scholarly journals Investigation of Different Laboratory Aging Methods of Bituminous Mixtures

2021 ◽  
Author(s):  
Cagla Durmaz ◽  
Burak Sengoz ◽  
Derya Kaya Ozdemir ◽  
Ali Topal
Keyword(s):  
Aging Condition ◽  
Short Term ◽  
Current Standard ◽  
Forced Draft Oven ◽  
The Road ◽  
Bituminous Mixtures ◽  
Pavement Surface ◽  
Aging Properties ◽  
Indirect Tensile ◽  
Forced Draft

The predicted performance and service life of the pavement depend largely on the properties of bitumen used in the mixtures. The most important feature of bitumen, which has profound effect on the performance of the road is durability. The durability of bitumen is expressed as the resistance to aging. In this study, the bituminous mixture aging was performed instead of bitumen aging in order to represent the aging in the field in the best possible way. The aim of this paper is to evaluate different proposed laboratory aging methods (NCHRP 09-52, NCHRP 09-54 and RILEM) in relation with the current Standard AASHTO R30 (Standard Practice For Mixture Conditioning of Hot Mix Asphalt standard) and to make comparison with the samples performance taken from the field in terms of Indirect Tensile Strength (ITS). The level of aging has also been compared with the samples taken from recently constructed pavement surface and from the five years old pavement surface. Results depicted that, laboratory aging methods revealed the field aging properties on the unaged bitumen. Based on the results, 2 hours forced draft oven aging at 135°C is recommended as short term aging condition because, 2 hours or 4 hours short term forced draft oven aging did not yield significant variation in terms of ITS values. Additionally, 120 hours (5 days) oven aging of compacted samples at 85°C can be recommended as long term aging condition.

scholarly journals Road Short-Term Travel Time Prediction Method Based on Flow Spatial Distribution and the Relations

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Mingjun Deng ◽  
Shiru Qu
Keyword(s):  
Time Series ◽  
Spatial Distribution ◽  
Travel Time ◽  
Nonparametric Regression ◽  
Nearest Neighbor ◽  
Nearest Neighbor Search ◽  
Short Term ◽  
Combination Model ◽  
The Road ◽  
Neighbor Search

There are many short-term road travel time forecasting studies based on time series, but indeed, road travel time not only relies on the historical travel time series, but also depends on the road and its adjacent sections history flow. However, few studies have considered that. This paper is based on the correlation of flow spatial distribution and the road travel time series, applying nearest neighbor and nonparametric regression method to build a forecasting model. In aspect of spatial nearest neighbor search, three different space distances are defined. In addition, two forecasting functions are introduced: one combines the forecasting value by mean weight and the other uses the reciprocal of nearest neighbors distance as combined weight. Three different distances are applied in nearest neighbor search, which apply to the two forecasting functions. For travel time series, the nearest neighbor and nonparametric regression are applied too. Then minimizing forecast error variance is utilized as an objective to establish the combination model. The empirical results show that the combination model can improve the forecast performance obviously. Besides, the experimental results of the evaluation for the computational complexity show that the proposed method can satisfy the real-time requirement.

The Road Back to Full Employment

1993 ◽  
Vol 4 (2) ◽  
pp. 176-197
Author(s):  
Fred Argy
Keyword(s):  
Economic Development ◽  
Unemployment Rate ◽  
Full Employment ◽  
Incentive Structure ◽  
Short Term ◽  
The Road ◽  
Australian Economy ◽  
Year 2000 ◽  
Wage Outcomes ◽  
Major Project

Over the last two years the Committee for Economic Development of Australia (CEDA) carried out a major project: a vision for the Australian economy and practical policies to attain that vision by the year 2000. One of the key goals was to halve the official unemployment rate. The results are outlined in this article. Emphasis is placed on a policy and incentive structure that is skewed in favour of exports, productive investment and savings, a more structurally efficient and flexible labour market, responsible aggregate wage outcomes and acceptance that growth is only sustainable if the short—term costs of structural reform are borne equitably.

scholarly journals Application of the foamed bitumen and bitumen emulsion to the road base mixes in the deep cold recycling technology

2016 ◽  
Vol 11 (4) ◽  
pp. 291-301 ◽  
Author(s):  
Marek Iwański ◽  
Anna Chomicz-Kowalska
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Base Layer ◽  
The Road ◽  
Road Base ◽  
Bitumen Emulsion ◽  
Recycling Technology ◽  
Indirect Tensile ◽  
Foamed Bitumen ◽  
Cold Recycling

