Estimating Results of a Proposed Simple Performance Test for Hot-Mix Asphalt from Superpave Gyratory Compactor Results

2005 ◽  
Vol 1929 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Ahmed F. Faheem ◽  
Hussain U. Bahia ◽  
Hossein Ajideh
Keyword(s):  
Performance Test ◽  
Test Procedure ◽  
Asphalt Mixtures ◽  
Strongly Correlated ◽  
Flow Number ◽  
Traffic Loading ◽  
Superpave Gyratory Compactor ◽  
The Stability ◽  
Work Done ◽  
Pavement Service Life

This study intended to use the Superpave® gyratory compactor (SGC) as a basis for estimating the stability of asphalt mixtures as a surrogate for proposed method for the simple performance test. Several asphalt mixtures were produced with varying aggregate sources, asphalt contents, and gradations. Every mixture was compacted with the SGC and evaluated with the repeated compression test procedure for rutting measurements recommended by NCHRP Project 9–19 and the AASHTO 2002 pavement design manual to evaluate whether the results from the SGC can be related to the rutting of mixtures. Densification curves produced by the SGC were used to determine the volumetric properties besides the calculation of the traffic densification index (TDI), which represents the densification experienced by traffic loading during pavement service life. The traffic force index (TFI) was also calculated with a special accessory added to the SGC during compaction (the pressure distributor analyzer). The TFI represents the work done by the traffic to densify the mixture. Results from the mixture rutting tests were used to estimate the flow number (FN). The FN, an important mixture property, is shown to have a strong correlation to the TFI. The TFI was also found to be strongly correlated with the TDI and gives an opportunity to estimate the mixture resistance to compaction forces with the use of its volumetric behavior. The main finding of the study is that the SGC appears to give information that can be used to characterize the stability of the mixtures. Such information could be used as an initial screening criterion to select mixtures for various traffic levels.

Aggregate Degradation Characteristics of Stone Mastic Asphalt Mixtures

2013 ◽  
Vol 65 (3) ◽  
Author(s):  
Mohd. Rosli Hainin ◽  
Norliza Mohd Akhir ◽  
Ramadhansyah Putra Jaya ◽  
Nur Izzi Md. Yusoff ◽  
Haryati Yaacob ◽  
...  
Keyword(s):  
Coarse Aggregate ◽  
Asphalt Mixtures ◽  
Compaction Process ◽  
Traffic Loading ◽  
Coarse Aggregates ◽  
Mastic Asphalt ◽  
Superpave Gyratory Compactor ◽  
Stone Mastic Asphalt ◽  
The Relationship ◽  
Compaction Method

Stone Mastic Asphalt (SMA) mixtures are designed to have a high coarse aggregate content and stone-on-stone contact, which results in more stress on the coarse aggregates during compaction and traffic loading. As a result, aggregates tend to break down more in SMA mixtures than in conventional dense graded mixtures. Aggregate degradation during compaction and traffic loading may cause changes in the original gradation and thus may also affect the volumetric parameters of SMA mixtures. Therefore, this  study was conducted to determine the degree of aggregate degradation in SMA mixtures due to the compaction process. Aggregates of two Nominal Maximum Aggregates Sizes (NMAS), designated as SMA14 and SMA20, were compacted using 50 blows of the Marshall Hammer and 100 gyrations of the Superpave Gyratory Compactor (SGC). The verified samples were then prepared and extracted using the Centrifuge Method. The relationship between aggregate degradation and influencing factors, such as compaction effort and volumetric properties were investigated. Aggregate degradation by the Marshall Hammer was found to be significantly higher than degradation by the SGC. Voids in the mineral aggregate (VMA) of either compaction method decrease or are almost the same when aggregate degradation is not significant. SGC method can be selected to represent the field roller that results in a similar trend of aggregate degradation.

Flow Number Test and Assessment of AASHTO TP 79-13 Rutting Criteria

2015 ◽  
Vol 2507 (1) ◽  
pp. 100-107 ◽  
Author(s):  
Maria Carolina Rodezno ◽  
Randy West ◽  
Adam Taylor
Keyword(s):  
Performance Test ◽  
Hot Mix Asphalt ◽  
Warm Mix Asphalt ◽  
Asphalt Mixtures ◽  
Standard Protocol ◽  
Test Results ◽  
Flow Number ◽  
Test Parameters ◽  
Traffic Level ◽  
Tp 79

The flow number (FN) test was recommended in NCHRP Project 9-19 as a simple performance test for rutting evaluation of asphalt mixtures. The test showed good correlation with rutting performance of mixtures from WesTrack, MnROAD, and FHWA's accelerated loading facility. Despite this fact, no standard protocol was recommended for temperature and required stress level. Subsequent NCHRP studies allowed the development of a provisional standard. AASHTO TP 79-13 includes test parameters for stress and temperature, specimen conditioning, and minimum FN criteria that were established for hot-mix asphalt (HMA) and for warm-mix asphalt (WMA) on the basis of traffic level. In NCHRP Project 9-47A, the rutting potential of WMA mixtures was compared with that of HMA mixtures by using the FN test and the rutting criteria included in the AASHTO TP 79-13 were also evaluated. The analysis included results of samples produced by using field and lab mixtures. Thirteen mixes using 10 WMA technologies and eight corresponding HMA mixes were included. The FN test results for plant-produced WMA mixes were found to be statistically lower than those for corresponding HMA mixes in more than two-thirds of the comparisons. The study also found that the FN criteria recommended for both HMA and WMA seemed appropriate for evaluating plant-produced mixes. Another finding from the study was that FN results from lab-produced WMA mixtures were consistently lower than FN values from field mixtures; this result suggests that adjustments to the specimen conditioning requirements should be considered.

