scholarly journals The Effect of UV Irradiation on the Chemical Structure, Mechanical and Self-Healing Properties of Asphalt Mixture

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2424 ◽  
Author(s):  
Shaopeng Wu ◽  
Yong Ye ◽  
Yuanyuan Li ◽  
Chuangmin Li ◽  
Wei Song ◽  
...  

Although huge numbers of investigations have been conducted for the ultraviolet (UV) aging of asphalt binder, research rarely focuses on the asphalt mixture. In order to evaluate the aging effect of UV radiation on the asphalt mixture, a dense grade of asphalt mixture was designated and aged by UV radiation for 7, 14 and 28 days respectively. After that, the chemical functional groups of asphalt binder were tested by Fourier transform infrared spectrometer (FTIR). The semi-circular bending strength and fatigue resistance of asphalt concrete were tested to characterize the mechanical properties of the asphalt concrete. To evaluate the self-healing effect of the macro-structure continuity of asphalt concrete intuitively, the computed tomography (CT) scanning machine was used to characterize the crack size of asphalt concrete samples both before and after self-healing. The results show that, with the increase of UV irradiation time, the relative ratios of the C=O and S=O bands’ areas of recovered asphalt binder increase significantly. UV radiation can significantly weaken the mechanical and self-healing properties of asphalt mixture, making the asphalt mixture to have worse macro-structure continuity, lower failure strength and worse fatigue resistance. Moreover, the longer the UV irradiation time is, the degradation effect of UV radiation on asphalt mixture becomes more obvious.

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5277
Author(s):  
Shiqi Wang ◽  
Huanyun Zhou ◽  
Xianhua Chen ◽  
Minghui Gong ◽  
Jinxiang Hong ◽  
...  

Semi-flexible pavement (SFP) is widely used in recent years because of its good rutting resistance, but it is easy to crack under traffic loads. A large number of studies are aimed at improving its crack resistance. However, the understanding of its fatigue resistance and fatigue-cracking mechanism is limited. Therefore, the semi-circular bending (SCB) fatigue test is used to evaluate the fatigue resistance of the SFP mixture. SCB fatigue tests under different temperature values and stress ratio were used to characterize the fatigue life of the SFP mixture, and its laboratory fatigue prediction model was established. The distribution of various phases of the SFP mixture in the fracture surface was analyzed by digital image processing technology, and its fatigue cracking mechanism was analyzed. The results show that the SFP mixture has better fatigue resistance under low temperature and low stress ratio, while its fatigue resistance under other environmental and load conditions is worse than that of asphalt mixture. The main reason for the poor fatigue resistance of the SFP mixture is the poor deformation capacity and low strength of grouting materials. Furthermore, the performance difference between grouting material and the asphalt binder is large, which leads to the difference of fatigue cracking mechanism of the SFP mixture under different conditions. Under the fatigue load, the weak position of the SFP mixture at a low temperature is asphalt binder and its interface with other materials, while at medium and high temperatures, the weak position of the SFP mixture is inside the grouting material. The research provides a basis for the calculation of the service life of the SFP structure, provides a reference for the improvement direction of the SFP mixture composition and internal structure.


2021 ◽  
Vol 45 (1) ◽  
pp. 11-15
Author(s):  
Arabi N.S. Al Qadi ◽  
Taisir S. Khedaywi ◽  
Madhar A. Haddad ◽  
Owies A. Al-Rababa'ah

Technology in transportation used available resources to make it safe, fast, suitable, easy, economic, and environmental to transport people and goods. Olive Husk became an environmental problem as waste materials especially in the Middle East where huge quantities are found. The objective of this research is to investigate the effect of addition of Olive Husk Ash (OHA) on the properties of asphalt concrete mixtures. Marshall Test was used to perform the asphalt concrete mixture by the addition of OHA to the binder of asphalt; different percentages of OHA (0, 5, 10, 15, and 20%) by volume were added to the binder. Five percent of asphalt cements (5, 5.5, 6, 6.5 and 7%) by weight and limestone aggregate were used for preparing asphalt mixture specimens to find the optimum content of asphalt that could be used in the binder. Tests on flow, stability, air void percentage and void in mineral aggregate, retained stability, stiffness, and retained stiffness were made. The principle results on OHA as filler in Asphalt binder improves the Marshall Stability, and void in mineral aggregate and decrease in flow, retained stability, stiffness, and retained stiffness with a 10%-15% of olive husk ash replacement of asphalt binder. The contribution that OHA could be used as a pavement construction material in field.


