Recommendations for the design of structures subject to traffic loading to BS EN 1997-1:2004

2020 ◽  
Keyword(s):  
Traffic Loading

Effect of Healing on Fatigue Law Parameters of Asphalt Binders

2012 ◽  
Vol 2293 (1) ◽  
pp. 96-105 ◽  
Author(s):  
Arianna Stimilli ◽  
Cassie Hintz ◽  
Zhijun Li ◽  
Raul Velasquez ◽  
Hussain U. Bahia
Keyword(s):  
Fatigue Life ◽  
Asphalt Binder ◽  
Rest Period ◽  
Power Laws ◽  
Asphalt Binders ◽  
Traffic Loading ◽  
Damage Level ◽  
Rest Periods ◽  
Pavement Structure ◽  
Number Of Cycles

Asphalt binder has the ability to self-heal during rest periods when repetitive loading is applied. Studying the effect of rest on fatigue law parameters provides useful insight into the healing capabilities of asphalt binders. Currently, standard testing and analysis procedures to quantify asphalt binder healing capability are limited and difficult to implement in practice. Fatigue is known to depend on both traffic loading and pavement structure. Power law relations (e.g., Nf = Aγ−B) are commonly used for fatigue analysis of pavement materials. Power laws are used to estimate fatigue life (i.e., number of cycles to failure, Nf) as a function of load amplitude (e.g., strain, γ), which is a reflection of the pavement structure. In this study, testing consisted of strain-controlled time sweeps in the dynamic shear rheometer with a single rest period inserted at a specified damage level. With the selected test, the effect of healing on the relationship between fatigue life and strain was investigated. Nine neat and modified binders were tested. Healing testing was conducted at multiple age levels and strains. Healing that resulted from a single rest period had an insignificant effect on fatigue performance compared with modification and oxidative aging. Although this paper highlights the challenges of using few rest periods to predict healing potential, preliminary results of testing with multiple rest periods show the importance of healing. Further investigation is needed to verify the effect of multiple rest periods on binder fatigue.

Study on Load Stress of Lean Concrete Base in Asphalt Pavement

2012 ◽  
Vol 178-181 ◽  
pp. 1495-1498
Author(s):  
Li Jun Suo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Asphalt Pavement ◽  
Element Model ◽  
Pavement Design ◽  
The Other ◽  
Three Dimension ◽  
Traffic Loading ◽  
Concrete Base

Load stress, which is caused by traffic loading, is important parameter used in the analysis of the new pavement design. In order to study the load stress of lean concrete base in the asphalt pavement, first of all, three–dimension finite element model of the asphalt pavement is established. The main objectives of the paper are investigated. One is calculation for load stress of lean concrete base, and the other is analysis for relationship between load stress of lean concrete base and parameters, such as thickness, modulus. The results show that load stress of lean concrete base decreases, decreases and increases with increase of base’s thickness, surface’s thickness and ratio of base’s modulus to foundation’s modulus respectively. So far as the traffic axle loading is concerned, it has a significant impact on load stress of lean concrete base, and it can be seen from results that when load is taken from 100kN to 220kN, load stress increases quickly with the increase of the traffic axle loading.

Stress Analysis of a Gas Pipeline Installed Using HDD and Auger Bore Techniques

2008 ◽  
Author(s):  
Paul Cousens ◽  
Chas Jandu
Keyword(s):  
Natural Gas ◽  
Stress Analysis ◽  
Transmission Network ◽  
Storage Facility ◽  
Directional Drilling ◽  
Sources Of Information ◽  
Horizontal Directional Drilling ◽  
Design Code ◽  
Traffic Loading ◽  
Natural Gas Transmission

As part of an important project to reinforce the natural gas transmission network, a new pipeline has been constructed to transport natural gas from a major UK LNG storage facility into the national transmission system. The project involved the installation of several sections by trenchless methods, namely auger boring for a number of road crossings and significant lengths of horizontal directional drilling (HDD) beneath railroads, canals and marshland. The installation of pipelines using trenchless techniques such as HDD continues to increase in popularity. The various methods available offer advantages over traditional open cut techniques, in particular much reduced disruption during the construction of road and rail crossings. Furthermore, increased awareness and responsibility towards the environment leads us to seek installation methods that cause the least disruption at the surface and have the least impact to the environment. It was required to assess the proposed crossing designs against acceptable stress limits set out in company specifications and against the requirements of UK design code IGE/TD/1 Edition 4 [1], which requires that ‘additional loads’ such as soil loadings, thermal loads, settlement and traffic loading are accounted for within the stress calculations. However, it does not stipulate the sources of such equations and the pipeline engineer must rely on other methods and published sources of information. This paper presents the method used to analyse those sections of the new pipeline installed by auger boring and HDD focusing on the methods and formulae used to calculate the stresses in the pipeline from all loading sources.

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. 

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