scholarly journals Cold In-Place Recycling Asphalt Mixtures: Laboratory Performance and Preliminary M-E Design Analysis

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2036
Author(s):  
Dongzhao Jin ◽  
Dongdong Ge ◽  
Siyu Chen ◽  
Tiankai Che ◽  
Hongfu Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Dynamic Modulus ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Emulsion ◽  
Moisture Susceptibility ◽  
Low Temperature Cracking

Cold in-place recycling (CIR) asphalt mixtures are an attractive eco-friendly method for rehabilitating asphalt pavement. However, the on-site CIR asphalt mixture generally has a high air void because of the moisture content during construction, and the moisture susceptibility is vital for estimating the road service life. Therefore, the main purpose of this research is to characterize the effect of moisture on the high-temperature and low-temperature performance of a CIR asphalt mixture to predict CIR pavement distress based on a mechanistic–empirical (M-E) pavement design. Moisture conditioning was simulated by the moisture-induced stress tester (MIST). The moisture susceptibility performance of the CIR asphalt mixture (pre-mist and post-mist) was estimated by a dynamic modulus test and a disk-shaped compact tension (DCT) test. In addition, the standard solvent extraction test was used to obtain the reclaimed asphalt pavement (RAP) and CIR asphalt. Asphalt binder performance, including higher temperature and medium temperature performance, was evaluated by dynamic shear rheometer (DSR) equipment and low-temperature properties were estimated by the asphalt binder cracking device (ABCD). Then the predicted pavement distresses were estimated based on the pavement M-E design method. The experimental results revealed that (1) DCT and dynamic modulus tests are sensitive to moisture conditioning. The dynamic modulus decreased by 13% to 43% at various temperatures and frequencies, and the low-temperature cracking energy decreased by 20%. (2) RAP asphalt incorporated with asphalt emulsion decreased the high-temperature rutting resistance but improved the low-temperature anti-cracking and the fatigue life. The M-E design results showed that the RAP incorporated with asphalt emulsion reduced the international roughness index (IRI) and AC bottom-up fatigue predictions, while increasing the total rutting and AC rutting predictions. The moisture damage in the CIR pavement layer also did not significantly affect the predicted distress with low traffic volume. In summary, the implementation of CIR technology in the project improved low-temperature cracking and fatigue performance in the asphalt pavement. Meanwhile, the moisture damage of the CIR asphalt mixture accelerated high-temperature rutting and low-temperature cracking, but it may be acceptable when used for low-volume roads.

scholarly journals How the Mix Factors Affect the Dynamic Modulus of Hot-Mix Asphalt

2019 ◽  
Vol 3 (3) ◽  
pp. 72
Author(s):  
Md Rashadul Islam ◽  
Sylvester A. Kalevela ◽  
Guy Mendel
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Dynamic Modulus ◽  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Performance Grade ◽  
Reduced Frequency ◽  
Nominal Size ◽  
S 100

Hot-mix asphalt (HMA) is a composite material consisting of stone-aggregates, sand, asphalt binder and additives. The properties of this combined material are dependent on the volumetric parameters used in the mix design. This study investigates the effects of volumetric mix factors on the dynamic moduli (E*) of eleven categories of HMAs. For each category of asphalt mixture, the variations in dynamic modulus for different contractors, binder types, effective binder content (Vbe), air void (Va), voids-in-mineral aggregates (VMA), voids-filled-with asphalt (VFA) and asphalt content (AC) are assessed statistically. Results show that the S(100) mixture (nominal size of 19 mm, 100 gyrations) with the Performance Grade (PG) binder of PG 64-22 has the highest value of E* at low temperature or high reduced frequency. At high temperature or lower reduced frequency, S(100) PG 76-28 has the highest E* value. The SX(75) mixture (nominal size of 12.5 mm, 75 gyrations) with the binder of PG 64-28 has the lowest E* value at high temperature or lower reduced frequency. At low temperature or high reduced frequency, SX(75) PG 58-34 has the lowest E* value. The Stone Mix Asphalt (SMA) mix has a lower E* compared to S(100) and SX(100) mixes ((nominal size of 12.5 mm, 100 gyrations) with the Performance Grade (PG) binder of) at low temperature. The E* increases with an increase in Vbe, Va, and VFA, and decreases with an increase in VMA and AC. The E* of a mix can vary from 200 ksi (1380 MPa) to about 1000 ksi (6900 MPa) for a particular frequency (10 Hz) and temperature (21.1 °C), even if samples are from the same contractor.

