of 180-210 mgKOH / g, iodine value of 60-150 g / 100g, and saponification value range of 150-220 mgKOH / g. The above-mentioned reactive viscosity reducer used in the present application has at least one carboxyl functional group, which can not only reduce the viscosity of the system and improve the mechanical strength of the storage-type reactive asphalt mixture after curing, but also can be used as a characteristic group for storage life evaluation, thereby improving the accuracy of the storage life.

[0024] The reactive binder composition provided by the present application comprises 1-20 parts of inert rheological modifier, based on 100 parts of the reactive binder composition. As an embodiment of the present application, the inert rheological modifier can be 1 part, 5 parts, 10 parts, 15 parts or 20 parts. In the present application, the inert rheological modifier can reduce the reactivity of the storage-type reactive asphalt mixture; and the inert rheological modifier can adjust the viscosity of the storage-type asphalt mixture through physical action, thereby improving the flowability, enabling the system to continue to store when encountering a trace amount of activator (water), improving the tolerance of the system to the degree of pre-reaction, and prolonging the storage time of the storage-type reactive asphalt mixture.

[0025] In the present application, the inert rheological modifier preferably comprises at least one of mineral oil, rubber oil, synthetic ester, vegetable oil and waste oil extract. In the present application, the mineral oil is preferably naphthenic oil; the rubber oil is preferably aromatic oil; the synthetic ester is preferably at least one of fatty acid ester and polybasic acid ester. The vegetable oil is preferably at least one of palm oil, sunflower oil, rapeseed oil and soybean oil. The inert rheological modifier used in the present application is basically free of functional groups capable of rapidly reacting with latent alkaline curing agent, and has good inertness. The present application does not have special limitations on the source of the inert rheological modifier, and conventional commercially available products can be used. In the embodiments of the present application, the source of the inert rheological modifier can be aromatic oil produced by Hebei Oujia Lubricating Oil Co., Ltd.

[0026] The reactive binder composition provided by the present application comprises 0.1-5 parts by weight of functional additives, based on 100 parts by weight of the reactive binder composition. As an embodiment of the present application, the parts by weight of the functional additives can be 0.1, 0.5, 1, 2, 3, 4 or 5. In the present application, the functional additives preferably comprise coupling agents and / or antioxidants. The present application can improve the weather resistance of the storage type reactive asphalt mixture by adding functional additives.

[0027] In the present application, the coupling agent is preferably a silane coupling agent, which preferably comprises at least one of alkoxysilane, epoxy silane, amino silane and methacryloyloxy silane. In the present application, the alkoxysilane is preferably n-dodecyl triethoxysilane; the epoxy silane is preferably γ-glycidoxypropyltrimethoxysilane (KH-560); the amino silane is preferably γ-aminopropyl triethoxysilane or γ-aminopropyl trimethoxysilane (KH-550); and the methacryloyloxy silane is preferably γ-methacryloyloxypropyl trimethoxysilane or γ-methacryloyloxypropyl triethoxysilane (KH-570).

[0028] In the present application, the antioxidant preferably comprises at least one of hindered phenolic antioxidant, phosphite antioxidant and sulfur ester antioxidant.

[0029] The storage type reactive asphalt mixture provided by the present application comprises 92-96% by mass of aggregate. As an embodiment of the present application, the mass percentage of the aggregate can be 92%, 93%, 94%, 95% or 96%. The present application forms the structural strength of the storage type reactive asphalt mixture after curing by adding aggregate. In the present application, the aggregate does not react, so conventional aggregate can be used. In the embodiments of the present application, the filler can be limestone aggregate and / or basalt aggregate.

[0030] In the present application, the aggregate is preferably dense type grading or intermittent grading. In the present application, the dense type grading is preferably AC-10, AC-13 or AC-16; the intermittent grading is preferably SMA-10 or SMA-13.

[0031] The storage type reaction asphalt mixture provided by the present application comprises a latent alkaline curing agent with a mass percentage of 0.5-5%. As an embodiment of the present application, the mass percentage of the latent alkaline curing agent can be 0.5%, 1%, 2%, 3%, 4% or 5%. In the present application, the latent alkaline curing agent comprises an oxide of alkaline earth metal and / or a hydroxide of alkaline earth metal. In the present application, the oxide of alkaline earth metal comprises calcium oxide and / or magnesium oxide; the hydroxide of alkaline earth metal comprises calcium hydroxide. The present application adopts the latent alkaline curing agent, which has good stability before encountering an activator and can release alkaline substances after encountering the activator.