2019 ◽  
Vol 9 (4) ◽  
pp. 628 ◽  
Author(s):  
Lívia Garcia-Gil ◽  
Rodrigo Miró ◽  
Félix Pérez-Jiménez

Thin asphalt concrete overlays are a maintenance technique that mainly restore the functional properties of pavements. One of the main issues in thin overlays is reflective cracking that can cause early deterioration and reduce their service life. For this reason, the purpose of this investigation is to evaluate the effect of material selection on cracking performance of asphalt concrete mixtures for thin overlays. In particular, this paper evaluates the role of aggregate skeleton gradation. The study of the effect of aggregate gradation was divided into two stages: (1) fine fraction content and (2) maximum nominal aggregate size. Based on this, up to seven asphalt mixture gradations were designed and evaluated through the Fénix test at different test temperatures. The results showed a significant correlation between the fine fraction content, and maximum nominal aggregate size, and the cracking performance of the asphalt concrete mixtures. Mixtures manufactured with a low content of fine aggregates, as well as small nominal maximum size, experienced a further improvement of their toughness. These results reflected the importance of considering not only the effect of asphalt binder and environmental conditions but also aggregate gradation in the design of asphalt concrete mixtures in order to achieve a desirable cracking performance.


2012 ◽  
Vol 204-208 ◽  
pp. 3852-3858 ◽  
Author(s):  
Li Qiang Luan ◽  
Xiao Ge Tian

Repeated loading will produce cumulative damage to asphalt concrete, because of the visco-elastic property of asphalt concrete, a certain degree of self-healing may occurred in case the loads being taken away.( the healing effect is more obvious under higher temperature or pressure),this process can be indicated through adding the intermittent time factor to fatigue test of asphalt concrete .This study adds intermittent time factor to asphalt concrete fatigue testing through universal testing machine,, deeply analyzing the effect of intermittent time, confirming that 0.5 second intermittent time is a key time point to fatigue process ,fatigue rate under 15 °C is slower than that under 20 °C,and introducing the effect factor to the fatigue equation.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1266
Author(s):  
Wentong Huang ◽  
Xiao Liu ◽  
Shaowei Zhang ◽  
Yu Zheng ◽  
Qile Ding ◽  
...  

The construction of sponge city is a major green innovation to implement the concept of sustainable development. In this study, the road performance of permeable asphalt concrete (PAC), which displays pronounced water permeability and noise reduction that are favorable for sponge cities, has been improved with a two-fold modification using styrene–butadiene–styrene (SBS) and crumb rubber (CR). Four percent SBS and three different ratios (10%, 15%, and 20%) of CR have been used to modify the virgin asphalt binder. The Marshall design has been followed to produce PAC samples. To evaluate the asphalt binder performance, multiple-stress creep-recovery (MSCR) test, linear amplitude sweep (LAS) test, and engineering property test programs including softening point test, penetration test, and rotational viscosity test have been conducted. Freeze–thaw splitting test, Hamburg wheel-tracking test, resilient modulus test, and permeability coefficient test have been performed to evaluate the asphalt mixture performance. The test results show that the addition of SBS and CR reduces the permeability coefficient, but significantly improves the high temperature performance, fatigue performance, and rutting resistance as well as the resilient modulus. However, the optimum rubber content should not exceed 15%. Meanwhile, after adding CR and SBS modifier, the indirect tensile strength (ITS) and tensile strength ratio (TSR) increase. It indicates that the moisture stability and crack resistance have been improved by the composite modification effect.


2019 ◽  
Vol 2 (2) ◽  
pp. 214
Author(s):  
Faisal Abdul Yusuf ◽  
Ahmad Ridwan ◽  
Yosef Cahyo Setianto Poernomo

Asphalt Concrete (Hotmix) is a mixture of coarse aggregate, fine aggregate, and filler (filler) with asphalt binder in high-temperature conditions (heat) with a composition that is examined and regulated by technical specifications. In this research, concrete asphalt mixture was added with dolomite powder as a  mixture in filler to be an alternative material for portland cement filler mixture to minimize the price of portal and cement, which is increasingly expensive, and brantas sand as fine aggregate to study and determine the effect of dolomite powder and brantas sand in the mixture asphalt concrete with the addition of levels of 5%, 10%, and 15%. From the results of the study obtained the value of adding dolomite powder with levels of 5%, 10%, 15% at VIM values of 11.99%, 15.28%, 10.29 , VMA value of 26.30%, 29.05%,  24.88%,  VFB  value  of  54.49%,  48.33%,  58.81%,  stability  value  of  3402.503  kg, 3294.030 kg, 1958.946 kg, MQ value 733,8130 kg, 456,1891 kg, 471,9089 kg and from the testing chart the optimum content is at levels 5.5% to 8% and the maximum level is at 5% level.Aspal  Beton  (Hotmix)  adalah  campuran  agregat  kasar,  agregat  halus,  dan  bahan pengisi (Filler) dengan bahan pengikat aspal dalam kondisi suhu tinggi (panas) dengan komposisi yang diteliti dan diatur oleh spesifikasi teknis. Pada penelitian ini, campuran aspal beton diberi bahan tambahan serbuk dolomite sebagai campuran pada filler agar menjadi bahan alternativ campuran filler semen portaland untuk meminimalisir harga semen portaland yang  semakin  mahal  dan  pasir  brantas  sebagai  agregat  halus  untuk  mempelajari  dan mengetahui pengaruh serbuk dolomit dan pasir brantas pada campuran aspal beton dengan penambahan kadar 5%, 10%, dan 15%.dari hasil penelitian didapat nilai penambahan serbuk dolomite dengan kadar  5%, 10%, 15% pada nilai VIM sebesar 11,99%, 15,28%, 10,29, nilai VMA 26,30%, 29,05%, 24,88%, nilai VFB 54,49%, 48,33%, 58,81%, nilai stabilitas 3402,503 kg, 3294,030 kg, 1958,946 kg, nilai MQ 733,8130 kg, 456,1891 kg, 471,9089 kg dan dari grafik pengujian kadar optimum pada kadar 5,5% sampai 8% dan kadar maximum pada kadar 5%.