scholarly journals A Study on the Application of Rock Asphalt from Sichuan China Based on Anti-Rutting Performance

2019 ◽  
Vol 9 (5) ◽  
pp. 870 ◽  
Author(s):  
Limin Li ◽  
Zhaoyi He ◽  
Weidong Liu ◽  
Cheng Hu
Keyword(s):  
Low Temperature ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Strength Ratio ◽  
Modified Asphalt ◽  
Freeze Thaw ◽  
Splitting Strength ◽  
Tensile Fatigue

To solve the early rutting failure of asphalt pavement, the application of rock asphalt from Sichuan, China, based on anti-rutting performance, was studied. Preparations of North Sichuan rock asphalt (NS RA) and NS RA-modified asphalt mixture were elaborated in detail. Using Zhonghai AH-70 asphalt, Esso AH-70 asphalt, North American rock asphalt (NA RA) and NS RA, the performances of NS RA modified asphalt were researched based on index tests, Brookfield rotary viscosity test and bending beam rheometer test. A performance verification of NS RA-modified asphalt was carried out using rutting calculation, the rutting, indirect tensile fatigue, freeze–thaw split and small beam bending tests based on five kinds of selected gradations. The results indicated that in comparison with NA RA, the NS RA has a good modification effect as well. The NS RA can obviously improve the anti-rutting ability of the asphalt binder, and it can enhance its anti-aging performance as well. For the NS RA-modified asphalt mixture, it is feasible to determine the optimum NS RA content, based on its anti-rutting performance, and its optimum NS RA content is about 8%. The dynamic stability values of NS RA-modified asphalt mixtures are at least 3-fold higher than those of the base asphalt mixtures, and they are all far greater than the summer hot area requirement (no less than 2800 times/mm). NS RA-modified asphalt mixtures used in the middle course of asphalt pavement can obviously improve the anti-rutting performance of the pavement, and to enhance the anti-rutting ability of pavements, it should be used in the middle course of the pavement. The fatigue life values of NS RA-modified asphalt mixtures are at least 14.5-fold higher than those of the base asphalt mixtures. The freeze–thaw splitting strength ratio values of NS RA-modified asphalt mixtures are improved by at least 9.5% over the base asphalt mixtures, and their freeze–thaw splitting strength ratio values are all greater than the requirement (no less than 75%). In comparison with the base asphalt, the low temperature performances of NS RA-modified asphalt and its mixtures slightly decline, but they can meet the requirements for the zones with a minimum temperature of no less than –21.5 °C too. Therefore, except for the extremely low temperature area, it is an effective method for solving the rutting problem of pavement for using NS RA-modified asphalt.

scholarly journals Evaluating the Effect of Plastomer Modified Asphalt Mixture on High/Low Temperature Performance

2021 ◽  
Vol 40 (3) ◽  
pp. 680-691
Author(s):  
Rafi Ullah ◽  
Imran Hafeez ◽  
Waqas Haroon ◽  
Safeer Haider
Keyword(s):  
Low Temperature ◽  
Dynamic Modulus ◽  
Research Study ◽  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Limestone Aggregate ◽  
Temperature Performance ◽  
Low Temperature Performance

Asphalt pavement’s surfaces deteriorate over time due to combined effect of traffic and surrounding environment. Fatigue and rutting are the major distresses which cause failures in flexible pavements. Different temperature control computer operated equipment’s are being used worldwide to predict the performance of asphalt mixtures at approximately same condition to those in-service pavements. Similarly, different types of polymers such as elastomer and thermoplastic have been used all over the world in Hot Mix Asphalt (HMA) for the improvement of asphalt mixtures. But little attention has been taken to evaluate the effect of plastomer on hot mix asphalt performance. Moreover, the initial cost of elastomer is higher than other types of polymers such as plastomer. The aim of this research study is to check the effect of various plastomers on high/low temperature performance of asphalt mixture. Four performance tests like Cooper wheel tracker, dynamic modulus, uniaxial repeated load and four-point bending beam test are used to evaluate the effect of different type of plastomers such as polyethylene terephthalate, high density and low density polyethylene with limestone aggregate quarry and 60/70 pen grade asphalt binder. This research study concludes that plastomer increases flexibility and hardness of asphalt mixtures and improves the rut resistance, dynamic modulus and fatigue life of asphalt mixtures. Plastomer modification shows significant benefits as compared to neat binder for high/low temperature performance. Moreover, it can be concluded that plastomer provides an efficient and economical blend of asphalt mixture.

