Detection and analysis method for rapid delineation of aging stages of styrene-butadiene-styrene modified asphalt

Abstract

The present disclosure provides a detection and analysis method for rapid delineation of aging stages of styrene-butadiene-styrene (SBS) modified asphalt, including the following steps: performing a Fourier transform infrared spectroscopy (FTIR) test on unaged SBS-modified asphalt samples to obtain a copolymer index of I.sub.B0/S0 and neat asphalt functional group indexes, including the SI.sub.0, I.sub.B, aI.sub.0, ARI.sub.0, and CI.sub.0; performing the FTIR test on the aged SBS-modified asphalt samples to obtain an actual index of I.sub.B/S, SI, I.sub.B, .sub.aI, ARI, and CI; and delineating three aging stages of SBS-modified asphalt, including a polymer swelling stage, a polymer degradation stage and a component imbalance stage according to changes of functional group indexes. According to the present disclosure, the actual aging stages of the SBS-modified asphalt can be determined rapidly and accurately, providing a reasonable basis for the decision on pavement maintenance timing and mode.

Claims

1. A detection and analysis method for rapid delineation of aging stages of styrene-butadiene-styrene (SBS) modified asphalt, comprising the following steps: (1) performing a Fourier transform infrared spectroscopy (FTIR) test on unaged SBS-modified asphalt samples, detecting the absorbance of infrared spectrum characteristic functional groups polystyrene and polybutadiene of unaged SBS-modified asphalt at 699 cm.sup.1 and 966 cm.sup.1, calculating a value of A.sub.699/A.sub.966, and recording the value as an unaged SBS copolymer index I.sub.B0/S0; and detecting the absorbance of the unaged SBS-modified asphalt at 1030 cm.sup.1, 1456 cm.sup.1, 1600 cm.sup.1, and 1700 cm.sup.1, calculating functional group indexes of sulfoxide group, aliphatic group, aromatic group and carbonyl of the unaged SBS-modified asphalt, and recording the same as indexes of unaged neat asphalt SI.sub.0=A.sub.1030/A.sub.6502000, I.sub.B,aI.sub.0=A.sub.1456/A.sub.6502000, ARI.sub.0=A.sub.1600/A.sub.6502000, and CI.sub.0=A.sub.1700/A.sub.6502000; A.sub.699, A.sub.966, A.sub.1030, A.sub.1456, A.sub.1600, and A.sub.1700 referring to corresponding peak areas at infrared spectrum wave numbers of 699 cm.sup.1, 966 cm.sup.1, 1030 cm.sup.1, 1456 cm.sup.1, 1600 cm.sup.1, and 1700 cm.sup.1, and A.sub.6502000 referring to a sum of peak areas at infrared spectrum wave numbers of 650 cm.sup.12000 cm.sup.1; (2) performing the FTIR test on laboratory-fabricated SBS-modified asphalt samples or in-service SBS-modified asphalt pavement samples; detecting the absorbance of the laboratory-fabricated SBS-modified asphalt or in-service SBS-modified asphalt pavement samples at 699 cm.sup.1 and 966 cm.sup.1, calculating a value of A.sub.699/A.sub.966, and recording the value as an aging SBS copolymer index I.sub.B/S; and detecting the absorbance of the laboratory-fabricated SBS-modified asphalt or in-service SBS-modified asphalt pavement samples at 1030 cm.sup.1, 1456 cm.sup.1, 1600 cm.sup.1, and 1700 cm.sup.1, calculating functional group indexes of sulfoxide group, aliphatic group, aromatic group and carbonyl of the aged SBS-modified asphalt, and recording the same as indexes of aged neat asphalt SI=A.sub.1030/A.sub.6502000, I.sub.B,aI=A.sub.1456/A.sub.6502000, ARI=A.sub.1600/A.sub.6502000, and CI=A.sub.1700/A.sub.6502000; and (3) delineating three aging stages of SBS-modified asphalt according to changes of infrared spectrum characteristic functional group indexes obtained by actual detection and calculation: a, an SBS polymer swelling stage: $0<\frac{I_{B0/S0}}{I_{B/S}}1$ & $0<\frac{\mathrm{SI}}{{\mathrm{SI}}_0}-\frac{I_{B,a}I}{I_{B,a}{I}_0}-\frac{\mathrm{ARI}}{{\mathrm{ARI}}_0}+\frac{\mathrm{CI}}{{\mathrm{CI}}_0}2;$ b, an SBS polymer degradation stage: $\frac{I_{B0/S0}}{I_{B/S}}>1$ & $0<\frac{\mathrm{SI}}{{\mathrm{SI}}_0}-\frac{I_{B,a}I}{I_{B,a}{I}_0}-\frac{\mathrm{ARI}}{{\mathrm{ARI}}_0}+\frac{\mathrm{CI}}{{\mathrm{CI}}_0}2;$ and c, an asphalt component imbalance stage: $\frac{I_{B0/S0}}{I_{B/S}}>1$ & $\frac{\mathrm{SI}}{{\mathrm{SI}}_0}-\frac{I_{B,a}I}{I_{B,a}{I}_0}-\frac{\mathrm{ARI}}{{\mathrm{ARI}}_0}+\frac{\mathrm{CI}}{{\mathrm{CI}}_0}>2.$

