AASHTO Method Research Articles

Optimalisasi Biaya Dan Waktu Terhadap Perencanaan Jalan Dengan Menggunakan Metode Bina Marga 1987 Dengan Berbagai Tebal Indek Perkerasan (Studi Kasus : Pada Ruas Jalan Puruk Cahu - Km 50 - Batas Kota Muara Teweh Kabupaten Barito Utara)

Pavement planning is good, because in this way the pavement construction is able to carry the load of vehicles passing on it and spread the load to the layers beneath it, including the subgrade, without causing significant damage to the road construction itself. The purpose of this study is to obtain the most efficient alternative pavement thickness index and to obtain the required cost and time. The results showed that the Pavement Thickness Index (ITP) using the Bina Marga Method = 7.48 and the 1993 AASHTO Method = 10.20 had a difference of 2.72. The difference in Pavement Thickness Index (ITP) resulted in the addition of pavement thickness using the 1993 AASHTO Method. The economical Pavement Thickness Index (ITP) was the ITP Bina Marga Method with a construction cost of Rp 12.7 billion, with savings of Rp 3.8 billion. By determining the pavement thickness at the same base layer = 20 cm, it is found that the type of material is Aggregate Class B, CBR is 80% cheaper than cement + CTRB with savings of Rp 913,991,544, - ~ 1 billion. The time required in implementing the Bina Marga Method is more efficient than the 1993 AASHTO Method with a savings of 44 days, this is due to cement work + CTRB = 15 + 29 = 44 days. While Aggregate Class B, CBR 80% only takes 22 days, thus saving 22 is also due to the larger ITP of the 1993 AASHTO Method so that it requires additional thickness of the base layer under Aggregate Class C, CBR 30% of 22 cm thus increasing the duration of the implementation time by 24 days

Effects of recycling agents (RAs) on rutting resistance and moisture susceptibility of mixtures with high RAP/RAS content

Increasing the content of Recycled Asphalt Materials (RAM) in Hot Mix Asphalt (HMA) requires a comprehensive understanding of the effects of RAM on pavement performance. While there is a significant focus on the benefits of adding the Recycling Agents (RAs) in terms of cracking resistance of high RAM mixtures, limited research is published on the rutting and moisture damage of high RAM mixtures containing significant amounts of Recycling Agents. This study investigates the effects of RAs on the rutting resistance and moisture susceptibility of high RAM mixtures through analysis of analyzing the Hamburg Wheel-Track Test (HWTT) data with current AASHTO method and a modified analysis method separating the dry from the wet behavior. The RAM employed in this study includes Reclaimed Asphalt Pavements (RAP) and Recycled Asphalt Shingles (RAS). Two levels of high RAP mixtures (30% and 50%) and one combination of RAP and RAS (30% + 5%) were used to fabricate test asphalt mixtures and compared to a control mixture with no RAM. One petroleum-based RA (REOB) and two bio-based RAs were used to soften these mixtures using pre-determined dosages. In total thirteen-three mixture combinations were prepared and measured in this study. The HWTT test parameters recommended in the current AASHTO method were calculated and compared with the parameters determined by using a modified analysis method, in which the deformation due to the visco-plastic flow is separated from the deformation induced by moisture in the wet HWTT. The results illustrate that in general high RAM improved the rutting resistance and moisture susceptibility as compared to the virgin mixture, but some of the RAs used, show an alarming increase in the moisture susceptibility potential of the high RAM mixtures. It is therefore concluded that caution should be used in analysis of the HWTT rutting behavior of high RAM mixes as the RA used could result in inferior rutting behavior under wet conditions.

