Flagstaff I-40 Asphalt Rubber Overlay Project: Nine Years of Success

2000 ◽  
Vol 1723 (1) ◽  
pp. 45-52 ◽  
Author(s):  
George B. Way
Keyword(s):  
Large Scale ◽  
Skid Resistance ◽  
Department Of Transportation ◽  
Reflective Cracking ◽  
Construction Time ◽  
Ground Tire Rubber ◽  
Cracked Concrete ◽  
Wet Process ◽  
Asphalt Rubber ◽  
Test Project

In 1990 the Arizona Department of Transportation designed and constructed a large-scale asphalt rubber (AR) test project in Flagstaff, Arizona, on the very heavily trafficked Interstate 40. The purpose of the test project was to determine whether a relatively thin overlay with AR could reduce reflective cracking. AR is a mixture of 80 percent hot paving-grade asphalt and 20 percent ground tire rubber. This mixture is also commonly referred to as the asphalt rubber wet process or McDonald process. The overlay project was built on top of a very badly cracked concrete pavement that was in need of reconstruction. The AR overlay has performed beyond original expectations. After 9 years of service the overlay is still virtually crack free, with good ride, virtually no rutting or maintenance, and good skid resistance. The benefits of using AR on this project represent about $18 million in construction savings and 4 years’ less construction time. Strategic Highway Research Program SPS-6 test sections built in conjunction with the project further illustrate the very good performance of AR. Results of this project have led to widespread use of AR hot mixes throughout Arizona. On the basis of this work over 3333 km (2,000 mi) of successfully performing AR pavements have been built since 1990.

Georgia’s Experience With Crumb Rubber in Hot-Mix Asphalt

1997 ◽  
Vol 1583 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Dan R. Brown ◽  
David Jared ◽  
Chris Jones ◽  
Don Watson
Keyword(s):  
Test Section ◽  
Hot Mix Asphalt ◽  
Crumb Rubber ◽  
Vacuum Extraction ◽  
Department Of Transportation ◽  
Reflective Cracking ◽  
Ground Tire Rubber ◽  
Asphalt Cement ◽  
Wet Process ◽  
Henry County

In 1991, the Georgia Department of Transportation (GDOT) began to evaluate the production and placement of crumb rubber hot-mix asphalt. The crumb rubber mix (CRM) used by GDOT was produced by adding ground tire rubber to hot-mix asphalt using the wet process. A test section of CRM was placed on I-75 in Henry County, just south of Atlanta, consisting of a surface mix containing 6 percent crumb rubber by weight of asphalt cement (AC). The test section was evaluated from 1991 to 1995. The test section indicated that the CRM became very brittle over time, as indicated by a large increase in viscosity and decrease in penetration, and by a large amount of transverse reflective cracking. Compared with the control mix, the CRM did not reduce rutting and was more than twice as expensive to place. In addition to the test section, two contract projects were initiated using CRM. These two projects indicated that CRM could be produced and placed using conventional equipment requiring only a few modifications. On-site blending units were used to combine the crumb rubber at a dosage rate of 16 percent by weight of AC. Pump and metering equipment was modified to accurately meter the stiff asphalt material, and correction factors were established for determining the AC content by vacuum extraction, since some of the rubber particles were retained in the aggregate portion of the sample.

Hot Mix Asphalt Rubber Applications in Virginia

1996 ◽  
Vol 1530 (1) ◽  
pp. 18-24 ◽  
Author(s):  
G. W. Maupin
Keyword(s):  
Department Of Transportation ◽  
Short Term ◽  
Ground Tire Rubber ◽  
Asphalt Rubber ◽  
Evaluation Time ◽  
Different Types ◽  
Virginia Department ◽  
Long Term Performance ◽  
Term Performance

Four test sections using asphalt rubber hot mix were placed in Virginia from 1990 to 1993. These installations were to familiarize contractors and Virginia Department of Transportation personnel with the construction process and compare the performance of different types of mixes containing ground tire rubber. The MacDonald and Rouse wet processes were used successfully. Dense graded surface mixes, a gap-graded surface mix, and a base mix were manufactured. A stress-absorbing membrane interlayer was also used on one project in an attempt to deter or eliminate various types of cracking. The asphalt rubber mixes have performed as well as the conventional mixes over the short term. More evaluation time is needed to determine if long-term performance of the asphalt rubber mixes is superior to conventional mixes. The asphalt rubber mixes cost 64 to 102 percent more than conventional mixes. This cost would probably decrease if substantial quantities were placed.

scholarly journals Using a Cable-Driven Parallel Robot with Applications in 3D Concrete Printing

2021 ◽  
Vol 11 (2) ◽  
pp. 563
Author(s):  
Tuong Phuoc Tho ◽  
Nguyen Truong Thinh
Keyword(s):  
3D Printing ◽  
Large Scale ◽  
Trust Region ◽  
Parallel Robot ◽  
Inverse Kinematic ◽  
Programming Algorithm ◽  
Construction Time ◽  
Inverse Kinematic Problem ◽  
Robot Configuration ◽  
Printing Method