2. The detection and analysis method for rapid delineation of aging stages of SBS-modified asphalt according to claim 1, wherein in step (1), liquid samples from unaged SBS-modified asphalt are detected using an FTIR transmission module.

3. The detection and analysis method for rapid delineation of aging stages of SBS-modified asphalt according to claim 1, wherein in step (2), liquid samples from laboratory-fabricated SBS-modified asphalt are detected using the FTIR transmission module.

4. The detection and analysis method for rapid delineation of aging stages of SBS-modified asphalt according to claim 1, wherein in step (2), solid samples from in-service SBS-modified asphalt are detected using an FTIR-Diffuse Reflectance (DR) module.

5. The detection and analysis method for rapid delineation of aging stages of SBS-modified asphalt according to claim 1, wherein a scanning range of infrared spectrum wave number for FTIR test of asphalt samples in step (2) is 400 cm.sup.14000 cm.sup.1, with a total of 32 scans.

6. The detection and analysis method for rapid delineation of aging stages of SBS-modified asphalt according to claim 1, wherein in practical application, according to the three aging stages of SBS-modified asphalt delineated in step (3), the following maintenance measures are implemented for the laboratory-fabricated SBS-modified asphalt and in-service SBS-modified asphalt pavements respectively: a, requiring no maintenance measures in a case that the laboratory-fabricated SBS-modified asphalt pavement or the in-service SBS-modified asphalt pavement is in the SBS polymer swelling stage; b, adding an SBS copolymer linker to the laboratory-fabricated SBS-modified asphalt, and requiring no maintenance measures for the SBS-modified asphalt pavement in a case that the laboratory-fabricated SBS-modified asphalt pavement or the in-service SBS-modified asphalt pavement is in the SBS polymer degradation stage; and c, adding the SBS copolymer linker and neat asphalt rejuvenator to the laboratory-fabricated SBS-modified asphalt, and taking maintenance measures comprising paving micro-overlay, on-site recycling or hot mixing recycling for the SBS-modified asphalt pavement in a case that the laboratory-fabricated SBS-modified asphalt pavement or the in-service SBS-modified asphalt pavement is in the asphalt component imbalance stage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram for calculating the peak area of an absorption peak of Fourier infrared spectrum of asphalt in Example 2;

(2) FIG. 2 is the test result of an infrared spectral absorption peak of unaged SBS-modified asphalt in Example 2;

(3) FIG. 3 is a sample diagram showing sampling from upper and middle layers on in-service SBS-modified asphalt pavement in Example 2; and

(4) FIG. 4 is the test results of the infrared spectrum absorption peak of SBS-modified asphalt with different aging types in Example 2.