Design of NH-10 and NH-73 Byircmethod and their comparison with Aashto Method and Pcamethod

Nowadays, Environment Sustainability and effective use of natural resources is a great concern. To build hundreds of kilometres of roadway it involves huge amount of natural resources and we know that our natural resources are in very limited quantity. To save our limited resources any sustainable approach or any green technology or any method that can let us use our resources effectively is welcomed. One such approach for the sustainability of the environment is presented in this paper through the different pavement design approaches. In recent years, cement concrete pavements are being adopted in many new road projects in India in view of their longer service lives, lesser maintenance requirements and smoother riding surface. In this paper, National Highway-10 (Hisar and Dabwali) and National Highway-73 (Punchkula and Yamunanagar) is designed by three methods i.e. by IRC Method which is followed in India and by AASHTO method and PCA Method which are used in American countries. As the IRC method is partly based on the recommendations of AASHTO method and PCA method, it is required to compare the methods to know which is having more economical approach. Through this paper it is found that the IRC gives relatively less thickness as compared to other methods. By this finding we can say that in IRC method the quantity of materials required such as aggregate, bitumen etc.is less which in turn saves our natural resources and preserves our resources for future use. It is also found that the IRC method is more economical.

Perencanaan Perkerasan Kaku (Rigid Pavement) Dengan Menggunakan Wiremesh Pada Ruas Jalan HOS. Cokroaminoto Dan Jalan Moch. Yamin (Tuban)

Highway is one of the land transportation infrastructure which plays an important role in human life in the field of transportation. Jalan Hos. Cokroaminoto and Jalan Moch. Yamin is a national road that fights important to support the economic flow of the surrounding region and also other cities.The author will compare the calculations using two methods, namely the Bina Marga Method 2002 and the AASHTO 1993 method in order to obtain the value of pavement, besides that it also wants to see which method is more efficient and economical in terms of pavement thickness and cost.From the results of the road pavement planning used, the thickness of the pavement is according to the planned 20-year age from 2017 to the end of the year plan for 2037. Economic factors also taken into account in this analysis include the 1993 AASHTO Method.The input parameters of pavement thickness planning for the 1993 AASHTO method are traffic parameters, subgrade reaction modulus, pavement construction material, reliability, and drainage coefficient. For the Jalan Hos section. Cokroaminoto and Jalan Moch. Yamin concrete plate thickness based on the calculation of the 2002 Bina Marga method is 20 cm, while based on the 1993 AASHTO method it is 29 cm. The difference obtained is quite large, namely 9 cm. This is due to differences in the input parameters of each method. Based on the survey that has been done, the thickness of the existing concrete slab is 29 cm, the thickness is the same as the results of calculations using the AASHTO 1993 method.

Escape Hill as Geotechnical Quick Response Method in Facing Upcoming Tsunami Disaster

High number of casualties due to Aceh’s Tsunami in 26th December 2004 was because of lack of information regarding to the disaster among Aceh government and people at that time. Escape building as a quick response for tsunami disaster may become an inevitable action in shoreline of Banda Aceh in facing forthcoming disaster. Moreover, as a result of open space need due to environmentally friendly infrastructure campaign nowadays, the construction of green design of escape hill can be considered. Escape hill can also be functionalized as recreation zone like green park. This article study purpose is to design an escape hill with the rule of geotechnical engineering aspect namely bearing capacity of soil below the escape hill and slope soil stability for the designing escape hill. Deah Baro Village of Meuraxa district was chosen as an escape hill design location. Several undisturbed soil samples were taken within this village for obtaining the existing soil parameters. There were eight hills modelling have been conducted by using Plaxis software. Based on the slope stability result from Plaxis software and by using natural soil as subgrade with soil classification of A-1-b as AASHTO method, the settlement value of final model dimension was 9.117 cm with safety factor of 1.507. The safety factor is still acceptable because of still larger that 1.5 as a standard value for slope safety factor. Escape hill geometry dimension is 12 m high which is larger than tsunami run up wave with soil pressure was calculate per layers of 2 m.

