Quality Assurance for Caltrans Bridge Shear Retrofit Projects

A quality assurance (QA) process is proposed to prevent the possibility of legal issues for a multibridge retrofit project recently conducted by the California Department of Transportation (Caltrans) to increase the horizontal shear resistance of decks. Providing a solution requires determining an appropriate number of samples with the corresponding sampling scheme to ensure 95% compliance with the specification requirements. The determination of the appropriate sample size must recognize the practical considerations of cost, time, statistical simulation results, and the binomial distribution theory. It is not uncommon for many agencies to base quality assurance on just three samples. Using a binomial distribution, a discussion is also presented why it is not appropriate to take this limited number of samples for quality assurance. With the selection of sample size for each bridge, a representative sampling scheme that is random and unbiased was developed using the concept of uniform design as sampling strategy. The recommended acceptance criteria are specified based on the hypothesis testing results with the normal approximation of a binomial distribution

Analyses of the Response of Pavements Containing Ceramic Plugs for Vehicle Guidance

In studies undertaken by staff of the PATH Program concerned with automatic vehicle control (AVC) ceramic sensors (magnets) have been placed at or near the surface of both asphalt concrete (AC) and portland cement concrete (PCC) pavements. Thus far sensors have been installed at three locations: 1) AC pavement at the Richmond Field Station (RFS); 2) AC and PCC pavement on Interstate 15 in San Diego, CA; and 3) AC and PCC pavement on Interstate 80 near Donner Summit, CA. The installations at Donner Summit have been used for the guidance of snow plows during the winter months. With increased interest in dedicated truck lanes for goods movement where vehicle guidance could have significant economic influence (1,2,3,4) as well as for uses like those at Donner Summit noted above, the question arises relative to the long-term effects of these sensors on the satisfactory performance of the pavement/sensor system. Potential reductions in pavement and/or sensor performance could result from interactions between the vehicle, the sensor and the pavement as well as from environmental effects because of the embedment of a material with dissimilar thermal characteristics to that of the pavement

Quality Assurance for Caltrans Bridge Shear Retrofit Projects

A quality assurance (QA) process is proposed to prevent the possibility of legal issues for a multibridge retrofit project recently conducted by the California Department of Transportation (Caltrans) to increase the horizontal shear resistance of decks. Providing a solution requires determining an appropriate number of samples with the corresponding sampling scheme to ensure 95% compliance with the specification requirements. The determination of the appropriate sample size must recognize the practical considerations of cost, time, statistical simulation results, and the binomial distribution theory. It is not uncommon for many agencies to base quality assurance on just three samples. Using a binomial distribution, a discussion is also presented why it is not appropriate to take this limited number of samples for quality assurance. With the selection of sample size for each bridge, a representative sampling scheme that is random and unbiased was developed using the concept of uniform design as sampling strategy. The recommended acceptance criteria are specified based on the hypothesis testing results with the normal approximation of a binomial distribution

Dynamic Finite-Element Analysis of Jointed Concrete Pavements

A new dynamic finite-element computer program, DYNA-SLAB, for the analysis of jointed concrete pavements subjected to moving transient loads is presented. The dynamic solution is formulated in both the time and the frequency domains. The structural model for the slab system is the one used in the static computer program ILLI-SLAB. The foundation support is represented by either a damped Winkler model with uniformly distributed frequency-dependent springs and dashpots or a system of semi-infinite horizontal layers resting on a rigid base or a semi-infinite half-space. An important contribution from the study is a new analytical method for determining the stiffness and damping coefficients to be used in the Winkler foundation model. The accuracy of DYNA-SLAB has been verified by comparing the results produced by the program with those from theoretical closed-form solutions and from a powerful dynamic soil-structure interaction computer program called SASSI as well as with field data. The analytical results indicate that dynamic analysis is generally not needed for the design of rigid pavements and that it usually leads to decreased pavement response. Thus, it appears that a quasistatic analysis is sufficient and that the results from this type of analysis will generally be conservative, provided that the wheel loads used in the analysis have been adjusted for the effects of vehicle velocity, truck suspension characteristics, and pavement roughness

Dynamic Finite-Element Analysis of Jointed Concrete Pavements

A new dynamic finite-element computer program, DYNA-SLAB, for the analysis of jointed concrete pavements subjected to moving transient loads is presented. The dynamic solution is formulated in both the time and the frequency domains. The structural model for the slab system is the one used in the static computer program ILLI-SLAB. The foundation support is represented by either a damped Winkler model with uniformly distributed frequency-dependent springs and dashpots or a system of semi-infinite horizontal layers resting on a rigid base or a semi-infinite half-space. An important contribution from the study is a new analytical method for determining the stiffness and damping coefficients to be used in the Winkler foundation model. The accuracy of DYNA-SLAB has been verified by comparing the results produced by the program with those from theoretical closed-form solutions and from a powerful dynamic soil-structure interaction computer program called SASSI as well as with field data. The analytical results indicate that dynamic analysis is generally not needed for the design of rigid pavements and that it usually leads to decreased pavement response. Thus, it appears that a quasistatic analysis is sufficient and that the results from this type of analysis will generally be conservative, provided that the wheel loads used in the analysis have been adjusted for the effects of vehicle velocity, truck suspension characteristics, and pavement roughness

