Workability and rheological properties of EVA-modified bitumen compared with PG 76 binder

The failures of the flexible pavements are not only caused by harsh climatic conditions prevailing in most of the tropical countries but also due to increase in traffic. The ethylene vinyl acetate (EVA) modification of the bitumen can strengthen the properties of binders and also improve the quality of bitumen used for pavements construction. This paper reports the changes in physical and rheological properties of unaged 80-100 grade bitumen modified with different percentages of EVA and compared with the properties of PG 76 binder. The penetration, softening point and viscosity properties were studied. The rheological properties were measured using dynamic shear rheometer and the test was performed at temperatures ranging from 46 to 76 ⁰C at intervals of 6 ⁰C. It was noted that, after modification, the properties of binders had improved. The results show that 5% EVA content by weight in modified binder is adequate in terms of physical and rheological properties studied. In addition, the properties of 5% EVA modified 80-100 grade bitumen are similar to PG 76 binder

Evaluation of vehicle overloading along Muar-Melaka road

Vehicle overloading is considered as one of the most substantial concerns in road transport due to a possible road surface damage. This paper investigates the vehicle overloading at the Muar-Malacca roads. The main objectives for this study were to determine types of vehicles overloaded, the percentage of overloaded vehicles and an average equivalency (EF) for all vehicles. Secondary data were collected from fixed weighbridge station by considering gross vehicle weight, maximum permissible gross vehicle and axle load for the period of two years. The results show that heavy vehicle with 2 axles was the most overloaded vehicle. Category 1% -25% overloaded vehicles had the highest percentage. The calculated EF was 3.14 higher than standard EF. Thus, the road needs to redesigned in order to resist current load to prevent road damage in short term

Evaluation of skid resistance performance using british pendulum and grip tester

A good road surface texture is very important to minimize road accident due to skidding problem. Many tools are used to measure skid resistance of road surface such as British Pendulum and Grip Tester. British Pendulum can be classified as traditional tool while Grip Tester is an advanced equipment. British Pendulum Number (BPN) and Grip Number (GN) are the output values from the respective tools. The main objective of this study was to establish relationship between BPN and GN. The tests were conducted on Asphaltic Concrete Wearing Course (ACW20) road surface located at selected Expressway in Selangor and State Road in Melaka. The results show a very weak correlation between both tests where the regression value was less than 0.19. It is recommended that further investigation and more tests on different types of surface be conducted to improve the correlation between the BPN and GN

Relationship between rutting, roughness and resilient modulus of flexible expressway pavement

The study was conducted to investigate the relationship between rutting, roughness and resilient modulus of flexible expressway pavement. The evaluation was conducted at Shah Alam Expressway from km 17.90 to km 52.20. The expressway consisted of three lanes for each bound (slow, middle and fast lanes). The scanner vehicle was used to evaluate the roughness and rutting of the entire test section and the roughness value was given in the International Roughness Index (IRI). While, the resilient modulus values for bituminous layer (E1), road base (E2) and subgrade (E3) were determined by Falling Weight Deflectometer (FWD). IRI and rutting values show that the expressway was in a good to satisfactory condition. In term of resilient modulus, most of the E1 and E2 layers were in the sound to satisfactory condition except 20.1% and 32.1% of the slow lane section was in poor condition, respectively. Resilient modulus of E3 for the entire section was in the sound to satisfactory condition. As a conclusion, the fast lane shows a better condition compares to the middle and slow lanes. In addition, poor correlation was found between rutting, roughness and resilient modulus respectively

Application of alternative filler in asphalt mixture: An overview from Indonesia perspective

A good quality and proper quantity of filler material is one of the significant factors in producing asphalt mixture. Many studies have been highlighted waste material as an alternative filler to improve asphalt mixture performance. Hence, this paper reviewed the performance of asphalt mixture using rice husk ash (RHA) as filler in terms of the Marshall properties. It shows that 6% RHA by weight of total aggregate was commonly used and depicted better in Marshall properties than the others. This study also found that the RHA can be used to replace up to 100% of the conventional filler. Even though, higher RHA content could significantly reduce the stability yet it still within the acceptable range and could be applied at medium traffic load road. In return, the higher the RHA content the more waste material can be utilized for road construction. Thus, minimized the usage natural source materials

Investigation on road damage due to vehicle overloading of high volume Ipoh state road

Traffic load was a major factor in thickness design due to the main function of pavement which was to resist traffic load. Although efforts to repair the road damage had been done continuously, the recovering effects were almost meaningless if the road was continuously receiving overloading from vehicles. Issues of road damage due to vehicle overloading had been addressed by most agencies in developing countries. However, there were no available study to address this issue on Perak state road. Therefore, this research aimed to determine the current traffic composition, the percentage of overloading vehicle, the Equivalence Factor (E.F.), the adequacy of existing pavement thickness and the reduction of pavement service life due to overloading of the road by referred to AASHTO and Arahan Teknik (Jalan) 5/85. The selected study area was at Jalan Tuanku Abdul Rahman, Ipoh (also known as Jalan Kuala Kangsar). Data were employed which acquired from traffic count survey, axle load survey, coring test and dynamic cone penetrometer test. Review on current traffic count data showed that vehicles with 2-axle contributes more than 60% of the overall daily traffic while percentage of overloading vehicle revealed that more than 50% of vehicles contributed from 4-axle, 5-axle and 6-axle exceeded the maximum permissible gross vehicle weight (PGVW). The analysis on the E.F. showed that primary and secondary directions gained E.F. value of 4 and 3 times higher than the 3.0 E.F. design value which were 12.4 and 9.2 respectively. This also denoted that additional overlay pavement thickness was required about 70mm and 50mm for primary and secondary direction respectively to ensure the target design life was achieved. This study also discovered the road pavement experienced 7 and 6 years of reduction of service life for both directions respectively