Glulam timber bridges for local roads

Glued-laminated (glulam) and cross-laminated timbers are gaining interests in bridge engineering community due to their improved strength and enhanced durability compared to sawn lumber. The main bridge type on South Dakota local roads is a precast prestressed double-tee girder bridge, which has only one supplier in the state. In an attempt to provide more bridge type selection options for local governments, the system performance of two types of glulam timber bridges was investigated through full-scale experiments. One glulam girder bridge and one glulam slab bridge were tested under fatigue and strength loading. Both bridge types showed minimal damage during the fatigue testing and the bridge stiffness remained constant. Strength testing of the two bridge systems confirmed that the AASHTO method of design for timber bridges is adequate. Girders of glulam girder bridges should be designed as fully non-composite members. A cost analysis showed that the superstructure cost of glulam timber bridges can be 30–50% lower than the precast prestressed double-tee bridge superstructure cost. Based on the construction, testing, and cost analysis, it is concluded that both types of glulam timber bridges are viable alternatives to precast prestressed double-tee bridges to be used on local roads.

Pavement Structural Capacity from Traffic Speed Deflectometer for Network Level Pavement Management System Application

Structural number (SN) represents the structural capacity of a flexible pavement system to sustain anticipated traffic and is among the structural indices most commonly used by pavement design engineers in the U.S. Effective structural number (SNeff) is an indicator of structural capacity of in-service pavement sections and is conventionally estimated from nondestructive testing (NDT) device data such as falling weight deflectometers (FWDs) using methods such as suggested by AASHTO. In addition to pavement design, structural condition is a critical input for the selection of maintenance and rehabilitation strategies in pavement management system (PMS) application. However, use of SN in network level application has not been practical because of limitations of FWD such as stop-and-go operation, lane closures, and low testing frequency. The traffic speed deflectometer (TSD), a continuous deflection device, has recently been gaining worldwide application as a reliable NDT device for network level PMS applications. The objective of this study is to develop a practical approach to compute and utilize SN of in-service flexible pavements from TSD data for network level PMS applications. The study is based on the fundamental that, for the same pavement, SNeff from the TSD using the proposed method should be in good agreement with SNeff from the FWD using AASHTO method. The developed method was field validated with TSD and FWD data collected at in-service pavement sections. In addition, the use of structural number ratio, defined as a ratio of SNeff to required SN, in network level prioritization of structural capacity improvements was illustrated.

The effect of axle load spectra from AASHTO method on flexible pavement performance

Currently, methods used for pavement design are empirical and based on experiments conducted in the 1960s. Due to the number of variables that can influence an empirical analysis, the National Cooperative Highway Research Program (NCHRP) proposed a mechanistic-empirical method. Based on this method, the MEPDG (Mechanistic-Empirical Pavement Design Guide) software was developed and later, its improved version, the AASHTO Ware Pavement ME Design. In both software versions, default values were developed from traffic data of the United States. However, characteristics of the Brazilian traffic are different from characteristics in the United States. Therefore, this study aimed to verify the effect on national pavement performance due to the use of the default axle load spectra that are available on both software versions. Thus, computer simulations were performed using Brazilian axle load spectra, based on data collected at the Imigrantes Highway in Sao Paulo, and using the default load spectra of the software. The results show that the Brazilian axle load spectra studied damages more the national pavement than the default spectra of the software. Therefore, it is not recommended the use of default spectra for designing Brazilian highways similar to the one studied, because this would lead to under-designed structures.

Investigating laboratory parameters of the resistance of different mixtures of soil – lime – fume using the curing and administrative method

Soils treatment is affected by various factors such as density, moisture content and mineral composition of soil and different percentages of materials in soil. Lime soil as a suitable and inexpensive material has been used for decades to stabilize in civil engineering projects; however, the effect of adding fume and curing temperature on strength and stability parameters of the mixture seldom been studied. In this study, soil and water has been studied from Dokhtar Borji in Hosseinieh city in Iran. Based on a laboratory study, we dealt with evaluating the physical and mechanical properties of soils and chemical properties of soil and water. The cylindrical samples of different mixtures of soil- lime- fume were modified using the AASHTO method and compressive strength testing of 7-, 14- and 28-day samples were conducted according to ASTM standards at 27°C. Analysis was conducted in SAS (Statistical Analysis System) software. Results indicated that the increase in average compressive strength from 7 to 14 and from 14 to 28days were 62 and 53.57%, respectively. Therefore, by increasing the number of curing days from 7 to 14, the percentage of the compressive strength is at its highest. The study also provided a linear regression equation that determines compressive strength with an accuracy of 95.1%.