DETAILED DESCRIPTION

(5) To make the objectives, technical solutions, and advantages of examples of the present disclosure more precise, the technical solutions in the examples of the present disclosure will be described clearly and completely in the following with reference to the examples of the present disclosure. Obviously, all the described examples are only some, rather than all examples of the present disclosure. On the basis of the examples in the present disclosure, all other examples obtained by those ordinary skilled in the art without creative efforts belong to the protection scope of the present disclosure.

Example 1

(6) Rapid Delineation of the Aging Stages of SBS-Modified Asphalt

(7) (1) FTIR test is performed on unaged SBS-modified asphalt samples by using an FTIR transmission module, the absorbance of infrared spectrum characteristic functional groups polystyrene and polybutadiene of unaged SBS-modified asphalt at 699 cm.sup.1 and 966 cm.sup.1 are detected, and a ratio A.sub.699/A.sub.966 is calculated, which is recorded as an unaged SBS copolymer index I.sub.B0/S0. In the same way, the absorbance of the unaged SBS-modified asphalt at 1030 cm.sup.1, 1456 cm.sup.1, 1600 cm.sup.1, and 1700 cm.sup.1 are detected, and functional group indexes of sulfoxide group, aliphatic group, aromatic group and carbonyl of the unaged SBS-modified asphalt are calculated, which are recorded as unaged neat asphalt indexes SI.sub.0=A.sub.1030/A.sub.6502000, I.sub.B,aI.sub.0=A.sub.1456/A.sub.6502000, ARI.sub.0=A.sub.1600/A.sub.6502000, and CI.sub.0=A.sub.1700/A.sub.6502000.

(8) A699, A966, A1030, A1456, A1600, and A1700 refer to corresponding peak areas at infrared spectrum wave numbers of 699 cm.sup.1, 966 cm.sup.1, 1030 cm.sup.1, 1456 cm.sup.1, 1600 cm.sup.1, and 1700 cm.sup.1, and A6502000 refer to a sum of peak areas at infrared spectrum wave numbers of 650 cm.sup.12000 cm.sup.1.

(9) (2) The FTIR test is performed on laboratory-fabricated SBS-modified asphalt samples or in-service SBS-modified asphalt pavement samples, and the laboratory-fabricated SBS-modified asphalt samples are liquid, which are detected using the FTIR transmission module. An infrared spectrum wave number scanning range of the FTIR test of asphalt samples is 400 cm.sup.14000 cm.sup.1, and scanning times are 32. The in-service SBS-modified asphalt pavement samples are solid and are detected using an FTIR-DR module. The absorbance of the laboratory-fabricated SBS-modified asphalt or the in-service SBS-modified asphalt pavement samples are detected at 699 cm.sup.1 and 966 cm.sup.1, and a value of A.sub.699/A.sub.966 is calculated, which is recorded as an aging SBS copolymer index I.sub.B/S. The absorbance of the laboratory-fabricated SBS-modified asphalt or the in-service SBS-modified asphalt pavement samples is detected at 1030 cm.sup.1, 1456 cm.sup.1, 1600 cm.sup.1, and 1700 cm.sup.1. The functional group indexes of the sulfoxide group, aliphatic group, aromatic group and carbonyl of aged SBS-modified asphalt are calculated, which are recorded as aged neat asphalt indexes SI=A.sub.1030/A.sub.6502000, I.sub.B,aI=A.sub.1456/A.sub.6502000, ARI=A.sub.1600/A.sub.6502000, and CI=A.sub.1700/EA.sub.6502000.

(10) (3) Three aging stages of SBS-modified asphalt are delineated according to changes of infrared spectrum characteristic functional group indexes obtained by actual detection and calculation: a, an SBS polymer swelling stage:

(11) $0<\frac{I_{B0/S0}}{I_{B/S}}1$ &

(12) $0<\frac{\mathrm{SI}}{{\mathrm{SI}}_0}-\frac{I_{B,a}I}{I_{B,a}{I}_0}-\frac{\mathrm{ARI}}{{\mathrm{ARI}}_0}+\frac{\mathrm{CI}}{{\mathrm{CI}}_0}2;$ b, an SBS polymer degradation stage:

