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 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.

Strength and Behavior of Materials for Low-Volume Roads as Affected by Moisture and Density

2003 ◽  
Vol 1819 (1) ◽  
pp. 104-109 ◽  
Author(s):  
P. Paige-Green
Keyword(s):  
Quality Assurance ◽  
Southern Africa ◽  
Laboratory Testing ◽  
Simple Technique ◽  
Material Strength ◽  
Pavement Materials ◽  
Moisture Contents ◽  
Low Volume Roads ◽  
Low Volume ◽  
And Behavior

The relationships among strength, moisture, and density in pavement subgrades and layerworks are well known, but they have particular significance in low-volume roads. In these roads, the specified density is frequently not achieved (quality assurance testing tends to be reduced), and moisture fluctuations are more severe with greater consequences. Traditional studies of the material strength for these roads in southern Africa are based almost entirely on the California bearing ratio (CBR), a test with inherent problems. The test is routinely carried out to identify whether the materials under consideration have the required soaked strengths (typically CBRs of 80% or 45% for bases of different standards) at the design compaction density. Studies of the CBR at different moisture contents and densities should be carried out to identify the implications of variations in these properties on the behavior of pavement materials. A simple technique to be carried out during conventional laboratory testing was developed. Aspects pertaining to this type of study were evaluated, and the findings were related to low-volume road behavior.

Laboratory Testing of Stress-Laminated Wood Decks on Steel Beams

1997 ◽  
Vol 1575 (1) ◽  
pp. 47-52
Author(s):  
Barry Dickson ◽  
Hota GangaRao ◽  
Vijith Vijayachandran
Keyword(s):  
Load Distribution ◽  
Laboratory Testing ◽  
Static Load ◽  
Theoretical Calculations ◽  
Construction Cost ◽  
Transverse Load ◽  
Steel Beams ◽  
Composite Action ◽  
Static Testing ◽  
Load Tests

Four different stress-laminated wood decks were laboratory-tested to measure composite action between deck and steel beams, transverse load distribution, performance of connectors, and deck construction cost. The models were subjected to cyclic loading varying from 9 to 89 kN. Static load tests were conducted after every 100,000 cycles. During static testing, strains and deflections in the beams were measured at 22, 44, 67, and 89 kN. The loss of tension in the connectors was also monitored after every 100,000 cycles. The readings were used to compare the composite action, load distribution, and tension loss in connectors. Load distribution values were verified with theoretical calculations.

Low-Volume Road Bridge Alternative

2000 ◽  
Vol 1696 (1) ◽  
pp. 178-186
Author(s):  
B. M. Phares ◽  
F. W. Klaiber ◽  
T. J. Wipf
Keyword(s):  
Finite Element ◽  
Design Methodology ◽  
Structural Engineering ◽  
Element Model ◽  
Analytical Investigation ◽  
Bridge Engineering ◽  
Scale Model ◽  
Small Scale ◽  
Steel Beams ◽  
Concrete Deck

Recent reports indicate that a significant number of the nation’s bridges are either structurally deficient or functionally obsolete. A large number of these bridges are on the secondary road system and fall under the jurisdiction of county engineers with limited budgets and engineering staff. In response to this problem, a bridge replacement system was developed for simple span bridges with minimal to no skew that county engineers can design and build with limited resources. The bridge system involves fabrication of precast units consisting of two steel beams connected with a thin reinforced concrete deck. The precast deck thickness is limited to reduce the weight of the units so that they can be fabricated at one site and then easily transported to the bridge site. Multiple units are then connected on site to give the desired width of bridge, after which a reinforced cast-in-place concrete deck is placed over the entire bridge. Development of the design methodology for the steel beam precast unit bridge consisted of four phases. During the initial phase, small-scale bridge components and a full-scale model bridge were constructed and tested in the Iowa State University Structural Engineering Laboratory. These specimens were tested under a variety of loading configurations under service and ultimate loads. After completion of the laboratory testing, finite-element models of the laboratory bridge were developed and validated with data collected during the first phase. The validated finite-element model was then used to extrapolate analyses of common bridge configurations. The results of the analytical investigation were then combined with classic bridge engineering principles into a design methodology that is easy to use and understand. Although it is not discussed in detail, a demonstration project in which this concept was used has recently been completed and tested.