[0032] The present application further provides a preparation method of the storage type reaction asphalt mixture described in the above technical solution, which comprises the following steps: mixing the asphalt binder, the reaction type viscosity reducer, the inert rheological modifier and the functional additive to obtain a reaction type binder composition; mixing the dried aggregate, the latent alkaline curing agent and the reaction type binder composition to obtain the storage type reaction asphalt mixture.

[0033] In the present application, the method for mixing the asphalt binder, the reaction type viscosity reducer, the inert rheological modifier and the functional additive preferably comprises: preheating the asphalt binder to obtain a preheated asphalt binder; sequentially adding the reaction type viscosity reducer, the inert rheological modifier and the functional additive into the preheated asphalt binder and mixing to obtain the reaction type binder composition.

[0034] In the present application, the preheating temperature is preferably 100-160°C, more preferably 120-150°C. The present application can improve the flowability of the asphalt binder by preheating, thereby facilitating the full dispersion of the reaction type viscosity reducer, the inert rheological modifier and the functional additive in the asphalt binder.

[0035] The present application preferably first performs first stirring after adding the reaction type viscosity reducer and the inert rheological modifier into the preheated asphalt binder, and then performs second stirring after adding the functional additive. In the present application, the rotation speed of the first stirring is preferably 50-500 rpm, more preferably 100-300 rpm; the time of the first stirring is preferably 60-120 min, more preferably 70-100 min. The present application does not have special limitations on the rotation speed and time of the second stirring, and the functional additive can be uniformly dispersed.

[0036] After obtaining the reactive binder composition, the present application mixes the dried aggregate, the latent alkaline curing agent and the reactive binder composition to obtain a storage type reactive asphalt mixture.

[0037] In the present application, the drying method of the aggregate is preferably: heating the aggregate to above 100℃ until completely dried, and then ready for use at a temperature range of 30~100℃.

[0038] In the present application, the mixing method of the dried aggregate, the latent alkaline curing agent and the reactive binder composition is preferably: dry mixing the dried aggregate and the latent alkaline curing agent to obtain a dry mixed material; wet mixing the dry mixed material with the preheated reactive binder composition to obtain a storage type reactive asphalt mixture. In the present application, the dry mixing is the stirring of the dried aggregate and the latent alkaline curing agent under dry conditions; the wet mixing is the stirring of the dry mixed material with the preheated reactive binder composition.

[0039] In the present application, the rotation speed of the dry mixing is preferably 40~120rpm, more preferably 60~100rpm; the time of the dry mixing is preferably 5~30s, more preferably 10~20s. The present application can promote the full mixing of the dried aggregate and the latent alkaline curing agent through dry mixing.

[0040] In the present application, the temperature of the preheated reactive binder composition is preferably 30~100℃, more preferably 50~80℃. The present application uses the preheated reactive binder composition and controls it in the above range, which is more conducive to improving the flowability of the reactive binder composition, and thus is more conducive to the full dispersion of the dry mixed material in the reactive binder composition.

[0041] In the present application, the rotation speed of the wet mixing is preferably 40~130rpm, more preferably 60~120rpm; the time of the wet mixing is preferably 30~90s, more preferably 60~80s. The present application can promote the full dispersion of the dry mixed material in the reactive binder composition through wet mixing.

[0042] The present application preferably seals and stores the storage type reactive asphalt mixture.

[0043] The present application uses the above preparation method, which is more conducive to promoting the uniform mixing of each component and obtaining a storage type reactive asphalt mixture with stable dispersion.