Investigating different approaches for evaluation of fatigue performance of warm mix asphalt mixtures

Fatigue is one of two major performance issues in flexible pavements that caused by repeated traffic loading. There are several methods for determination of fatigue life like 50% stiffness reduction (AASHTO), energy-based methods, and fracture mechanics. The primary objective of this study is exploring the effect of choosing different methods to determine the fatigue life of warm mix asphalt (WMA) in comparison with hot mix asphalt (HMA). WMA mixtures were prepared using Aspha-min and Sasobit additives. Four-point flexural beam test was employed according to AASHTO T321 to evaluate fatigue performance of WMA and HMA mixtures. The tests were conducted at four strain levels 650, 800, 1000, and 1200 (more than typical strain levels) and two frequencies of 7.5 and 15 Hz at 20 °C. The fatigue life of asphalt mixes determined using three different approaches including AASHTO, Rowe and Bouldin (R&B), and rate of dissipated energy changes (RDEC). In addition, a fatigue damage analysis using linear (Ecole Nationale des Travaux Publics de l’Etat) ENTPE model was performed to compare damage evolution of WMA and HMA mixtures in given loading conditions. AASHTO method was a more sensitive approach for evaluating effects of loading conditions on fatigue life of WMA mixtures. Based on the AASHTO method results, the fatigue life of WMA mixtures at 15 Hz was lower than HMA. In practical strain levels and at 7.5 Hz, WMA was more fatigue resistant than HMA. The fatigue lives estimated using both of the energy methods (R&B and RDEC) were approximately same. They predict fatigue lives of WMA mixtures about five times of standard AASHTO method, specifically using RDEC method. In addition, damage analysis method justifies that the AASHTO is not a reliable approach for fatigue life prediction and the energy methods are better approaches.

Evaluating Annual Average Daily Traffic Calculation Methods with Continuous Truck Traffic Data

Traffic volume, often measured in relation to annual average daily traffic (AADT), is a fundamental output of traffic monitoring programs. At continuous count sites, unusual events or counter malfunctions periodically cause data loss, which influences AADT accuracy and precision. This paper evaluates five methods used to calculate AADT values from continuous count data, including the use of a simple average, the commonly adopted method developed by AASHTO (the AASHTO method), and methods that incorporate adjustments to the AASHTO method. The evaluation imposes data removal scenarios designed to simulate real-life causes of data loss to quantify the accuracy and precision improvements provided by these adjustments. Truck traffic data are used to reveal issues arising when volumes are low or when they exhibit unusual temporal patterns. Unlike the AASHTO method, which incorporates a weighted average and an hourly base time period, the FHWA method provides the most accurate and precise results in all data removal scenarios, according to the evaluation. Specifically, when up to 15 days of data are randomly removed, application of the FHWA method can be expected to produce errors within approximately é1.4% of the true AADT value, 95% of the time. Results also demonstrate that including a weighted average improves AADT accuracy primarily, whereas the use of hourly rather than daily count data influences precision. If possible, practitioners contemplating the adoption of the FHWA method should assess its relative advantages within their local context.

Study of the Visco-Elastic Parameters of Asphalt Concrete

The asphalt mixture as the basic construction material in roads is described with specific deformation parameters. These are negatively influenced by temperature, and this is one of the problems which cause short pavement lifespan. Increasing temperature affects the behavior of bitumen-bonded materials from elastic to viscous state. Observation of this problem was made in this study by measuring the phase angle during dynamic bending tests. Temperature dependence of the phase angle was observed for three different temperatures and five chosen frequencies. Another aim of the study was to observe the relationship of the phase angle to the fatigue lifespan for one specific temperature and frequency. The evaluation was done using the classical AASHTO method as well as the chosen dissipated energy ratio method.