Flow Number parameter as a performance criteria for asphalt mixtures rutting: evaluation to mixes applied in Brazil Southern region

2021 ◽  
pp. 1-13
Author(s):  
Cléber Faccin ◽  
Luciano Pivoto Specht ◽  
Silvio Lisboa Schuster ◽  
Fernando Dekeper Boeira ◽  
Lucas Dotto Bueno ◽  
...  
Keyword(s):  
Asphalt Mixtures ◽  
Southern Region ◽  
Performance Criteria ◽  
Flow Number ◽  
A Performance

Dynamic analysis and control of an active engine mount system

2002 ◽  
Vol 216 (11) ◽  
pp. 921-931 ◽  
Author(s):  
Y-W Lee ◽  
C-W Lee
Keyword(s):  
Transfer Function ◽  
Dynamic Characteristics ◽  
Performance Test ◽  
Adaptive Controller ◽  
Lms Algorithm ◽  
Equivalent Mass ◽  
Engine Mount ◽  
Active Engine ◽  
The Stability ◽  
Mass Spring

Dynamic characteristics of a prototype active engine mount (AEM), designed on the basis of a hydraulic engine mount, have been investigated and an adaptive controller for the AEM has been designed. An equivalent mass-spring-damper AEM model is proposed, and the transfer function that describes the dynamic characteristics of the AEM is deduced from mathematical analysis of the model. The damping coefficient of the model is derived by considering the non-linear flow effect in the inertia track. Experiments confirmed that the model precisely describes the dynamic characteristics of the AEM. An adaptive controller using the filtered-X LMS algorithm is designed to cancel the force transmitted through the AEM. The stability of the LMS algorithm is guaranteed by using the secondary path transfer function derived on the basis of the dynamic model of the AEM. The performance test in the laboratory shows that the AEM system is capable of significantly reducing the force transmitted through the AEM.

AN OVERVIEW OF MOISTURE DAMAGE PERFORMANCE TESTS ON ASPHALT MIXTURES

2016 ◽  
Vol 78 (7-2) ◽  
Author(s):  
Fauzan Mohd Jakarni ◽  
Muhammad Fudhail Rosli ◽  
Nur Izzi Md Yusoff ◽  
Md Maniruzzaman A Aziz ◽  
Ratnasamy Muniandy ◽  
...  
Keyword(s):  
Moisture Damage ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Performance Tests ◽  
Cohesive Failure ◽  
Modified Bitumen ◽  
Traffic Loading ◽  
Construction Methods ◽  
Evaluation Phase ◽  
Two Phases

This paper presents a review of moisture damage performance tests on asphalt mixtures. The moisture damage remains to be a detriment to the durability of the Hot Mix Asphalt (HMA) pavement. Moisture damage can be defined in forms of adhesive failure between bitumen and aggregates and cohesive failure within bitumen. Aggregate mineralogy, bitumen characteristics and anti-stripping additive dominantly influence the performance of asphalt mixtures towards moisture damage alongside construction methods, climate and traffic loading. Various laboratory test methods have been developed to quantify the moisture damage performance of asphalt mixtures by resembles the action in the field, including qualitative test such as Boiling Water Test (ASTM D3625) and quantitative tests such as Modified Lottman Test (AASHTO T283). Both of these tests consist of two phases, which are conditioning and evaluation phase. This paper will review the effectiveness of the selected available tests based on various asphalt mixtures materials. Generally, this study indicates that asphalt mixtures consisted of limestone aggregates, modified bitumen and addition of anti-stripping additives will provide more resistant towards moisture damage. 

scholarly journals Mechanism of HCB-Modified Asphalt and Dynamic Properties of Mixtures

2020 ◽  
Vol 10 (14) ◽  
pp. 4971
Author(s):  
Zhan Ding ◽  
Jinfei Su ◽  
Peilong Li ◽  
Hui Bing
Keyword(s):  
Functional Groups ◽  
Oxygen Content ◽  
Performance Test ◽  
Dynamic Properties ◽  
Chemical Properties ◽  
Active Surface ◽  
Asphalt Mixtures ◽  
Low Frequencies ◽  
High Oxygen Content ◽  
Modified Asphalt