(13) $\frac{I_{B0/S0}}{I_{B/S}}>1$ &

(14) 0$0<\frac{\mathrm{SI}}{{\mathrm{SI}}_0}-\frac{I_{B,a}I}{I_{B,a}{I}_0}-\frac{\mathrm{ARI}}{{\mathrm{ARI}}_0}+\frac{\mathrm{CI}}{{\mathrm{CI}}_0}2;$ and c, an asphalt component imbalance stage:

(15) $\frac{I_{B0/S0}}{I_{B/S}}>1$ &

(16) $\frac{\mathrm{SI}}{{\mathrm{SI}}_0}-\frac{I_{B,a}I}{I_{B,a}{I}_0}-\frac{\mathrm{ARI}}{{\mathrm{ARI}}_0}+\frac{\mathrm{CI}}{{\mathrm{CI}}_0}>2.$

(17) (4) In practical application, according to the three stages of the aging stages of SBS-modified asphalt, the following maintenance measures are taken for the laboratory-fabricated SBS-modified asphalt and the in-service SBS-modified asphalt pavement respectively: a, no maintenance measures are to be taken when the laboratory-fabricated SBS-modified asphalt or the in-service SBS-modified asphalt pavement is in the SBS polymer swelling stage; b, an SBS copolymer linker is added to the laboratory-fabricated SBS-modified asphalt, and no maintenance measures are taken for the SBS-modified asphalt pavement when the laboratory-fabricated SBS-modified asphalt or the in-service SBS-modified asphalt pavement is in the SBS polymer degradation stage; and c, the SBS copolymer linker and neat asphalt rejuvenator are added to the laboratory-fabricated SBS-modified asphalt, and maintenance measures including paving micro-overlay, on-site recycling or hot mixing recycling are taken for the SBS-modified asphalt pavement when the laboratory-fabricated SBS-modified asphalt or the in-service SBS-modified asphalt pavement is in the asphalt component imbalance stage.

Example 2

(18) Actual Detection According to the Delineation Method of Example 1 Described Above

(19) 1. Acquisition of Raw Materials

(20) Samples are taken from an SBS-modified asphalt mixing barrel of an asphalt manufacturer in Hubei Province. The samples are taken immediately after the SBS-modified asphalt is prepared, before swelling and development, and recorded as the unaged SBS-modified asphalt.

(21) Samples are taken from an oil unloading tank of an asphalt mixing station in Hubei Province, and the samples are taken immediately when a tank asphalt truck discharges half of the asphalt.

(22) Finally, on the pavement of an expressway in Hubei Province, samples of SBS-modified asphalt in the middle and upper layers with a service life of about 10 years are obtained. When sampling in-service SBS-modified asphalt, surface asphalt is scraped by using a scraper from the upper layer, the middle layer is drilled by using a small core-drilling machine, and scattered asphalt bulk particles are taken. The whole sampling from in-service asphalt pavement is fast and convenient, and basically has no apparent adverse effects on the structural stability of asphalt pavement.

(23) 2. Detection of Raw Materials

(24) After obtaining the above four types of asphalt samples, different FTIR detection modules detect the infrared spectral absorption peaks of asphalt samples according to asphalt forms.

(25) The absorbance of infrared spectrum characteristic functional groups polystyrene and polybutadiene of unaged SBS copolymer at 699 cm.sup.1 and 966 cm.sup.1 are detected by the FTIR transmission module, and a ratio A.sub.699/A.sub.966 is calculated, which is recorded as an unaged SBS copolymer index IBO/so; and the absorbance of infrared spectrum characteristic functional groups of neat asphalt at 1030 cm.sup.1, 1456 cm.sup.1, 1600 cm.sup.1, and 1700 cm.sup.1 are detected, and functional group indexes of sulfoxide group, aromatic group and carbonyl group of unaged neat asphalt are calculated, which are recorded as SI.sub.0=A.sub.1030/A.sub.6502000, I.sub.B,aI.sub.0=A.sub.1456/A.sub.6502000, ARI.sub.0=A.sub.1600/A.sub.6502000, and CI.sub.0=A.sub.1700/A.sub.6502000. The calculation results are shown in Table 1 below.