Rural Track Paths on Low-Volume Roads in Austria

2019 ◽  
Vol 2673 (12) ◽  
pp. 863-873
Author(s):  
Wolfgang Haslehner
Keyword(s):  
Road Network ◽  
Concrete Surface ◽  
Public Authorities ◽  
Design Guideline ◽  
Rural Road ◽  
Low Volume Roads ◽  
Load Carrying ◽  
Low Volume ◽  
Special Circumstances ◽  
The Impact

The rural road network in Austria consists of all roads that are neither federal nor provincial roads and serve the purpose of enabling access to the rural area. This low-volume road network includes all municipal roads, farm roads, and forest roads. The total length of these roads amounts to approximately 160,000 km or 80% of the total Austrian road network. The responsibility for construction and maintenance of this rural road network in Austria is split between private persons and public authorities. Within these special circumstances a new technical design guideline for rural track paths has been elaborated in Austria. During this elaboration the experiences and know-how from Germany and Switzerland have been analyzed and taken into consideration. The main part of the paper deals with this new design guideline and shows an innovative way to handle activities in construction and maintenance of low-volume roads realized as single-lane rural track paths. These track paths consist of two load-carrying tracks constructed of asphalt, concrete, surface treatment, or block pavers. The obvious advantages of this tracked paving approach are to reduce the impact of impervious surface types and the impact on the environment. What makes this guideline unique is the fact that it is the first of its kind in Austria to encompass all aspects of planning, design, practical construction, and implementation of rural track paths on low-volume roads.

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

Analysis of the Relationship Between Rail Seat Load Distribution and Rail Seat Deterioration in Concrete Crossties

2014 ◽  
Author(s):  
Matthew Greve ◽  
Marcus S. Dersch ◽  
J. Riley Edwards ◽  
Christopher P. L. Barkan ◽  
Jose Mediavilla ◽  
...  
Keyword(s):  
Load Distribution ◽  
Failure Modes ◽  
Failure Mechanisms ◽  
Past Research ◽  
Concrete Surface ◽  
Hydraulic Pressure ◽  
Valuable Insight ◽  
Increased Risk ◽  
Abrasive Erosion ◽  
Field Experimentation

One of the most common failure modes of concrete crossties in North America is the degradation of the concrete surface at the crosstie rail seat, also known as rail seat deterioration (RSD). Loss of material beneath the rail can lead to wide gauge, rail cant deficiency, and an increased risk of rail rollover. Previous research conducted at the University of Illinois at Urbana-Champaign (UIUC) has identified five primary failure mechanisms: abrasion, crushing, freeze-thaw damage, hydro-abrasive erosion, and hydraulic pressure cracking. The magnitude and distribution of load applied to the rail seat affects four of these five mechanisms; therefore, it is important to understand the characteristics of the rail seat load distribution to effectively address RSD. As part of a larger study funded by the Federal Railroad Administration (FRA) aimed at improving concrete crossties and fastening systems, researchers at UIUC are attempting to characterize the loading environment at the rail seat using matrix-based tactile surface sensors (MBTSS). This instrumentation technology has been implemented in both laboratory and field experimentation, and has provided valuable insight into the distribution of a single load over consecutive crossties. A review of past research into RSD characteristics and failure mechanisms has been conducted to integrate data from field experimentation with existing knowledge, to further explore the role of the rail seat load distribution on RSD. The knowledge gained from this experimentation will be integrated with associated research conducted at UIUC to form the framework for a mechanistic design approach for concrete crossties and fastening systems.

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