[0044] The present application also provides an evaluation method for the storage life of a storage type reactive asphalt mixture, comprising the following steps: (1) determining the maximum allowable reaction value R limit The asphalt mixture to be tested is stored under the first simulated storage conditions; the asphalt mixture to be tested is the storage-type reactive asphalt mixture described in the above technical solution or the storage-type reactive asphalt mixture prepared by the preparation method of claim 8; Samples were taken out at different storage times, and the following operations were performed on each sample: i) Penetration strength tests were conducted on a portion of the samples to obtain the penetration strength of the samples under different storage times; ii) Dissolve another portion of the sample and then filter to obtain a filtrate; dry the filtrate to obtain recycled binders at different storage times; use Fourier transform infrared spectroscopy to detect the recycled binders at different storage times, and calculate the reaction values ​​of the recycled binders at different storage times according to equation (1): R(t)=[(A(0)-A(t)) / A(0)]×100% Formula (1) In equation (1), R(t) represents the reaction value of the recycled binder at different storage times; A(0) represents the reaction value of the recycled binder at 1730 cm⁻¹ with a storage time of 0. -1 The signal strength at 1730 cm⁻¹; A(t) represents the signal strength of the recycled binder at different storage times. -1 Signal strength at the location; Using the penetration strength of samples at different storage times as the x-axis and the reaction value R(t) of the recycled binder at different storage times as the y-axis, a correspondence between penetration strength and R(t) is established. Based on this correspondence, the R(t) corresponding to the critical penetration strength value is used as the maximum allowable reaction value. R limit ; (2) Monitor changes in reaction values ​​during storage. The asphalt mixture to be tested was stored under the second simulated storage conditions. Samples were taken out at different storage times and the reaction value R(t)' of the samples at different storage times was determined according to the method in step ii). The curve of the reaction value R(t)' changing with time under the second simulated storage conditions was obtained. (3) Predicting storage life By fitting or extrapolating the curve of the reaction value R(t)' under the second simulated storage conditions obtained in step (2) using a mathematical model, the maximum permissible reaction value determined in step (1) is predicted to be reached. R limit The time required for the predicted reaction value to reach the maximum permissible reaction value determined in step (1). R limitThe required time is taken as the predicted storage life of the asphalt mixture under the second simulated storage conditions.

[0045] This invention stores the asphalt mixture to be tested under first simulated storage conditions. In this invention, the first simulated storage conditions are preferably 60~120℃, more preferably 80℃. This invention uses the above temperature range for the first simulated storage, which provides high-temperature accelerated reaction conditions and reduces the time required to determine the maximum permissible reaction value. R limit The time.

[0046] The present invention does not have a specific limitation on the amount of samples taken from the different storage times. The amount of samples taken can meet the requirements of penetration strength testing and Fourier transform infrared spectroscopy analysis for detecting the recycled binder.

[0047] The present invention does not have a specific limitation on the amount of the sample used; the amount can be adjusted to meet the requirements of the penetration strength test.

[0048] This invention does not specifically limit the operation method of the penetration strength test; any conventional penetration strength test method can be used. In this invention, the preferred method for the penetration strength test is JT / T 972-2015.

[0049] The present invention does not have a specific limitation on the amount of the other part of the sample. The amount can be adjusted to meet the requirements of the Fourier transform infrared spectroscopy analysis method for detecting the recycled binder.

[0050] In this invention, the solvent used to dissolve the other portion of the sample is preferably trichloroethylene; the drying method is preferably distillation recovery or rotary evaporation. This invention obtains recycled binders for different storage times through dissolution, filtration, and drying.

[0051] After obtaining the recycled binder under different storage times, the present invention uses Fourier transform infrared spectroscopy to detect the recycled binder under different storage times, and calculates the reaction value of the recycled binder under different storage times according to equation (1): R(t)=[(A(0)-A(t)) / A(0)]×100% Formula (1) This invention does not impose any particular limitation on the Fourier transform infrared spectroscopy analysis method used; conventional Fourier transform infrared spectroscopy analysis methods can be employed. This invention uses Fourier transform infrared spectroscopy analysis to detect recycled adhesives stored for different durations, obtaining infrared spectra of the recycled adhesives at different storage times. Based on these infrared spectra, the infrared spectra of the recycled adhesives at different storage times at 1730 cm⁻¹ are obtained.-1 signal intensity at 1730 cm-1.

[0052] In the present application, in formula (1), R(t) is the reaction value of the recycled binder at different storage times; A(0) is the signal intensity at 1730 cm-1 of the recycled binder with a storage time of 0; A(t) is the signal intensity at 1730 cm-1 of the recycled binder at different storage times; and the signal intensity is preferably the peak area or peak height obtained by Fourier transform infrared spectroscopy. -1 -1

[0053] After obtaining the penetration strength of the sample at different storage times and the reaction value R(t) of the recycled binder at different storage times, the present application establishes a corresponding relationship between the penetration strength and R(t) by taking the penetration strength of the sample at different storage times as the horizontal coordinate and taking the reaction value R(t) of the recycled binder at different storage times as the vertical coordinate; and according to the corresponding relationship between the penetration strength and R(t), the R(t) corresponding to the critical penetration strength value is used as the maximum allowable reaction value. R limit .