Hydroxymethyl carbon black (HCB) was prepared as an asphalt modifier with a high oxygen content and active surface chemical properties. The microstructure of HCB was analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The improvement effect of HCB on asphalt’s physical, dynamic shear, rheological, and aging properties was evaluated. To analyze the dynamic properties of the HCB-modified asphalt mixtures, a simple performance test (SPT) was conducted, and then the change laws of the dynamic modulus and phase angle for the HCB mixtures were clarified. The results showed that the surface of HCB is smooth and that the oxygen content increases with the generation of hydroxyl functional groups. Polar oxygen-containing functional groups and hydrogen bonds are helpful in improving the resistance to cracking and aging. The surface activity of HCB is susceptible to temperature and frequency, causing a slight influence of HCB on the viscoelasticity of asphalt mixtures at high and low frequencies. At low temperatures and high frequencies, the HCB enhanced the elasticity characteristics and weakened the viscosity characteristics of asphalt mixtures.

scholarly journals Detection of Self-Healing Discharge in Metallized Film Capacitors Using an Ultrasonic Method

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1893 ◽  
Author(s):  
Yusheng Ma ◽  
Haitao Shen ◽  
Chunming Pei ◽  
Huanyu Zhang ◽  
Muhammad Junaid ◽  
...  
Keyword(s):  
High Speed ◽  
Performance Test ◽  
Reactive Power ◽  
Ultrasonic Method ◽  
Test Procedure ◽  
Detection Algorithm ◽  
The Self ◽  
International Electrotechnical Commission ◽  
Self Healing ◽  
Ultrasonic Emission

Benefiting from self-healing features, metallized film capacitors (MFCs) are widely employed to compensate reactive power (VAR) and thus improve the performance of AC systems. To ensure the aforementioned functions, self-healing testing is a compulsory quality inspection for every type of MFC. In 2014, the International Electrotechnical Commission (IEC) issued a standard that recommended a general and instructive test procedure based on audible noise or ultrasound signals. However, more details relevant to this high voltage (HV) test were not provided. In this paper, we focused on the ultrasonic detection technique to reveal the self-healing characteristics of two typical MFCs. By launching a series of HV tests with star and delta MFCs, the waveform features, discharge energy, and spectrum distributions were analyzed. It was observed that the partial discharge always occurs before self-healing discharge with the same spectrum features ranging above 40 kHz. To solve the entanglement of these two discharge processes, a relative amplitude difference method is proposed. Based on the experimental observations, a detection algorithm incorporated with the ultrasonic emission sensors, preamplifier, and high-speed A/D converter was developed to assist the self-healing performance test.

On the Stability of Unsaturated Loess Slope under Tunneling Condition

2011 ◽  
Vol 233-235 ◽  
pp. 2678-2681 ◽  
Author(s):  
Xi An Li ◽  
Rong Jian Li ◽  
Gao Feng Che ◽  
Wen Zheng ◽  
Liang Li
Keyword(s):  
Critical Factor ◽  
Matric Suction ◽  
Strength Reduction ◽  
Sliding Surface ◽  
Negative Effects ◽  
Loess Slope ◽  
Stability Of Slope ◽  
The Stability ◽  
Unsaturated Loess ◽  
Work Done

As a unique mode of soil erosion, loess cavities often act as the critical factor to the stability of the highway slopes of unsaturated loess. In this paper, the unsaturated loess slope stabilities are comparatively studied in different cases through the developed program of the strength reduction FEM, such as loess cavities in different position, single- & twin cavities, occurrence and loss of matric suction etc. The work done in this paper revealed the mechanism how the tunneling and the matric suction have effect on the stability of unsaturated loess slope to some extent. The results not only indicate that the loess cavities favor to maintain the stability of slope with the cavities located near the slope's crest, while the loess cavities reduce the stability of slope with the cavities located near the slope's toe, but also disclose that the safety factor of the unsaturated loess slope increases and the potential sliding surface move downward with considering the matric suction and vice versa. In addition, the twin cavities near the slope's toe have the obvious negative effects on slope's stability.

Study on support characteristic curve of primary support structures in underground excavation considering bond-slip behavior

2020 ◽  
pp. 136943322095876
Author(s):  
Wei Lu ◽  
Huibin Sun
Keyword(s):  
Performance Test ◽  
Characteristic Curve ◽  
Mechanical Analysis ◽  
Bending Test ◽  
Underground Excavation ◽  
Bond Slip ◽  
Four Point Bending ◽  
Parametric Studies ◽  
The Stability ◽  
Shotcrete Lining

Steel reinforced shotcrete lining (SRSL) support is the primary structure to maintain the stability and mobilize the self-bearing capacity of surrounding rock. However, the structural design of SRSL in underground excavation still relies on experience-based method and lack of quantitative mechanical analysis. This paper aims to propose a modified analytical model of support characteristic curve (SCC) that represents the mechanical behavior of SRSL structures in underground construction, through which the interface bond-slip behavior between steel arch and shotcrete layer is taken into consideration. Four-point bending test of SRSL composite beam was carried out to study the bearing mechanism and failure performance. Test results show that the shotcrete-steel interface is prone to slip failure which significantly reduces the overall strength of SRSL. The laboratory test is complemented by non-liner finite element parametric studies considering the bond-slip properties to clarify the design principles and to obtain the flexural stiffness of tunnel primary lining structures. Based on above studies, the simplified formulas for the SCC of SRSL is constructed. The research results provide a theoretical basis for the design and application of SRSL structure in related projects.

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