In construction, a large-scale 3D printing method for construction is used to build houses quickly, based on Computerized Aid Design. Currently, the construction industry is beginning to apply quite a lot of 3D printing technologies to create buildings that require a quick construction time and complex structures that classical methods cannot implement. In this paper, a Cable-Driven Parallel Robot (CDPR) is described for the 3D printing of concrete for building a house. The CDPR structures are designed to be suitable for 3D printing in a large workspace. A linear programming algorithm was used to quickly calculate the inverse kinematic problem with the force equilibrium condition for the moving platform; this method is suitable for the flexible configuration of a CDPR corresponding to the various spaces. Cable sagging was also analyzed by the Trust-Region-Dogleg algorithm to increase the accuracy of the inverse kinematic problem for controlling the robot to perform basic trajectory interpolation movements. The paper also covers the design and analysis of a concrete extruder for the 3D printing method. The analytical results are experimented with based on a prototype of the CDPR to evaluate the work ability and suitability of this design. The results show that this design is suitable for 3D printing in construction, with high precision and a stable trajectory printing. The robot configuration can be easily adjusted and calculated to suit the construction space, while maintaining rigidity as well as an adequate operating space. The actuators are compact, easy to disassemble and move, and capable of accommodating a wide variety of dimensions.

Cost-Effectiveness of Paving Fabrics Used to Control Reflective Cracking

2000 ◽  
Vol 1730 (1) ◽  
pp. 139-149 ◽  
Author(s):  
William G. Buttlar ◽  
Diyar Bozkurt ◽  
Barry J. Dempsey
Keyword(s):  
Life Cycle ◽  
Cost Effectiveness ◽  
Department Of Transportation ◽  
Reflective Cracking ◽  
Crack Control ◽  
Condition Rating ◽  
System A ◽  
Rigid Pavements ◽  
The Cost ◽  
And Control

The Illinois Department of Transportation (IDOT) spends $2 million annually on reflective crack control treatments; however, the cost-effectiveness of these treatments had not been reliably determined. A recent study evaluated the cost-effectiveness of IDOT reflective crack control System A, which consists of a nonwoven polypropylene paving fabric, placed either in strips longitudinally over lane-widening joints or over the entire pavement (area treatment). The study was limited to projects constructed originally as rigid pavements and subsequently rehabilitated with one or more bituminous overlays. Performance of 52 projects across Illinois was assessed through crack mapping and from distress and serviceability data in IDOT’s condition rating survey database. Comparisons of measured reflective cracking in treated and control sections revealed that System A retarded longitudinal reflective widening crack development, but it did not significantly retard transverse reflective cracking, which agrees with earlier studies. However, both strip and area applications of these fabric treatments appeared to improve overall pavement serviceability, and they were estimated to increase rehabilitation life spans by 1.1 and 3.6 years, respectively. Reduction in life-cycle costs was estimated to be 4.4 and 6.2 percent when placed in medium and large quantities, respectively, and to be at a break-even level for small quantities. However, life-cycle benefits were found to be statistically insignificant. Limited permeability testing of field cores taken on severely distressed transverse joints suggested that waterproofing benefits could exist even after crack reflection. This was consistent with the observation that, although serviceability was generally improved with area treatment, crack reflection was not retarded relative to untreated areas.

scholarly journals Evaluation of Various Perimeter Barrier Products

2021 ◽  
Author(s):  
Rabin Bhattarai ◽  
◽  
Yufan Zhang ◽  
Jacob Wood ◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Sediment Concentration ◽  
Department Of Transportation ◽  
Vegetative Cover ◽  
Buffer Strip ◽  
Erosion Rates ◽  
Sediment Removal ◽  
Loam Soil ◽  
A Site ◽  
Large Scale Tests

Construction activities entail substantial disturbance of topsoil and vegetative cover. As a result, stormwater runoff and erosion rates are increased significantly. If the soil erosion and subsequently generated sediment are not contained within the site, they would have a negative off-site impact as well as a detrimental influence on the receiving water body. In this study, replicable large-scale tests were used to analyze the ability of products to prevent sediment from exiting the perimeter of a site via sheet flow. The goal of these tests was to compare products to examine how well they retain sediment and how much ponding occurs upstream, as well as other criteria of interest to the Illinois Department of Transportation. The products analyzed were silt fence, woven monofilament geotextile, Filtrexx Siltsoxx, ERTEC ProWattle, triangular silt dike, sediment log, coconut coir log, Siltworm, GeoRidge, straw wattles, and Terra-Tube. Joint tests and vegetated buffer strip tests were also conducted. The duration of each test was 30 minutes, and 116 pounds of clay-loam soil were mixed with water in a 300 gallon tank. The solution was continuously mixed throughout the test. The sediment-water slurry was uniformly discharged over an 8 ft by 20 ft impervious 3:1 slope. The bottom of the slope had a permeable zone (8 ft by 8 ft) constructed from the same soil used in the mixing. The product was installed near the center of this zone. Water samples were collected at 5 minute intervals upstream and downstream of the product. These samples were analyzed for total sediment concentration to determine the effectiveness of each product. The performance of each product was evaluated in terms of sediment removal, ponding, ease of installation, and sustainability.