scholarly journals Investigation of the Road Performance of AH-30 Bitumen and Its Mixture: Comparison with AH-70 and SBS-Modified Bitumen

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chenfeng Chu ◽  
Jing Zhu ◽  
Zi-ang Wang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Fatigue Property ◽  
Asphalt Mixtures ◽  
The Road ◽  
Road Performance ◽  
Better Than ◽  
Temperature Crack

AH-30 is a type of high-viscosity matrix asphalt. The asphalt mixture made by AH-30 as a binder has an excellent antirutting performance. However, the other road performance of AH-30 was still worthy of attention. This research aims to reveal the properties of AH-30 and its impact on the road performance of asphalt mixtures (AH30-AC20/25). The AH-70 neat asphalt and SBS modified asphalt were prepared for comparison. The high-temperature sensitivity and fatigue resistance of AH-30 are evaluated by the dynamic shear rheological (DSR) test. The low-temperature performance is evaluated by the bending beam rheometer (BBR) test. The high-temperature stability (HTS) of AH30-AC20/25 is carried out by the wheel tracking (WT) test and the repeated shear constant height (RSCH) test. The low-temperature crack resistance (LTCR) is carried out by the direct stretching (DS) test. The fatigue property is carried out by the three-point bending test. Water stability (WS) is carried out by the Marshall residual stability (MRS) and the intensity ratio of the frozen and melted (IRFM) test. The test results show that the high-temperature resistance of AH-30 is better than that of AH-70. The low-temperature crack resistance of AH-30 is equivalent to that of AH-70. The AH-30 as a binder can meet the requirements of the roads, which are located at a minimum temperature of not less than −10.5°C in winter. The fatigue property of the AH-30 asphalt mixture is poor, which may be one reason why AH-30 asphalt pavement is more prone to cracking. The water stability of the AH30-AC (20/25) asphalt mixture can meet the specification requirements, and AH30-AC20 is better than the other two asphalt mixtures. The research of this paper will provide a basis and reference for the popularization and application of AH-30 in asphalt pavement.

scholarly journals Performance and Microstructure of Cold Recycled Mixes Using Asphalt Emulsion with Different Contents of Cement

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2548 ◽  
Author(s):  
Yanhai Yang ◽  
Ye Yang ◽  
Baitong Qian
Keyword(s):  
Low Temperature ◽  
Temperature Stability ◽  
Hydration Products ◽  
High Temperature Stability ◽  
Asphalt Emulsion ◽  
Moisture Susceptibility ◽  
Pavement Maintenance ◽  
Maintenance And Rehabilitation ◽  
Low Temperature Cracking ◽  
Temperature Crack

Cold recycled mixes using asphalt emulsion (CRME) is an economical and environmentally-friendly technology for asphalt pavement maintenance and rehabilitation. In order to determine the optimum range of cement contents, the complex interaction between cement and asphalt emulsion and the effects of cement on performance of CRME were investigated with different contents of cement. The microstructure and chemical composition of the fracture surface of CRME with different contents of cement were analyzed in this paper as well. Results show that the high-temperature stability and moisture susceptibility of CRME increased with the contents of cement increasing. The low-temperature crack resistance ability gradually increased when the content of cement is increased from 0% to 1.5%. However, it gradually decreased when the content of cement is increased from 1.5% to 4%. Cold recycled mixes had better low-temperature cracking resistance when the contents of cement were in the range from 1% to 2%. The results of microstructure and energy spectrum analysis show that the composite structure is formed by hydration products and asphalt emulsion. The study will be significant to better know the effects of cement and promote the development of CRME.

Determining Optimum Carbon Nanotubes Content for Asphalt Mixture in Road Pavements

2021 ◽  
Vol 1023 ◽  
pp. 121-126
Author(s):  
Van Bach Le ◽  
Van Phuc Le
Keyword(s):  
Carbon Nanotubes ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Construction Cost ◽  
Asphalt Mixtures ◽  
Static Modulus ◽  
Pavement Construction ◽  
Modified Binder ◽  
Marshall Stability

Although small amount of binder in asphalt concrete mixture may commonly range from 3.5 to 5.5% of total mixture as per many international specifications, it has a significant impact on the total cost of pavement construction. Therefore, this paper investigated the effects of five carbon nanotubes contents of 0.05%, 0.1%, 0.15%, 0.2%, 0.25% by asphalt weight as an additive material for binder on performance characteristics of asphalt mixtures. Performance properties of CNTs modified asphalt mixtures were investigated through the Marshall stability (MS) test, indirect tensile (IDT) test, static modulus (SM) test, wheel tracking (WT) test. The results indicated that asphalt mixtures with CNT modified binder can improve both the rutting performance, IDT strength and marshall stability of tested asphalt mixtures significantly at higher percentages of carbon nanotubes. However, the issue that should be considered is the construction cost of asphalt pavement. Based on the asphalt pavement structural analysis and construction cost, it can be concluded that an optimum CNT content of 0.1% by asphalt weight may be used as additive for asphalt binder in asphalt mixtures.