This paper presents findings of a study concerning the influence of binder type on the mechanical properties of road base in the cold recycling technology. The principal aim of this investigation was to evaluate the mixes in scope of susceptibility to moisture and low-temperatures. In the comparative research foamed bitumen and bitumen emulsion were used in four different concentrations (2.0%, 2.5%, 3.0%, 3.5%). The materials used in the study were reclaimed from an existing road construction layers: reclaimed aggregate from the road base and reclaimed asphalt pavement obtained by milling the surface and binder course. Portland cement in 2.0% concentration was used as a hydraulic binder. The evaluated parameters were: indirect tensile strengths, tensile strength retained and indirect tensile stiffness modulus at 25 °C. These tests were complemented by an evaluation of susceptibility to moisture and frost according to modified procedures implemented by American researchers: Tunnicliff, Root and Lottman. Moreover, tests for low-temperature cracking were conducted according to Finnish standard. The investigations showed that the use of foamed bitumen for road base layer produced in the cold recycling technology results in better mechanical properties and resistance to moisture and frost compared to using bitumen emulsion. The use of 2.5% of foamed bitumen and 2.0% of Portland cement in the recycled road base allowed to meet the established criteria.

A Closer Look at the Culture of Infidelity

2020 ◽  
pp. 180-200
Author(s):  
Steven M. Ortiz
Keyword(s):  
Professional Sports ◽  
Short Term ◽  
The Road ◽  
Emotional Relationships ◽  
The World ◽  
On The Road ◽  
The One ◽  
Communication Methods

This chapter takes a deeper look at the culture of infidelity that pervades the world of professional sports, why wives share a universal fear that their husbands will be unfaithful, and how they are affected by the possibility or actuality that their husbands will engage in sexual or emotional relationships with other women. Three patterns of infidelity are identified in the context of the sport marriage: the one-time encounter, the short-term affair, and the long-term affair. The concept of suspicion work is introduced to examine how wives try to manage the fear that their husbands may succumb to temptation and to specify how denial can be part of this process. The chapter discusses re-entry routines and communication methods some couples use when husbands return from travel, and the boundaries of fidelity and forgiveness wives establish as they attempt to cope with the realities of their husbands’ lives on the road.

Materials for Well Integrity: Characterization of Short-Term Mechanical Properties

2020 ◽  
Author(s):  
Mohammadreza Kamali ◽  
Mahmoud Khalifeh ◽  
Arild Saasen ◽  
Laurent Delabroy
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strength Reduction ◽  
Indirect Tensile Strength ◽  
Short Term ◽  
Indirect Tensile ◽  
Expansive Cement

Abstract Integrated zonal isolation is well-known as a key parameter for safe drilling operation and well completion of oil and gas wells. An extensive research on alternative materials has been conducted in the past concerning primary cementing, overcoming annular leaks, and permanent well abandonment. The present article focuses on geopolymers, expansive cement, pozzolan based sealant and thermosetting resins. The viscous behavior and the pumpability of the different materials have been investigated and benchmarked with the properties of neat class G Portland cement. The current study includes short-term mechanical properties of the above-mentioned materials. These properties include compressive strength development, Young’s modulus, indirect tensile strength, and sonic strength. The tests are performed in accordance with API 10B-2 and ASTM D3967-16 for all the materials for 1, 3, 5, and 7-day of curing at 90°C and elevated (172 bar) and atmospheric pressures. Our results show a mixed behavior from the materials. According to uniaxial compressive test results, all the candidate barrier materials developed strength during the considered period; however, the geopolymer and pozzolanic-based mixture did not develop early strength. The expansive cement showed an acceptable early compressive strength, but strength reduction was noticed after some time. The strength reduction of expansive cement was also observed for the indirect tensile strength. All the materials become stiffer overtime as they made more strength. For the neat class G cement and expansive cement, the Young’s modulus showed a minimum after 5 days, but it was increased.