Using Eurocodes and Aashto for assessing shear in slab bridges

Reinforced concrete short-span solid-slab bridges are used to compare Dutch and North American practices. As an assessment of existing solid-slab bridges in the Netherlands showed that the shear capacity is often governing, this paper provides a comparison between Aashto (American Association of State Highway and Transportation Officials) practice and a method based on the Eurocodes, and recommendations from experimental research for the shear capacity of slab bridges under live loads. The results from recent slab shear experiments conducted at Delft University of Technology indicate that slabs benefit from transverse force redistribution. For ten selected cases of straight solid-slab bridges, unity checks (the ratio between the design value of the applied shear force and the design beam shear resistance) are calculated according to the Eurocode-based method and the Aashto method. The results show similar design shear forces but higher shear resistances in the North American practice, which is not surprising as the associated reliability index for Aashto is lower.

Reliability and construction control of vibro piles

Abstract The goal of this study was to determine the most reliable and efficient combination of design and construction methods required for vibro piles. For a wide range of static and dynamic formulas, the reliability-based resistance factors were calculated using EGYPT database, which houses load test results for 318 piles. The analysis was extended to introduce a construction control factor that determines the variation between the pile nominal capacities calculated using static versus dynamic formulae. From the major outcomes, the lowest coefficient of variation is associated with Davisson’s criterion, and the resistance factors calculated for the AASHTO method are relatively high compared with other methods. Additionally, the CPT-Nottingham and Schmertmann method provided the most economic design. Recommendations related to a pile construction control factor were also presented, and it was found that utilizing the factor can significantly reduce variations between calculated and actual capacities.

Toward a Better Estimation of Annual Average Daily Bicycle Traffic: Comparison of Methods for Calculating Daily Adjustment Factors

Several methods exist to calculate and apply adjustment factors for bicycle traffic. The reported accuracy of these factors differs from one study to another, making it difficult for transportation professionals to decide which method is preferable. The objective of this study is to compare the estimation accuracy of methods used to calculate daily adjustment factors and to quantify the performance of these methods relative to their mathematical intensity. Three methods of calculating daily adjustment factors were studied: the AASHTO method, the monthly and weather-specific method, and the day-of-year method. The estimation accuracy of annual average daily bicycle traffic volumes was assessed. The results supported the superiority of day-of-year factors, for which the mean absolute percent error (MAPE) was about 17.5%. Second was the monthly and weather-specific factors (MAPE ≈ 24.5%), and third was the AASHTO factors (MAPE ≈ 30.0%). Detailed error analysis was carried out to select the best days for bicycle volume data collection. The daily factor was modeled against day-specific attributes, such as weather conditions and day type, in an attempt to compute generic factors that are applicable to other locations. The model showed very good fit to the data with a coefficient of determination of about .87. The model was further used to develop daily factors for the validation data set and hence calculate annual average daily bicycle volumes. The MAPE was found to be 26.4% for all days and 20.5% for weekday data. The paper provides insights on the advantages and disadvantages of each calculation method and shows the priority preference of application.

Design of Geogrids for Road Base Stabilization

Geogrids are extensively used for the stabilization of paved and unpaved road bases on soft soils. The design methods presently available for use of geogrids in road base stabilization provide no or insufficient information about the required number of layers and the mechanical characteristics of geogrids. Hence, a new design method has been developed which includes the design of geogrids for road base stabilization, based on a 4 layer model: asphalt (binder and wearing course), base, subbase and subgrade. The base and/or subbase thickness has to be defined with one of the available methods such as AASHTO method, Giroud–Han method, Leng–Gabr method, etc. The proposed design method can be used to calculate the tensile forces in the geogrids generated by: self weight of the different layers; wheel load of heavy vehicles; membrane effect at the base (or subbase)–subgrade interface. It is then possible to set the number and the mechanical characteristics of geogrid layers required for absorbing the horizontal forces generated by these three mechanisms.