Performance evaluation of asphalt micro surfacing - A review

In spite the fact that micro surfacing receives accolades by researchers of being the most cost-effective, environmentally friendly, and functionally viable pavement preventive maintenance amongst the various asphalt surface treatments (AST). However, there has not been a universally standardised mix design, acceptable material type, compatible polymer-binder combination, laboratory-field correlational performance tests, and its field dependency performance indicators. The requirements set by the International Slurry Surfacing Association (ISSA), Malaysian Jabatan Kerja Raya (JKR-public works department) and American Society for Testing and Materials (ASTM) are stated to be guides. This study brings to fore the challenges, methodologies adopted and successes recorded towards solving the aforementioned concerns by various researches globally from existing literatures with emphasis on material-type effects, mix design methodology, serviceability/environmental performance, incorporation of industrial wastes and emulsion-polymer compatibility amongst others in micro surfacing. Hence, the contents of relevant published journal articles, theses, academic and industrial reports published within the last two decades (1979 - 2019) that met the selection criteria aforementioned were critiqued. Result indicated improvement in key pavement surface functional performance parameters as a function of enhanced polymer(s) used in improving desired performance, type of aggregate and its gradation, pre-treatment condition and ultimately emulsion type. However, there is a lack of total consensus on the mix design, even though polymers are unanimously agreed by researchers to improve performance. Future advances in micro surfacing should focus on the use of industrial wastes, synthetic material and especially by-products from industrial processes

Rejuvenation of hot mix asphalt incorporating high RAP content: Issues to consider

The asphalt used to construct or rehabilitation roads often contains reclaimed asphalt pavement (RAP) in order to diminish not only the use of raw materials but also waste. However, when high level of RAP in hot mix asphalt (HMA) is used, the rejuvenating agents must be employed. A number of aspects must be taken into account to increase pavement service life as much as possible. Thus, the main issues related to the rejuvenation of asphalt mixtures with high levels of RAP are addressed in this paper. In particular, the focal points of this paper will focus on the use of reclaimed asphalt mixtures with maximum efficiency, special attention is paid to how the binder is structured and chemically composes, nature and dose selection of rejuvenator, as well as the diffusion, blending efficiency, homogeneity, time and temperature mixing. A review of the extant and related literature shows that RAP utilization holds promise for the sustainable pavements, provided that some issues were taken into consideration during the designing and application process

Drivers behaviour on expressways: headway and speed relationships

This paper describes result of a study on driver's car following behaviour on Malaysian high-speed highways. Drivers' car following behaviour can considered as one of the main factors that causes road accidents to occur such as rear end collision between vehicles on highways. The aim of the study was to examine the safe following distance adopted by drivers on expressways at various operating speeds. An automatic traffic recording device attached with pneumatic tubes was used to record traffic movement at three selected expressway segments in Malaysia for six consecutive days. More than one hundred thirty three thousand (133,000) headway and speed data were involved in the analysis. The distance headway and associated speed collected were classified into five vehicle following categories by vehicle type, i.e. all vehicles, car following car, car following heavy goods vehicle (HGV), HGV following HGV, and HGV following car. Linear regression models were used to develop relationship between distance headway and speed. The relationships developed can be regarded as reliable since the R2-values for each of the relationships is in the range of 0.80 to 0.99 and can be used to estimate a safe following distance perceived by a driver at a given speed. The driver's average response time on an expressway is 3.06 sec which is 1.9 sec longer than those who are driving on a two-lane single-carriageway road. Such a variation in response time indicates that the level of aggressiveness of drivers on a two-lane single-carriageway road are higher than the drivers on an expressway

Repeatability of reclaimed asphalt pavement as related to properties of bitumen

Material recycling is one of the best solution that support sustainability aspect and at the same time reduce the construction and material cost. One of the common method in bituminous recycling is using reclaimed asphalt pavement (RAP). Although usage of RAP in the pavement has been established, properties of bitumen after repeated recycling process is unclear. Bitumen was extracted from recommended recycled mixtures that had undergone through repeated recycling process. In this study, bitumen was assessed in three different ageing stages namely 0 Cycle, 1st Cycle and 2nd Cycle. 0 Cycle is the sample which extracted from fresh mixture (represents 100% fresh materials). 1st and 2nd Cycles represent the number of recycling process. Penetration, softening point and viscosity test were used to evaluate the properties of extracted bitumen. From the tests, the results indicate that repeated recycling process generally increased hardness of the bitumen. This result was proven with the reduction in penetration value and increased in softening point temperature. Furthermore, it was also discovered that multiple recycling stages reduced the mixture workability, which was demonstrated by the increment of viscosity value. Hence, recycling process without any rejuvenator is applicable up to certain levels only