Moisture Sensitivity of Bituminous Mixtures with Compound Fly Ash Modifier

2012 ◽  
Vol 509 ◽  
pp. 149-154
Author(s):  
Jun Xie ◽  
Jun Cai ◽  
Shao Peng Wu ◽  
Ling Pang
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Fly Ash ◽  
Moisture Damage ◽  
Moisture Sensitivity ◽  
Bituminous Mixtures ◽  
Primary Object ◽  
New Type ◽  
Indirect Tensile ◽  
Short Span

Bitumen pavement suffers from moisture damage mainly due to loss of durability and stability in a short span of service life. Filler is known to be capable of increasing the stiffness of bitumen binder, contributing to improvement of moisture sensitivity of bitumen mixture. In this paper a new type of filler named 'Compound Fly Ash Modifier' (CFAM) was introduced in order to enhance the bond strength between acidic aggregate with bitumen. The primary object is to determine the effect of CFAM on the moisture sensitivity of bitumen mixtures prepared by gneiss and granite respectively, which are termed acidic aggregate. Modified Lottman test and fatigue test were conducted. The results show that CFAM improves the resistance of mixes to moisture damage in the increase in indirect tensile strength and the extension of fatigue life. Finally the mechanism of modified effects for CFAM is discussed.

Development of New Low-Cost Indirect Tensile Test Equipment for Bituminous Mixtures

2001 ◽  
Vol 29 (4) ◽  
pp. 387 ◽  
Author(s):  
DR Petersen ◽  
RE Link ◽  
M Tigdemir ◽  
M Karasahin ◽  
SF Kalyoncuoglu
Keyword(s):  
Tensile Test ◽  
Low Cost ◽  
Test Equipment ◽  
Bituminous Mixtures ◽  
Indirect Tensile Test ◽  
Indirect Tensile

scholarly journals Influence of Gradation on the Mechanical Properties of Aged Hot-Mix Asphalts

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 632
Author(s):  
Saieth Baudilio Chaves-Pabón ◽  
Hugo Alexander Rondón-Quintana ◽  
Carlos Alfonso Zafra-Mejía
Keyword(s):  
Mechanical Properties ◽  
Cyclic Load ◽  
Stress Condition ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Short Term ◽  
Clear Trend ◽  
Indirect Tensile ◽  
Effects Of Aging

When a hot-mix asphalt (HMA) ages, its mechanical properties, resistance, and durability change. Several studies have been conducted throughout the world to evaluate the effects of aging in HMAs. However, few studies have analyzed the influence of gradation. The main objective of this study was to evaluate the influence of gradation on the mechanical properties of aged HMA mixes. For such purposes, three HMA mixes with different gradations were manufactured (named HMA-10, HMA-19, and HMA-25), which were conditioned in STOA (short-term oven aging) and LTOA (long-term oven aging) by following the guidelines established by the AASHTO R30 specification. Marshall, Indirect Tensile Strength (ITS), resilient modulus, permanent deformation, fatigue (under controlled-stress condition), and Cantabro tests were performed. These tests were carried out to evaluate resistance under monotonic and cyclic load as well as the resistance to moisture damage and abrasion. The best performing mix in the test was HMA-19. There is no clear trend about the influence of gradation over the susceptibility of mixes for aging. This susceptibility changes depending on the test performed and the property measured. Furthermore, in resilient modulus tests, it is observed that the influence of gradation on aging susceptibility changes depending on the test temperature.

scholarly journals Advantages Of Filler And Surfactant Additive To Improve Moisture Sensitivity Of Hot Mix Asphalt Mixtures.

2021 ◽  
Vol 1202 (1) ◽  
pp. 012011
Author(s):  
Asres Simeneh ◽  
Alamrew ◽  
Konrad Mollenhauer
Keyword(s):  
Tensile Strength ◽  
Mineral Composition ◽  
Hydrated Lime ◽  
Moisture Sensitivity ◽  
Bituminous Mixtures ◽  
Asphalt Mix ◽  
Indirect Tensile ◽  
Surfactant Additive ◽  
Long Term Performance ◽  
Term Performance

Abstract This research investigated the effect of mineral composition of aggregate on moisture sensitivity of bituminous mixtures and explored the benefits of hydrated lime filler and Wetfix BE surfactant additive to improve the resistance of the mix against moisture sensitivity. Basalt, quartzite, and limestone aggregates were selected based on their different mineralogy and 70 -100 penetration graded bitumen binders used during the study. Four laboratory tests the rolling bottle, shaking abrasion, pull-off tensile strength and indirect tensile strength tests were applied to study the effects of aggregate minerals and benefits of hydrated lime and Wetfix BE. Statistical analysis using Two-way ANOVA test conducted for each test to check the outcome significance. Results from each test revealed that mineral composition of aggregate have significant effects on the moisture resistance performance of bituminous mixtures and hydrated lime filler and Wetfix BE surfactant additives have advantages to improve the performance of bituminous mixture against moisture sensitivity and improves the long-term performance of asphalt mix.

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