2019 ◽  
Vol 5 (9) ◽  
pp. 2058-2069 ◽  
Author(s):  
Rana Khaled Hamdan ◽  
Saad Issa Sarsam

Recycling can be considered as one of the measures of sustainable methods. The physical traits of the asphalt mixture under the influence of accelerated aging (Long and Short–Term) for asphalt concrete were assessed. Asphalt cement (40-50), aggregate with 12.5 mm nominal extreme size and limestone dust as filler of the mineral was used for the preparation of asphalt concrete mixture. At the optimum content of the asphalt and asphalt of 0.5 percent below and above the optimum value, specimens were prepared by using Marshall Method. Two types of polymers as recycling agents were used (Polyethylene of Low Density and Crumb Rubber) with (0.5, 1 and 1.5) % by weight of the binder. The indirect tensile test was used for the mixtures at 25 ºC and double punch test at 60 ºC. It was determined that the use of (asphalt binder mixed with rubber) as the agent of recycling showed improved performance than the other kind of recycling agent. The indirect tensile strength at 40 ˚C of the recycled mixture was higher than that the control mixture. Punching shear strength was decreased by 84 %, temperature susceptibility was decreased by 69.6 % and the resistance to moisture damage increases by3.3 % at optimum asphalt content.


2021 ◽  
Vol 27 (2) ◽  
pp. 59-72
Author(s):  
Zahraa Ahmed Samor ◽  
Saad Issa Sarsam

Laboratory experience in Iraq with cold asphalt concrete mixtures is very limited. The design and use of cold mixed asphalt concrete had no technical requirements. In this study, two asphalt concrete mixtures used for the base course were prepared in the laboratory using conventional cold-mixing techniques to test cold asphalt mixture (CAM) against aging and moisture susceptibility. Cold asphalt mixtures specimens have been prepared in the lab with cutback and emulsion binders, different fillers, and curing times. Based on the Marshal test result, the cutback proportion was selected with the filler, also based on the Marshal test emulsion. The first mixture was medium setting cationic emulsion (MSCE) as a binder, hydrated lime, and ordinary portland cement as a filler (7.95% MSCE + 2%HL + 3% OPC). The second mixture used was medium curing cutback (MC-250) as a binder and ordinary portland cement as a filler (5.18% MC 250 + 5% OPC). The indirect tensile strength (ITS) of the samples was measured at 25 ° C. It was found that the cold mix with the MSCE binder had a high ITS value relative to the cold mix with the cutback asphalt binder (MC-250). The dry mixture of MSCE  ITS was approximately 3.77 times the dry mixture of MC-250. The MSCE wet mix was about 4.2 times the wet MC-250 mix. Tensile strength ratio result (TSR %) for the MSCE binder mix and the cutback MC-250 binder mix showed that the MSCE mix has a reasonable moisture resistance (77% ) compared to the MC-250 mix (69.2 %). The aging test and aging ratio result showed that asphalt binder oxidation has a significant effect on age-related pavement degradation as it changes the time-temperature relationship depending on the viscoelastic properties of the asphalt binder. The result clearly showed that the MSCE binder mix had a high resistance to aging (440 Kpa) compared to the cutback (MC-250) binder mix (110 Kpa). In contrast, the MSCE aging ratio (90 %) was higher than the MC-250 ratio (85 %).


2011 ◽  
Vol 467-469 ◽  
pp. 1541-1545 ◽  
Author(s):  
Tian Gui Liu ◽  
Shao Peng Wu ◽  
Jun Han

Montmorillonite(MMT)is a typical layered silicate. It has been widely used to modify polymers. It improves the thermal, mechanical and aging properties of polymers. The prominent features of MMT modified asphalt concrete are significant for prolonging the service life of asphalt pavement. The profound researches on the service performance and mechanical characteristics of MMT modified asphalt binder and mixtures are important for the application of MMT modified asphalt concrete in practice projects. The effect of MMT on the creep properties of asphalt mixture has been investigated in the research. The result showed that the physical capabilities of MMT modified bitumen was improved evidently. UTM 25 electro-hydraulic servo-universal testing machine was used to do Creep Text, and proper rheological models are employed to describe such characteristics. Results indicated that the visco-elastic properties of the mixtures can be changed by the use of MMT. The revised Burgers model is suitable for the visco-elastic property research of MMT modified asphalt mixtures. The model demonstrated that the retardant visco-elastic property and viscous property of asphalt mixtures containing MMT can be improved, which result in the enhancement of resistance to permanent deformation for MMT modified asphalt mixtures.


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