Ruggedness Evaluation and Precision Estimates for Newly Developed Test Methods for Asphalt-Treated Cold Recycled Pavements

Author(s):  
Adam J. T. Hand ◽  
Ilker Boz ◽  
Murugaiyah Piratheepan ◽  
Forrest Hierholzer ◽  
Brian K. Diefenderfer ◽  
...  

Asphalt-treated cold recycled pavements, including cold in place recycling, full depth reclamation, and cold central plant recycling, are becoming popular rehabilitation options because they are economical, sustainable, and provide good performance. Because asphalt-treated cold recycled pavements use foamed or emulsified binder, they require a curing period post-construction before being opened to traffic or surfaced. Uniform guidelines on when an asphalt-treated cold recycled roadway can be opened to traffic or surfaced are not widely established, many are based on time or moisture content, and extreme ranges exist among agency specifications. Mixture designs also vary widely among agencies with regard to active filler use and asphalt recycling agents, further complicating the determination of necessary curing time. NCHRP Project 09-62 investigated a variety of test methods for determining when a recycled roadway could be opened to traffic or surfaced. This included extensive laboratory and field evaluations. New shear strength and raveling test methods were developed. For each test method a ruggedness study and inter-laboratory study were performed. The ruggedness study revealed critical test fixture and operation parameters. Six asphalt-treated cold recycled pavement process/material combinations were tested by three entities to develop precision estimates and statements (i.e., repeatability and reproducibility) for the new test methods. Tools and information from this study provide a rational basis for establishing specifications, which will help reduce pavement damage from early traffic and minimize roadway closures and delays.

2014 ◽  
Vol 587-589 ◽  
pp. 947-951
Author(s):  
Jun Yong Liu ◽  
Liu Jun Zhang

The test methods provided by current related "specifications" do not apply to saline soil soft foundation bearing capacity test. Through discussing the limitations of the related specifications and based on the experience on saline soil soft ground capacity test, the paper made some improvements of test on such aspects: conditions of loading and stopping load, determination of the characteristic value of the ground bearing capacity and evaluation, the paper also put forward the saline soil soft ground capacity test method.


Author(s):  
A. S. Alekseeva ◽  
T. B. Shemeryankina ◽  
M. N. Lyakina ◽  
M. S. Smirnova ◽  
E. P. Fedorova ◽  
...  

Vitamin A is present in multivitamin products mainly in the form of retinol esters: retinyl acetate, retinyl palmitate, and beta carotene—retinol precursor (dimer) found in plants, which is capable of converting into retinol in liver cells. Retinol is determined in medicinal products primarily by high performance liquid chromatography (HPLC), with preliminary purification and vitamin isolation by liquid-liquid extraction. However, scientific literature also describes other methods of sample preparation and analysis of such compounds. An important issue is differentiation of vitamin A from other fat-soluble vitamins often included as components in multivitamin products. The aim of the study was to analyse and summarise data on current methods used for determination of vitamin A and its derivatives in medicinal products. The authors analysed the range of vitamin A products authorised in the Russian Federation, and the test methods described in their product specification files. The study demonstrated that the test method most often used for determination of retinol esters was HPLC with isocratic elution mode using octadecylsilyl packing in the reverse-phase mode, and, less frequently, aminopropylsilyl packing in the normal phase mode. Determination of beta carotene in medicinal products is most often performed using spectrophotometry. 


2019 ◽  
Vol 85 (7) ◽  
pp. 41-49
Author(s):  
Yaroslava V. Sulimina ◽  
Nikolay O. Yakovlev ◽  
Vladimir S. Erasov ◽  
Aleksey Yu. Ampilogov ◽  
Andrey N. Polyakov ◽  
...  