High-Speed Noncontact Profiling of Pavement Surface Texture and Its Significance

1986 ◽  
Vol 108 (3) ◽  
pp. 455-461
Author(s):  
J. C. Wambold ◽  
J. J. Henry
Keyword(s):  
Surface Texture ◽  
High Speed ◽  
Large Scale ◽  
Vision System ◽  
Small Scale ◽  
Skid Resistance ◽  
Texture Measurement ◽  
Pavement Surface ◽  
Texture Characteristics ◽  
Regression Techniques

It is generally agreed that the friction between a tire and a wet pavement (skid resistance) is controlled by the surface texture characteristics. Therefore, by measuring the relevant parameters describing texture, or by measuring a physical process dependent on texture, regression techniques can be used to relate skid resistance to the chosen texture parameter or process. Two scales of texture are of particular importance: microtexture (small-scale asperities) and macrotexture (large-scale asperities). This paper describes work performed to: (1) review candidate macrotexture and microtexture measurement methods that can be made at highway speeds (at or about 64 km/h [40 mph]), which are presently used or have potential for use in pavement texture measurement; (2) design and build a prototype of the most promising method; and (3) evaluate the effects of pavement surface texture on skid resistance. A prototype noncontact vision system that makes texture measurements at highway speeds was developed, and several improvements were made to upgrade the system to provide an improved prototype. Both hardware and software enhancements have yielded a texture measurement system that can obtain pavement macrotexture data in a fast, efficient, and reliable way.

scholarly journals Accelerated Laboratory Testing for Reflective Cracking

2021 ◽  
Vol 10 (1) ◽  
pp. 34-49
Author(s):  
Mihai Gabriel Lobază
Keyword(s):  
Laboratory Test ◽  
Composite Structure ◽  
Laboratory Testing ◽  
Lower Layer ◽  
Concrete Slab ◽  
Asphalt Pavement ◽  
Reflective Cracking ◽  
Cracked Concrete ◽  
Traffic Loads ◽  
Number Of Cycles

Abstract One of the most used methods of rehabilitation of road structures is the laying of a protective asphalt layer over a degraded concrete. The main problem of this solution is the reflective cracking, more precisely the transmission of the existing cracks in the lower layer in the asphalt pavement. The method presented in this article involves an accelerated laboratory test on specimens composed of a pre-cracked concrete slab over which an asphalt slab is glued, subjected to equivalent traffic loads. This test allows the observation of the crack propagation from the lower layer to the upper layer, until it yields, through parameters such as deformed specimen, opening and length of the crack in asphalt, but also the opening of the existing crack in concrete, relative to the number of cycles. By relating these parameters, important conclusions can be drawn about the behavior of the composite structure at reflective cracking, being able to choose the optimal recipe of the protective asphalt layer.

scholarly journals PARAMTR - Enhanced generative design tools for prefabricating large-scale residential developments

2021 ◽  
Author(s):  
◽  
Joshua Joe
Keyword(s):  
Large Scale ◽  
Design Tool ◽  
Design Tools ◽  
Generative Design ◽  
Construction Costs ◽  
Construction Time ◽  
Residential Developments ◽  
And Performance ◽  
Residential Projects ◽  
Aec Industry

<p><b>Designers are encountering greater issues with residential projects, which are increasing in complexity, scale, and performance requirements. Despite significant advancements in technology and the AEC industry, large-scale residential developments are still designed and built at scale as if they were singular projects. Variable and increased construction time, cost, and material waste at scale are all issues with existing design and construction methodologies for construction at scale. Prefabrication and generative design tools have the potential to significantly reduce these issues.</b></p> <p>This paper investigates how collaborative, human-generative design tools can optimise building performance and make prefabricated housing at scale feasible, whilst still encouraging design variance. In this context, collaborative human-generative tools refer to a partially algorithmic design tool that facilitates an open-box approach to design. Using a mixture of research-based design and design-based research, a new tool (PARAMTR) was created to improve feasibility whilst reducing time, complexity, and cost of designing and building residential projects using prefabrication at scale. </p> <p>The research demonstrates eight unique designs produced using the new human-generative tool. Despite their individuality, these designs have 8-10 times fewer unique components when compared to existing residential projects. Designs produced using PARAMTR could reduce construction/design time by up to 50%, reduce construction costs by up to 26% and share no design commonality, enabling unique designs across an entire development. This research paper could therefore fundamentally change how the AEC industry builds at scale, using algorithms and human-generative design tools.</p>

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