Effectiveness of Loaded Wheel Tracking Test to Ascertain Moisture Susceptibility of Asphalt Mixtures

2021 ◽  
pp. 036119812110363
Author(s):  
Moses Akentuna ◽  
Louay N. Mohammad ◽  
Sanchit Sachdeva ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Creep Recovery ◽  
Moisture Susceptibility ◽  
Freeze Thaw ◽  
Wheel Tracking ◽  
Mixture Samples

Moisture damage of asphalt mixtures is a major distress affecting the durability of asphalt pavements. The loaded wheel tracking (LWT) test is gaining popularity in determining moisture damage because of its ability to relate laboratory performance to field performance. However, the accuracy of LWT’s “pass/fail” criteria for screening mixtures is limited. The objective of this study was to evaluate the capability of the LWT test to identify moisture susceptibility of asphalt mixtures with different moisture conditioning protocols. Seven 12.5 mm asphalt mixtures with two asphalt binder types (unmodified PG 67-22 and modified PG 70-22), and three aggregate types (limestone, crushed gravel, and a semi-crushed gravel) were utilized. Asphalt binder and mixture samples were subjected to five conditioning levels, namely, a control; single freeze–thaw-; triple freeze–thaw-; MiST 3500 cycles; and MiST 7000 cycles. Frequency sweep at multiple temperatures and frequencies, and multiple stress creep recovery tests were performed to evaluate asphalt binders. LWT test was used to evaluate the asphalt mixture samples. Freeze–thaw and MiST conditioning resulted in an increase in stiffness in the asphalt binders as compared with the control. Further, freeze–thaw and MiST conditioning resulted in an increase in rut depth compared with the control asphalt mixture. The conditioning protocols evaluated were effective in exposing moisture-sensitive mixtures, which initially showed compliance with Louisiana asphalt mixture design specifications.

Effect of Anti-Rut Agents on Properties of Asphalt Mixture

2014 ◽  
Vol 599 ◽  
pp. 110-114 ◽  
Author(s):  
Yan Hua Wang ◽  
Kuang Yi Liu ◽  
Hai Xia Zhang ◽  
Shan Li
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Low Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Damage Resistance ◽  
Damage Stability ◽  
Low Temperature Cracking ◽  
Water Damage

Anti-rut agent, named RPS-3000,was added into AC-25 asphalt mixture and its effects on high temperature stability, low temperature cracking resistance, water damage resistance and fatigue life were investigated in this paper. Results showed that the high temperature stability and low temperature crack resistance of the asphalt mixture improved significantly, the water damage stability increase slightly due to the introduction of anti-rut agents. Besides, the result of fatigue life test presented that excess amount of anti-rut agent may lead a deterioration of fatigue life. Keywords: Anti-rut agent; High temperature stability; Asphalt mixture

Influence of Double-Doped Admixtures on Asphalt Mixture Performance

2012 ◽  
Vol 557-559 ◽  
pp. 329-333
Author(s):  
Zhong Run Zheng ◽  
Chao Zhao ◽  
Yi Feng Zhao ◽  
Pei Song
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Rutting Resistance ◽  
Splitting Test ◽  
Improvement Effect ◽  
Low Temperature Cracking ◽  
Better Than

This paper introduces an asphalt mixture that mixed with different admixtures, rutting resistance agent and lignin fiber, at the same time. Rutting test and freeze-thaw splitting test are used to analyze rutting resistance on the high temperature and low temperature cracking of the asphalt mixture. The experiments with different mixes material composition are conducted to analysis various properties of the two admixtures on the mixture, especially the high temperature stability, low temperature crack resistance and the law of improvement effect. In addition, the experiments also determine the optimal asphalt content of different type of mixtures. The results showed that the single-doped KTL rutting resistance or lignin fibers have some improvement in water temperature performance of asphalt mixture, stability improvement of double-doped admixture asphalt mixture is better than the single-doped asphalt mixture, such as KTL rutting resistance agents and lignin fibers

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