[0054] In the present application, the critical penetration strength value is an empirical value. In the embodiments of the present application, the critical penetration strength value can be 5.0 kg / cm2.

[0055] After obtaining the maximum allowable reaction value R limit , the present application stores the asphalt mixture to be tested under a second simulated storage condition, takes out part of the sample at different storage times, and measures the reaction value R(t)' of the sample at different storage times according to the method described in the above technical solution to obtain a regular curve of the reaction value R(t)' changing with time under the second simulated storage condition.

[0056] The evaluation method provided by the present application is intended to evaluate the service life of the mixture under different storage environments, and therefore the second simulated storage condition is not specifically limited and can be adjusted according to the actual storage condition. In the present application, the second simulated storage condition is preferably normal temperature storage.

[0057] After obtaining the regular curve of the reaction value changing with time under the second simulated storage condition, the present application uses a mathematical model to fit or extrapolate the regular curve of the reaction value R(t)' changing with time under the second simulated storage condition described in the above technical solution to predict the time required for the reaction value to reach the maximum allowable reaction value R limit . R limit ​​The required time as the predicted storage life of the asphalt mixture to be tested under the second simulated storage condition.

[0058] The present application uses the change of infrared signal intensity at about 1730 cm -1 representing a carboxyl group to characterize the reaction degree of the asphalt mixture, so that the pre-reaction degree of the material during storage can be simply and reliably quantitatively evaluated, and the remaining effective storage life can be scientifically predicted, thereby providing important technical guidance for production quality control and on-site use, and having important practical significance for production quality control and on-site use.

[0059] The technical solutions in the present application will be clearly and completely described below in combination with the embodiments in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0060] Embodiment 1 A storage type reaction asphalt mixture, components in percentage by mass are: a reaction type binder composition 5.5%, an aggregate (AC-10 graded median limestone) 93.5% and a latent alkaline curing agent (calcium oxide) 1%; The reaction type binder composition includes, in 100 parts by weight of the reaction type binder composition: an asphalt binder (70# asphalt) 69.5 parts, a reaction type viscosity reducer (industrial grade mixed fatty acid) 27 parts, an inert rheological modifier (aromatic oil) 3 parts, and a functional additive (KH-560 coupling agent) 0.5 parts; The preparation method of the storage type reaction asphalt mixture is: The asphalt binder is heated to 120℃ for preheating to obtain a preheated asphalt binder; the reaction type viscosity reducer and the inert rheological modifier are added to the preheated asphalt binder, and first stirring is performed at 300 rpm for 60 min; then the functional additive is added for stirring and mixing to obtain the reaction type binder composition; The aggregate is AC-10 graded median limestone, which is dried by heating to 110℃ and then kept at 80℃ for standby; the dried aggregate and the latent alkaline curing agent are dry mixed at 80 rpm for 15 s to obtain a dry mixed material; the dry mixed material and the reaction type binder composition preheated to 80℃ are wet mixed at 80 rpm for 75 s to obtain the storage type reaction asphalt mixture (referred to as M3), which is then sealed and stored.

[0061] Embodiment 2 A storage type reactive asphalt mixture, components are as follows in percentage by mass: reactive binder composition 5.5%, aggregate (AC-10 graded median limestone) 93.5% and latent alkaline curing agent (calcium oxide) 1%; The reactive binder composition includes: asphalt binder (70# asphalt) 69.5 parts, reactive viscosity reducer (industrial grade mixed fatty acid) 20 parts, inert rheological modifier (aromatic oil) 10 parts, functional additive (KH-560 coupling agent) 0.5 parts, by weight of the reactive binder composition as 100 parts. The preparation method of the storage type reactive asphalt mixture (M4) is the same as that of Example 1.

[0062] Comparative Example 1 A reactive asphalt mixture, components are as follows in percentage by mass: reactive binder composition 5.5%, aggregate (AC-10 graded median limestone) 93.5% and latent alkaline curing agent (calcium oxide) 1%; The reactive binder composition includes: asphalt binder (70# asphalt) 69.5 parts, reactive viscosity reducer (industrial grade mixed fatty acid) 30 parts and functional additive (KH-560 coupling agent) 0.5 parts, by weight of the reactive binder composition as 100 parts. The preparation method of the reactive asphalt mixture is the same as that of Example 1, and the reactive asphalt mixture obtained in this example is referred to as M1.