The Problem Of Imputation Of The Missing Data From The Continuous Counts Of Road Traffic

AbstractMissing traffic data is an important issue for road administration. Although numerous ways can be found to impute them in foreign literature (inter alia, the most effective method, that is Box-Jenkins models), in Poland, still only proven and simplified methods are applied. The article presents the analyses including an assessment of the completeness of the existing traffic data and works related to the construction of SARIMA model. The study was conducted on the basis of hourly traffic volumes, derived from the continuous traffic counts stations located in the national road network in Poland (Golden River stations) from the years 2005 – 2010. As a result, the proposed model was used to impute the missing data in the form of SARIMA (1.1,1)(0,1,1)168. The newly developed model can be used effectively to fill in the missing required days of measurement for estimating AADT by AASHTO method. In other cases, due to its accuracy and laboriousness of the process, it is not recommended.

Instrumented Mechanically Stabilized Earth Wall Reinforced with Polyester Straps

A wall of mechanically stabilized earth (MSE) with large concrete panel facing, reinforced with polyester straps, is an emerging technology in the United States. To enable the design of this wall system through AASHTO's methodology, the system's classification of extensibility must be established. Therefore, a section of such a wall was instrumented as part of a newly constructed interchange on I-95 at Christiana, Delaware. The section was one of several similar walls that allow access to bridges composing the interchange. Monitoring included tensile force distribution at selected straps and force at the connection of a few straps to the large concrete panels. The recorded data were from April 2012, the beginning of construction of the instrumented wall, to June 2014, about 20 months after construction ended. When this reinforced wall system was classified as extensible, the maximum load in the straps and connections was about one-fourth the predicted value from using the AASHTO method, and the lengths of the reinforcing straps were adequate to enable the wall to sustain the required loads. The indicated conservatism of the measured versus the predicted maximum load in the reinforcements was attributed to significant underestimation of the reinforced soil strength in AASHTO's design and, potentially, to a large toe resistance. The data suggest that AASHTO's design, which is based on extensible reinforcement for this family of MSE walls, is adequate.

STUDY ON COMPARATIVE FLEXIBLE PAVEMENT THICKNESS ANALYSIS USING VARIOUS DESIGN METHOD

Recently, there is a lot of variability in guide to design a pavement. Although all kinds method available, but still pavement suffers damage caused by unstable thickness. It is critical to determine the most appropriate pavement thickness for a given traffic level and subgrade condition. To overcome the problems, there is a need to study the comparative pavement thickness analysis using various pavement design methods so that it will be cost effective and long lasting. The input parameters in flexible pavement design are identified and have been used in obtaining different pavement layer thickness by conducting various pavement design method, that is Arahan Teknik (Jalan) 5/85 Jabatan Kerja Raya (JKR), AASHTO Method and Asphalt Institute Thickness Design Program (SW-1). Finding from this study indicate that thickness from Arahan Teknik (Jalan) 5/85 Jabatan Kerja Raya (JKR) gave better results than the others because it produced more thinner flexible pavement layer compared to the two other design method. In terms of cost, it will be more cost effective since the cost of material can be reduced.

Evaluation of Resilient Modulus Test Protocols for New Mexico Subgrade Soil

Resilient modulus (MR) is a laboratory determined parameter of pavement subgrade soil which is an important design input for the Mechanistic Empirical Pavement Design Guide (MEPDG). There are two accepted laboratory testing protocols for determining MR, namely AASHTO T307 and NCHRP 1-28A. AASHTO method is more popular because of its simplicity in positioning the load and deformation transducers. This study is undertaken to examine the available test protocols for New Mexico subgrade soil by varying the location of deformation transducers and effects of sample size. AASHTO A-6 subgrade soils have been collected from the state of New Mexico, USA. Specimens of 2.8 inch and 4 inch diameters are reconstituted using modified proctor compaction.Resilient modulus values aredetermined using external and internal deformation techniques. Comparative analyses are performed and amount of extraneous large deformation (lower MR) measured by the AASHTO recommended external deformation transducers is measured.In addition, appropriate internal deformation measurement methods are recommended to obtain most consistent MR values. 2.8 inch and 4 inch diameter sample generate almost similar MR values.