Evaluation of permanent deformation of multilayer porous asphalt courses using an advanced multiply-repeated load test

Simple performance tests (SPTs) to be used with the Superpave® volumetric mixture design procedure were recently recommended by NCHRP Project 9-19 (Simple Performance Test for Superpave Mix Design). Field validation of the SPTs is critical to their final acceptance and implementation in Superpave mixture design practice. Special Pavement Studies-1 (SPS-1) prematurely rutted sections on US-281 in Texas were used to validate the SPTs for permanent deformation, including the dynamic modulus test and repeated-load test and associated rutting indicators E*/sin δ and flow number ( F n), respectively. The results of this case study clearly show that both the dynamic modulus test and E*/sin δ and the repeated-load test and F n can effectively distinguish the good mixtures from the bad. Compared with E*/sin δ, F n can better differentiate the performance of asphalt mixtures. These results preliminarily validated both SPTs for permanent deformation. In addition, the location of the tertiary point in the plot of permanent strain versus number of load repetitions is clarified; a simple linear model needs to be added in order to determine the F n. Furthermore, the possibility of using the number of load repetitions ( Nps) corresponding to the initial point of the secondary stage to characterize the rutting resistance of asphalt mixtures is discussed. The new indicator proposed is supported by the limited data presented in this paper and can be easily determined and can reduce test duration significantly.

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Permanent Deformation of Steel under Slowly Repeated Load

journal of the Japan Society for Testing Materials ◽

10.2472/jsms1952.3.314 ◽

1954 ◽

Vol 3 (15) ◽

pp. 314-317

Author(s):

Minoru KAWAMOTO ◽

Tadakazu SAKURAI ◽

Morio SEKI

Keyword(s):

Permanent Deformation ◽

Repeated Load

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Investigating the Permanent Deformation Behavior of Asphalt Concrete Mixtures in Repeated Load Creep Tests

International Conference on Transportation and Development 2016 ◽

10.1061/9780784479926.088 ◽

2016 ◽

Cited By ~ 1

Author(s):

Nader Mahmoodinia ◽

Mohammad Molayem ◽

Alireza Fardealirezaei

Keyword(s):

Asphalt Concrete ◽

Deformation Behavior ◽

Permanent Deformation ◽

Creep Tests ◽

Concrete Mixtures ◽

Repeated Load

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Evaluation of All-Round Modular Scaffolding (ARMS) type Scaffold by using BS1139 Standards for Industries

Journal of Advanced Mechanical Engineering Applications ◽

10.30880/jamea.2021.02.01.006 ◽

2021 ◽

Vol 02 (01) ◽

Author(s):

M.S. Yob ◽

◽

N.A. Mat Tahir ◽

M.J. Abd Latif ◽

M.F. Mohd Hassim ◽

...

Keyword(s):

Permanent Deformation ◽

Load Test ◽

Heavy Duty ◽

Distributed Load ◽

Safety And Health ◽

The Government ◽

The Individual

Scaffolds can be categorised into access scaffolds and support scaffolds based on its functions: access scaffolds and support scaffolds. Regardless, both are only consent to be used when it follows requirement set forth by the government in order to protect the workers’ safety and health. Due to increased demand for scaffolds manufacturers try to compete with each other by developing various type and sizes of scaffolds. Unfortunately, the usage of these modern scaffolds such as All-Round Modular Scaffoldings are rather limited due to its deviations from the BS 1139 standards. This study aims to determine the distribution force on the All-Round Modular Scaffolding determine its suitable duty category based on the BS1139 guidelines. Standard parts of ARMS from manufacturer was used to build one storey x 1 bay (sizing 3 m x 3 m) structure and was assembled by authorised and professional contractor. The structure was then put through load test. The load was placed on top of the working platform and the deflection of the components was measured. The findings reveal that the structure as well as the individual platform can support loads up to 500 kg with no crack or permanent deformation observed after the test. By referring the BS1139 standards, the All-Round Modular Scaffolding is surpassing the requirement for general and heavy-duty scaffold with distributed load on platform recorded to be 2.67 kN/m2 and concluded that the additional length of the components does not compromise the working purpose of the scaffolds.

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