[0063] Comparative Example 2 A reactive asphalt mixture, components are as follows in percentage by mass: reactive binder composition 5.5%, aggregate (AC-10 graded median limestone) 92.7%, accelerator (polyacrylamide) 0.05%, fiber (polyester fiber with a length of 6mm) 0.25%, curing agent (42.5 ordinary portland cement: kaolin mass ratio is 95:5) 1.5%; The reactive binder composition includes: asphalt binder (70# asphalt) 70 parts, reactive viscosity reducer (mixed by mass ratio of 30:26:40:4 of oleic acid, linoleic acid, linolenic acid and palmitic acid) 30 parts, by weight of the reactive binder composition as 100 parts. The preparation method of the reactive asphalt mixture is the same as that of Example 1, and the reactive asphalt mixture obtained in this example is referred to as M2.

[0064] Example 3 A method for evaluating the storage life of a storage type reactive asphalt mixture: This embodiment aims to demonstrate how to evaluate the storage life of the storage type reaction asphalt mixture (M3) provided in embodiment 1. The method mainly includes two stages of determining the maximum allowable reaction value and predicting the storage life.

[0065] (1) Maximum allowable reaction value R limit determination This step is carried out under the first simulated storage condition to quickly obtain the correspondence between the material performance and the degree of chemical reaction.

[0066] Firstly, the asphalt mixture to be tested prepared in embodiment 1 is placed in a sealed environment at 80℃ for storage. At different storage times (0h, 12h, 24h, 36h, 48h and 60h), part of the sample is taken out respectively, and the following two parallel tests are carried out: i) Physical performance test: take part of the sample, carry out penetration strength test under the condition of 4℃, and record the penetration strength value under different storage times. In this step, the device for penetration strength test is shown in Figure 1 .

[0067] ii) Reaction value R(t) test: take 100g sample, dissolve with trichloroethylene, then filter to obtain filtrate; transfer the filtrate to a rotary evaporation flask, and use a rotary evaporator (as shown in Figure 2 ) to recover the solvent under the condition that the water bath temperature is not more than 90℃ and the vacuum degree is not less than 0.08MPa, to obtain the recovered binder under different storage times. The recovered binder under different storage times is detected by Fourier transform infrared spectroscopy (FTIR) analysis method respectively, to obtain the infrared spectrum of the recovered binder under different storage times, and then the signal intensity of the recovered binder under different storage times at 1730cm -1 is obtained, and then the reaction value R(t) of the recovered binder under different storage times is calculated according to formula (1).

[0068] Through the above test, the data pair of "penetration strength" and "R(t)" of the sample under different storage times is obtained, the penetration strength of the sample under different storage times is taken as the abscissa, and the reaction value R(t) of the recovered binder under different storage times is taken as the ordinate, to establish the correspondence between the penetration strength and R(t); according to the correspondence between the penetration strength and R(t), the reaction value R(t) corresponding to the critical penetration strength value (5.0kg / cm²) is taken as the maximum allowable reaction value R limit .

[0069] In this step, the infrared spectrum of the recovered binder under the storage time of 0h and 24h is shown in Figure 3 .

[0070] (2) Prediction of storage life at room temperature This step is performed under the second simulated storage conditions to predict the actual usable storage period of the material.

[0071] A batch of new asphalt mixture prepared in Example 1 was used as the asphalt mixture to be tested. It was sealed and stored at 25°C. Samples were taken out at different storage times (1 day, 15 days, 30 days, and 60 days). The reaction value R(t)' of the samples at different storage times was determined according to the method in step ii). The curve of the reaction value R(t)' changing with time under sealed storage at 25°C was obtained. Finally, a mathematical model (linear fitting) is used to extrapolate the curve showing the change of the reaction value R(t)' over time under sealed storage at 25°C, predicting that the reaction value will reach the maximum permissible reaction value determined in step (1). R limit The time required for the predicted reaction value to reach the maximum permissible reaction value determined in step (1). R limit The required time is taken as the predicted storage life of the asphalt mixture under the second simulated storage conditions.

[0072] (3) Other performance tests To evaluate the performance of the mixture, another sample of the reactive asphalt mixture provided in Example 1 was used to test its Marshall stability after curing at 25°C for 1 day and 7 days, as well as its dispersion loss rate after 7 days.

[0073] Test Example 1 The reactive asphalt mixtures (M3, M4) provided in Examples 1 and 2 and the reactive asphalt mixtures (M1, M2) provided in Comparative Examples 1 and 2 were tested using the method of Example 3.