The special features of various bearing deformation measurements for pin-type bearing tests of metallic materials are considered along with their impact on the magnitude of the «bearing elastic modulus» and bearing stress. These bearing test methods are present in ASTM and various institutional standards, though no state standard (GOST, GOST R) is currently available for bearing test method of metallic materials. Analysis of additional deformations which arise in determining the degree of hole bearing deformation is carried out. A set of sources of additional deformations is shown to be characteristic for each test procedure and is attributed to the design features of the device, the site and a way of mounting the extensometer. Additional deformations can be both tensile and compressive. It is shown that the impact of additional deformations on the «bearing elastic modulus» is limited to 14% for different procedures. No difference between the methods is revealed with regard to determination of the strength characteristics. At the same time the dispersion decreases with increase in plastic deformation and for bearing deformation about 4% the variation coefficient for all methods is no more than 1%. Advantages and shortcomings of the bearing test methods which affect the reproducibility of the results are considered. The effect of the specimen geometry on the bearing characteristics is considered. It is shown that increase both in the distance from the edge of the bearing specimen to the center of the hole for 1163T, VT6ch, 30KhGSA alloys and residual bearing deformation up to 6%, increase bearing strength characteristics.


2015 ◽  
Vol 27 (4) ◽  
pp. 476-488 ◽  
Author(s):  
Nellie Gagné ◽  
Anne Veniot ◽  
Mary Stephenson ◽  
Carol McClure

Fitness for purpose and validation are increasingly becoming a benchmark in the development of test methods for the diagnosis of infectious diseases in aquatic animals. The design of the evaluation and the analysis of data are critical to demonstrate test method performance characteristics and fitness for purpose, as stated in the World Organization for Animal Health pathway for test validation. Three test methods for the detection of the oyster parasite Haplosporidium nelsoni were selected for the validation study described herein: histology, end-point polymerase chain reaction (PCR), and real-time PCR (qPCR). Preliminary work evaluated the analytical sensitivity and specificity of the PCR and qPCR assay in development. The following stage used test results on 100 oysters in 3 different laboratories to assess diagnostic sensitivity (DSe), diagnostic specificity (DSp), repeatability, and reproducibility. Repeatability and reproducibility were within 68–95%. The final part of the project evaluated DSe and DSp using test results on 400 oysters and results from the first 100 oysters tested. In the absence of a 100% gold standard test, latent class modeling methods were explored to characterize the tests (i.e., Bayesian analyses). For both PCR methods, DSe was >90%, and in the 60% range for histology, whereas DSp was >90% for all methods. Based on the results of this validation, a threshold cycle value of 30 for qPCR corresponds to the limit of sensitivity for histology where unreliable detection becomes more frequent, thus providing a threshold helpful in diagnostic settings where both histology and qPCR are used.


1973 ◽  
Vol 187 (1) ◽  
pp. 405-412
Author(s):  
J. Whitaker

To contend with installation variants the fan must be tested in a system that resembles its site installation. Four simplified system arrangements are covered with two inlet test methods—ducted inlet and free inlet—by adding ducts to the free discharge. With free inlet tests a plenum chamber is attached to the fan inlet in order to obtain the required measurements; investigations to provide information concerning the optimum configuration of this test method are described. Determination of static pressure, selection of inlet devices for flow measurement; simulation of inlet and outlet ducts and the method of loading are also discussed.


2014 ◽  
Vol 1038 ◽  
pp. 115-120 ◽  
Author(s):  
Christian Goth ◽  
Thomas Kuhn ◽  
Gerald Gion ◽  
Jörg Franke

The adhesion test of metallic structures on MID (Molded Interconnect Devices) parts is an unsolved issue. So far no method really works reliably. The test methods which are conventionally used are the pull-off test and the shear-test. Both show large standard deviation and the reproducibility is not assured. Nordson DAGE has introduced the new micro-material testing system 4000Plus. This device enables a new test method for the determination of the adhesion strength of MID structures using the hot pin pull (hot bump pull) method. Copper pins (tinned or untinned) are heated up with a user defined temperature profile, soldered to a metallized structure on the MID and then removed vertically upward, while the force is recorded. In this contribution investigations with this new test method are presented.


1973 ◽  
Vol 187 (1) ◽  
pp. 405-412
Author(s):  
J. Whitaker

To contend with installation variants the fan must be tested in a system that resembles its site installation. Four simplified system arrangements are covered with two inlet test methods—ducted inlet and free inlet—by adding ducts to the free discharge. With free inlet tests a plenum chamber is attached to the fan inlet in order to obtain the required measurements; investigations to provide information concerning the optimum configuration of this test method are described. Determination of static pressure, selection of inlet devices for flow measurement; simulation of inlet and outlet ducts and the method of loading are also discussed.


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