scholarly journals Laboratory Evaluation and Construction of Fully Recycled Low-Temperature Asphalt for Low-Volume Roads

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Christiane Raab ◽  
Manfred N. Partl
Keyword(s):  
Ambient Temperature ◽  
Laboratory Experiments ◽  
Traffic Simulation ◽  
Traffic Load ◽  
Laboratory Evaluation ◽  
Small Scale ◽  
Medium Scale ◽  
Low Volume Roads ◽  
Low Volume

Growing economy and increasing pollution evoke the need for more environmentally friendly road construction techniques and the saving of natural resources. In this context, cold recycling plays an important role since, on the one hand, it allows to reduce CO2 emissions drastically and, on the other hand, it offers a variety of opportunities for high percentages of recycling. Inspired by experience in Sweden, the international project “Optimal Recycling of Reclaimed Asphalts for low-traffic Pavement” (ORRAP) for low-volume roads in the Upper Rhine region aims to develop and establish a new strategy for 100% reclaimed asphalt pavement (RAP) at ambient temperature (20°C) without adding virgin bituminous binders or rejuvenators. The still ongoing research project involves laboratory experiments as well as in situ test sections. The link between small-scale laboratory experiments and in situ testing is provided by medium-scale traffic simulation in the laboratory. This paper describes results from medium-scale compaction in the laboratory using different methods as well as traffic simulation with a medium-scale mobile traffic load simulator. The results show that compaction in the laboratory at ambient temperature (20°) is very difficult to achieve. Nevertheless, it was found that compaction at a temperature of 60°C appears possible and provides promising results regarding stability and rutting enabling the in situ construction. The in situ pavement construction at ambient temperature on a low-volume road in Switzerland resulted in a visibly well-compacted and stable base course which was covered by a hot mix asphalt surface course the day after. The test section will be monitored closely over the next 12 months.

Laboratory Testing of Low-Volume Road Bridge Alternative

1998 ◽  
Vol 1624 (1) ◽  
pp. 148-159 ◽  
Author(s):  
B. M. Phares ◽  
T. J. Wipf ◽  
F. W. Klaiber
Keyword(s):  
Load Distribution ◽  
Laboratory Testing ◽  
Concrete Surface ◽  
Small Scale ◽  
Steel Beams ◽  
Bridge Model ◽  
Low Volume Roads ◽  
Low Volume ◽  
Lateral Load Distribution ◽  
Concrete Deck

In Iowa there are over 20,000 bridges on the secondary road system. The majority of these bridges are under the jurisdiction of county engineers with limited budgets; therefore many county engineers design and construct their own short-span bridges with their own labor force. The objective of this research is to perform laboratory testing on a bridge alternative that counties can design and construct. This concept involves the fabrication of precast units composed of two steel beams connected by a thin concrete deck. The concrete deck thickness is limited so that the units can be fabricated at one location and then transported to the bridge site. The number of units required is obviously a function of the width of bridge desired. After the precast units have been connected, an additional concrete deck is placed. The concrete surface of the units is scarified so that the two layers of concrete are bonded together, thus providing the required deck thickness. Since this bridge replacement system is primarily intended for use on low-volume roads, the precast units could be constructed with new or used steel beams. The laboratory testing program consisted of a series of small-scale tests on different types of precast deck connections, “handling strength” tests of the precast units, a series of tests on the model bridge with only the precast portion of the deck in place, and a series of tests on the fully constructed model bridge. For the bridge model tested [ L = 9750 mm (32 ft), W = 6400 mm (21 ft)], five precast connectors gave the desired lateral load distribution; the addition of the cast-in-place deck significantly improved the load distribution characteristics of the bridge system. The units developed and tested result in a simple-span bridge for low-volume roads that is relatively easy to construct.

scholarly journals Optimization of low volume road pavement design and construction

2018 ◽  
Vol 64 (No. 2) ◽  
pp. 74-85 ◽  
Author(s):  
Hauser Jaroslav ◽  
Ševelová Lenka ◽  
Matula Radek ◽  
Zedník Petr
Keyword(s):  
The Czech Republic ◽  
Road Pavement ◽  
Low Volume Roads ◽  
Additional Costs ◽  
Low Volume ◽  
European Standards ◽  
Material Tests

Low volume roads in the Czech Republic are roads with lower traffic volume that primarily include forest and field roads, and they are an integral part of the Czech transport network. When building road pavements, we can use processes for surveying, designing, building and inspecting road constructions included in national and international, particularly European, standards. In addition, the roads are evaluated in terms of their environmental impacts, in order to maintain the quality of the environment. However, during the construction of road pavements decisions based on financial, time and other reasons are made. The decisions have impacts on the operation of roads and lead to other measures and additional costs of repairs and reconstructions. The article summarizes the authors’ research results from constructions of low volume road pavements and contains evaluations of laboratory and in situ material tests (soils, layers) of installed road pavements as well as evaluations of modelled laboratory and long-term monitored in situ structures.