(26) TABLE-US-00001 TABLE 1 Calculation results of functional group indexes of unaged SBS-modified asphalt Types of asphalt I.sub.B0/S0 SI.sub.0 I.sub.B,aI.sub.0 ARI.sub.0 CI.sub.0 Unaged SBS-modified asphalt 0.75 0.05 0.25 0.14 0.03

(27) An FTIR test is performed on laboratory-fabricated SBS-modified asphalt or in-service SBS-modified asphalt pavement samples, the laboratory-fabricated SBS-modified asphalt samples are detected by the FTIR transmission module, and the in-service SBS-modified asphalt samples are detected by an FTIR-DR module. The absorbance of the laboratory-fabricated SBS-modified asphalt or the in-service SBS-modified asphalt pavement samples at 699 cm.sup.1 and 966 cm.sup.1 are calculated, and a ratio A.sub.699/A.sub.966 is calculated, which is recorded as an aging SBS copolymer index I.sub.B/S. The absorbance at 1030 cm.sup.1, 1456 cm.sup.1, 1600 cm.sup.1, and 1700 cm.sup.1 are calculated, and the functional group indexes of sulfoxide group, aromatic group, and carbonyl of aging neat asphalt are calculated, which are recorded as SI.sub.0=A.sub.1030/A.sub.6502000, I.sub.B,aI=A.sub.1456/A.sub.6502000, ARI=A.sub.1600/A.sub.6502000, and CI=A.sub.1700/A.sub.6502000. The calculation results are shown in Table 2 below.

(28) TABLE-US-00002 TABLE 2 Calculation results of functional group indexes of laboratory-fabricated SBS-modified asphalt and in-service SBS-modified asphalt Types of asphalt I.sub.B/S SI I.sub.B,aI ARI CI Laboratory-fabricated SBS-modified 0.72 0.06 0.23 0.14 0.03 asphalt SBS-modified asphalt in the upper 0.48 0.11 0.15 0.09 0.08 layer SBS-modified asphalt in the middle 0.62 0.07 0.19 0.12 0.06 layer

(29) According to the detected functional group indexes of the laboratory-fabricated SBS-modified asphalt and the in-service SBS-modified asphalt, the aging stages of SBS-modified asphalt is delineated into three stages, as shown in Table 3 below.

(30) TABLE-US-00003 TABLE 3 Aging stages of laboratory-fabricated SBS-modified asphalt and in-service SBS-modified asphalt Types of asphalt $\frac{I_{B0/S0}}{I_{B/S}}$ $\frac{SI}{S{I}_0}-\frac{I_{B,a}I}{I_{B,a}{I}_0}-\frac{ARI}{AR{I}_0}+\frac{CI}{C{I}_0}$ Aging stages Laboratory-fabricated 1.04 0.28 SBS polymer degradation SBS-modified asphalt stage SBS-modified asphalt in the upper 1.63 3.62 Asphalt component layer imbalance stage SBS-modified asphalt in the 1.21 1.78 SBS polymer degradation middle layer stage

(31) According to the above detection results, an appropriate amount of SBS copolymer linker will be added to the laboratory-fabricated SBS-modified asphalt. It is suggested that the in-service asphalt pavement to be covered with micro-overlay to prolong the service life of the pavement and improve the service level of the pavement.

(32) It is to be noted that relational terms, relational terms including first and second, and the like, may be used herein to distinguish one entity or orientation from another entity or orientation without necessarily requiring or implying any actual such relationship or order between the entities or orientations. Furthermore, the terms including, comprising, or any other variations thereof are intended to cover non-exclusive inclusion so that a process, method, article, or apparatus including a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of more restrictions, an element defined by the phrase including a . . . does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

(33) The above examples are only used to illustrate the technical solutions of the present disclosure, rather than limiting the present disclosure. Although the present disclosure has been described in detail concerning the foregoing examples, those ordinary skilled in the art will understand that the technical solutions disclosed in the above examples can still be modified, or equivalents can replace some of the technical features. These modifications and substitutions do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of various examples of the present disclosure.