[0074] First, under the first simulated storage conditions (80°C), in order to determine the failure criteria for each mixture, i.e., the maximum permissible reaction value. R limit Establish the correspondence between penetration strength and R(t), such as Figure 4 As shown, Figure 5 for Figure 4 A magnified view of a section. Based on workability requirements, 5.0 kg / cm² is set as the critical penetration strength. From... Figures 4-5 As can be seen from the figure, when the penetration strength is 5.0 kg / cm² (see the vertical auxiliary line in the figure), the maximum permissible reaction values ​​corresponding to Comparative Example 1 (M1), Comparative Example 2 (M2), Example 1 (M3), and Example 2 (M4) are as follows: R limitThe percentages were approximately 26.8%, 27.5%, 30.4%, and 31.6%, respectively. This result indicates that M3 and M4, containing the inert rheology modifier of this invention, can tolerate a higher degree of pre-reaction without sacrificing usability and workability compared to M1 and M2.

[0075] Subsequently, under the second simulated storage conditions (25°C), each mixture was stored, and the change in its reaction value R(t) over time was monitored. The results are as follows: Figure 6 As shown in the figure. According to the fitting results, under normal temperature storage conditions, the growth process of the reaction value R(t) of each mixture approximately follows a linear relationship. By comparing the slopes of the fitted lines, the apparent reaction rate (k) of different mixtures during normal temperature storage can be obtained. Specifically, Comparative Example 2 (M2) has the fastest reaction rate (k_M2≈0.0831% / day), followed by Comparative Example 1 (M1) (k_M1≈0.0608% / day). The reaction rates of Examples M3 (k_M3≈0.0459% / day) and M4 (k_M4≈0.0439% / day), which contain the inert rheology modifier of this invention, are significantly lower than the two comparative examples, with M4 having the lowest rate. This demonstrates that the inert rheology modifier of this invention can effectively inhibit the chemical reaction process of the mixture during normal temperature storage, thereby improving storage stability.

[0076] Finally, combining Figure 5 Determined maximum permissible reaction value R limit and Figure 6 The obtained room-temperature reaction rate k can be used to predict the shelf life of each formulation material. Based on the linear growth model, it can be estimated that Comparative Example 1 (M1), Comparative Example 2 (M2), Example 1 (M3), and Example 2 (M4) will reach their respective... R limit The estimated storage lifetimes required for (26.8%), (27.5%), (30.4%), and (31.6%) are approximately 49 days, 32 days, 222 days, and 305 days, respectively. These predictions quantitatively demonstrate that the storage lifetimes of M3 and M4 provided by the embodiments of the present invention far exceed those of the baseline comparative example M1, and are several times greater than those of comparative example M2, highlighting the significant advantages of the present invention in extending storage life.

[0077] Table 1 shows the mechanical property test results of the reactive asphalt mixtures provided in Examples 1-2 and Comparative Examples 1-2, referred to as the mechanical property test results.

[0078] Table 1. Mechanical property test results

[0079] As can be seen from Table 1, the Marshall stability and anti-stripping performance (low flying loss rate) of M1 (containing coupling agent) are both superior to M2. By comparing Examples M3, M4 with the benchmark M1, it is found that the addition of inert rheological modifier, although resulting in a moderate decrease in Marshall stability (M1>M3>M4), confirms a certain trade-off relationship between storage stability and final strength, but it is worth noting that the flying loss rate of M3 and M4 is lower than that of M1, indicating that the anti-stripping performance is not weakened, and even improved. At the same time, the anti-stripping performance of M3 and M4 is also superior to Comparative Example M2.

[0080] As can be seen from the above results, the present application successfully solves the technical problem of poor storage stability of existing reactive asphalt mixture by introducing an inert rheological modifier into the reactive binder, combined with an optimized formulation system, and realizes a significant extension of the storage life. At the same time, the mixture of the present application can still maintain good final mechanical properties and water damage resistance under the condition of a significant extension of the storage period, especially in terms of anti-stripping performance, which is even superior to the benchmark formulation Comparative Example 1 and Comparative Example 2. The evaluation method provided by the present application can also effectively monitor and predict the storage state of the mixture. Therefore, in practical applications, the optimal amount of inert rheological modifier can be selected according to the specific needs of storage time and final performance, so as to obtain a reactive asphalt mixture with long storage period and excellent performance.