Overview of radionuclide migration experiments in the HADES Underground Research Facility at Mol (Belgium)

Clay Minerals ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 153-166 ◽  
Author(s):  
M. Aertsens ◽  
N. Maes ◽  
L. Van Ravestyn ◽  
S. Brassinnes
Keyword(s):  
Diffusion Coefficients ◽  
Large Scale ◽  
Laboratory Experiments ◽  
Small Scale ◽  
Transport Parameters ◽  
Research Facility ◽  
Apparent Diffusion Coefficients ◽  
Apparent Diffusion ◽  
Clay Formation

AbstractIn situ migration experiments using different radiotracers have been performed in the HADES Underground Research Facility (URF), built at a depth of 225 m in the Boom Clay formation below the SCK–CEN nuclear site at Mol (Belgium). Small-scale experiments, mimicking laboratory experiments, were carried out with strongly retarded tracers (strontium, caesium, europium, americium and technetium). Contrary to europium, americium and technetium which are subjected to colloid mediated transport, the transport of strontium and caesium can be described by the classic diffusion retardation formalism. For these last two tracers, the transport parameters derived from the in situ experiments can be compared with the laboratory-derived values. For both tracers, the apparent diffusion coefficients measured in the in situ experiments agree well with the laboratory-derived values.In the large-scale experiments (of the order of metres) performed in the URF, non-retarded or slightly retarded tracers (HTO, iodide and H14CO3–) were used. The migration behaviour of these tracers was predicted based on models applied in performance assessment calculations (classic diffusion retardation) using migration parameter values measured in laboratory experiments. These blind predictions of large-scale experiments agree well in general with the experimental measurements. Fitting the experimental in situ data leads to apparent diffusion coefficients close to those determined by the laboratory experiments. The iodide and H14CO3– data were fitted with a simple analytical expression, and the HTO data were additionally fitted numerically with COMSOL multiphysics, leading to about the same optimal values.

scholarly journals Laboratory Measurements to Image Endobenthos and Bioturbation with a High-Frequency 3D Seismic Lander

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 508
Author(s):  
Inken Schulze ◽  
Dennis Wilken ◽  
Michael L. Zettler ◽  
Mayya Gogina ◽  
Mischa Schönke ◽  
...  
Keyword(s):  
Spatial Orientation ◽  
High Frequency ◽  
Laboratory Experiments ◽  
Small Scale ◽  
3D Seismic ◽  
Laboratory Measurements ◽  
Practical Application ◽  
Non Destructive ◽  
Seismic System

The presented 3D seismic system operates three transducers (130 kHz) from a stationary lander and allows non-destructive imaging of small-scale objects within the top decimeters of silty sediments, covering a surface area of 0.2 m2. In laboratory experiments, samples such as shells, stones, and gummy worms of varied sizes (down to approx. 1 cm diameter) could be located in the 3D seismic cube to a depth of more than 20 cm and differentiated by a reflected amplitude intensity and spatial orientation. In addition, simulated bioturbation structures could be imaged. In a practical application, the system allows to determine the abundance of endobenthos and its dynamic in muddy deposits in-situ and thus identify the intensity of local bioturbation.

SEM of non-coated hepatocellular cytoskeleton of perfused livers

1984 ◽  
Vol 42 ◽  
pp. 306-307
Author(s):  
S.W. French ◽  
N.C. Benson ◽  
C. Davis-Scibienski
Keyword(s):  
Ambient Temperature ◽  
Critical Point ◽  
Protease Inhibitors ◽  
Metal Deposition ◽  
Heat Damage ◽  
Detergent Extraction ◽  
Cytoskeletal Elements ◽  
Triton X ◽  
Excised Tissue

Previous SEM studies of liver cytoskeletal elements have encountered technical difficulties such as variable metal coating and heat damage which occurs during metal deposition. The majority of studies involving evaluation of the cell cytoskeleton have been limited to cells which could be isolated, maintained in culture as a monolayer and thus easily extracted. Detergent extraction of excised tissue by immersion has often been unsatisfactory beyond the depth of several cells. These disadvantages have been avoided in the present study. Whole C3H mouse livers were perfused in situ with 0.5% Triton X-100 in a modified Jahn's buffer including protease inhibitors. Perfusion was continued for 1 to 2 hours at ambient temperature. The liver was then perfused with a 2% buffered gluteraldehyde solution. Liver samples including spontaneous tumors were then maintained in buffered gluteraldehyde for 2 hours. Samples were processed for SEM and TEM using the modified thicarbohydrazide procedure of Malich and Wilson, cryofractured, and critical point dried (CPD). Some samples were mechanically fractured after CPD.

Study & Experimental Analysis of Pervious Concrete In Low Volume Roads

2018 ◽  
pp. 172-176
Author(s):  
Suraj Pinate ◽  
Hitesh Sonawane ◽  
Jayesh Barhate ◽  
Mayur Chaudhari ◽  
Utkarsha Dhok ◽  
...  
Keyword(s):  
Experimental Analysis ◽  
Pervious Concrete ◽  
Low Volume Roads ◽  
Low Volume

scholarly journals Upscaling THM modeling from small-scale to full-scale in-situ experiments in the Callovo-Oxfordian claystone

2021 ◽  
Vol 144 ◽  
pp. 104582
Author(s):  
D.M. Seyedi ◽  
C. Plúa ◽  
M. Vitel ◽  
G. Armand ◽  
J. Rutqvist ◽  
...  
Keyword(s):  
Full Scale ◽  
Small Scale ◽  
In Situ Experiments
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