[0081] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled persons in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A stored reaction asphalt mixture, characterized in that, comprises, by mass percentage, the following components: a reactive binder composition 4-8%, aggregate 92-96%, and a latent alkaline curing agent 0.5-5%; the reactive binder composition comprises, by weight fraction, the following components: asphalt binder 40-80%, reactive viscosity reducer 15-50%, inert rheological modifier 1-20%, and functional additive 0.1-5%; the reactive viscosity reducer comprises at least one of saturated fatty acid and unsaturated fatty acid; the latent alkaline curing agent comprises oxide of alkaline earth metal and / or hydroxide of alkaline earth metal.

2. The stored reaction asphalt mixture according to claim 1, characterized in that, the asphalt binder comprises at least one of road petroleum asphalt and modified asphalt.

3. The stored reaction asphalt mixture of claim 1, wherein, the reactive viscosity reducer comprises at least one of C8-C24 saturated fatty acid, C8-C24 unsaturated fatty acid, and plant oil foot refining fatty acid.

4. The stored reaction asphalt mixture of claim 1, wherein, the inert rheological modifier comprises at least one of mineral oil, rubber oil, synthetic ester, plant oil, and waste oil refining product.

5. The stored reaction asphalt mixture of claim 1, wherein, the functional additive comprises coupling agent and / or antioxidant.

6. The stored reaction asphalt mixture of claim 1, wherein, the oxide of alkaline earth metal comprises calcium oxide and / or magnesium oxide; the hydroxide of alkaline earth metal comprises calcium hydroxide.

7. The stored reaction asphalt mixture of claim 1, wherein, the aggregate is of dense gradation or intermittent gradation.

8. A preparation method of the storage type reactive asphalt mixture according to any one of claims 1-7, comprising the following steps: mixing the asphalt binder, the reactive viscosity reducer, the inert rheological modifier, and the functional additive to obtain a reactive binder composition; mixing the dried aggregate, the latent alkaline curing agent, and the reactive binder composition to obtain the storage type reactive asphalt mixture.

9. A method of evaluating the storage life of a stored reactive asphalt mixture, characterized by, comprising the following steps: (1) determining a maximum allowable reaction value R limit placing the to-be-tested asphalt mixture under the first simulated storage condition for storage; the to-be-tested asphalt mixture is the storage type reactive asphalt mixture according to any one of claims 1-7 or the storage type reactive asphalt mixture prepared by the preparation method of claim 8; taking out part of the samples at different storage times, respectively, and performing the following operations on each sample: i) performing penetration strength test on part of the samples to obtain the penetration strength of the samples at different storage times; ii) dissolving another part of the samples, then filtering to obtain filtrate; drying the filtrate to obtain recovered binder at different storage times; detecting the recovered binder at different storage times by Fourier transform infrared spectroscopy analysis method, respectively, and calculating the reaction value of the recovered binder at different storage times according to formula (1): R(t) = [(A(0)-A(t)) / A(0)] × 100% formula (1) In formula (1), R(t) is the reaction value of the recycled binder at different storage times; A(0) is the signal intensity at 1730 cm -1 of the recycled binder with a storage time of 0; A(t) is the signal intensity at 1730 cm -1 of the recycled binder at different storage times; establishing the corresponding relationship between penetration strength and R(t) by taking the penetration strength of the samples at different storage times as the abscissa and the reaction value R(t) of the recovered binder at different storage times as the ordinate; According to the correspondence between the penetration strength and R(t), the R(t) corresponding to the critical penetration strength value is used as the maximum allowable reaction value R limit ; (2) monitoring the reaction value change during storage The asphalt mixture to be tested is placed under the second simulated storage condition for storage, and at different storage times, a part of the sample is taken out, the reaction value R(t)' of the sample at different storage times is determined according to the method of step ii), and a regular curve of the change of the reaction value R(t)' with time under the second simulated storage condition is obtained. (3) predicting the storage life fitting or extrapolating the regular curve of the reaction value R(t)' obtained in step (2) under the second simulated storage condition with time, to predict the reaction value reaching the maximum allowable reaction value determined in step (1) R limit the time required for the predicted reaction value to reach the maximum allowable reaction value determined in step (1) R limit the time required as the predicted storage life of the asphalt mixture to be tested under the second simulated storage condition.

10. The method of claim 9, wherein, The temperature of the first simulated storage condition in step (1) is 60-120 DEG C.

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