Construction and Traffic Analysis of Interstate 15 (Devore II) Concrete Pavement Reconstruction Project

The California Department of Transportation (Caltrans) replaced about 5 kilometers (total 20 lane-kilometers) of concrete pavement on Interstate 15 in Devore, California. The I-15 Devore II rehabilitation project was completed in six weekend closures with around-the-clock construction in early 2007, with partial or full closures of one direction of the freeway. A traffic monitoring study with surveillance systems was conducted to validate the project’s transportation management plan (TMP), and to utilize the collected data for a better understanding of traffic flow characteristics at the work zone and traffic demand/capacity changes on highly trafficked urban highway projects. In addition, a construction productivity monitoring study was conducted to analyze productivity for the four construction activities; demolition, milling, Asphalt Concrete (AC) paving, and Portland cement concrete (PCC) paving. The traffic study showed that the overall impact of the work zone closure on the traveling public was manageable in most closures due to the efficient implementation of the project TMP. For example, a reduction of up to 70 percent of traffic demand during peak hours was achieved in on e weekend closure. Different lane closure configurations yielded different work zone capacity values. The construction study investigates productivity progress by comparison of gross rate, operating rate, and truckload for each construction activity. This study can help guide state agencies and transportation engineers in establishing adequate TMPs and construction stage plans to improve mobility and productivity on future highway rehabilitation project

Friction Testing of Pavement Preservation Treatments: Friction Measurements on Fog Seal Trials Using Six Rejuvenators, State Route KER58

This technical memorandum describes an investigation (1) to measure the change in pavement surface friction at three hours and at three days after application of six rejuvenators as fog seals and (2) to compare friction values obtained using the California Skid Tester (CST), the British Pendulum Tester (BPT), and the Dynamic Friction Tester (DFT). Statistical correlations among the CST, BPN, and DFT are presented

Construction and Traffic Analysis of Interstate 15 (Devore II) Concrete Pavement Reconstruction Project

The California Department of Transportation (Caltrans) replaced about 5 kilometers (total 20 lane-kilometers) of concrete pavement on Interstate 15 in Devore, California. The I-15 Devore II rehabilitation project was completed in six weekend closures with around-the-clock construction in early 2007, with partial or full closures of one direction of the freeway. A traffic monitoring study with surveillance systems was conducted to validate the project’s transportation management plan (TMP), and to utilize the collected data for a better understanding of traffic flow characteristics at the work zone and traffic demand/capacity changes on highly trafficked urban highway projects. In addition, a construction productivity monitoring study was conducted to analyze productivity for the four construction activities; demolition, milling, Asphalt Concrete (AC) paving, and Portland cement concrete (PCC) paving. The traffic study showed that the overall impact of the work zone closure on the traveling public was manageable in most closures due to the efficient implementation of the project TMP. For example, a reduction of up to 70 percent of traffic demand during peak hours was achieved in on e weekend closure. Different lane closure configurations yielded different work zone capacity values. The construction study investigates productivity progress by comparison of gross rate, operating rate, and truckload for each construction activity. This study can help guide state agencies and transportation engineers in establishing adequate TMPs and construction stage plans to improve mobility and productivity on future highway rehabilitation projectsUCPRC-RR-2008-05, Civil Engineering

Development of Hot Mix Asphalt Pavement Performance Properties for Long-life Pavement Design: Caltrans District 2, Interstate 5, Red Bluff, California

In the period 2012 to 2014, Caltrans designed and built three long-life asphalt pavement (LLAP) rehabilitation projects. Two projects were in District 2 on Interstate 5 and one was in District 4 on Interstate 80. This technical memorandum describes the processes by which performance-related test criteria were developed for a pavement section on the project on Interstate 5 just north of Red Bluff, California. The pavement section was designed and constructed as an LLAP section consisting of the following pavement components: A hot mix asphalt (HMA) surface course containing a polymer-modified asphalt (PG 64-28PM), 15 percent reclaimed asphalt pavement (RAP), and a representative aggregate from the Red Bluff area treated with 1.2 percent lime (marinated). An HMA intermediate course containing a conventional asphalt binder (PG 64-10) and the same lime-treated aggregate as the surface course plus 25 percent RAP. An HMA rich bottom layer containing conventional asphalt binder (PG 64-10) and the same lime-treated aggregate as the intermediate course, and containing 15 percent RAP Representative materials were obtained by Caltrans District 2 from the Red Bluff area for the testing to develop the design and performance-related specifications for this project. During the testing of these materials some changes were made in the mix specifications regarding the asphalt binder grade and the inclusion of RAP in the surface mix and in the rich bottom mix; these are described in this memorandum. Caltrans headquarters staff from the Office of Flexible Pavement (formerly the Division of Flexible Pavement) designed the structural pavement sections using material parameters developed from AASHTO T 320 shear testing and AASHTO T 321 fatigue and stiffness testing results. To properly establish testing protocols and parameters, it was also necessary to investigate traffic loading and environmental factors as part of the study. This testing produced the performance-related testing criteria that were included in the project specifications and bid documents. In addition to the AASHTO T 320 and T 321 results used for design and performance-related specifications, results from AASHTO T 324 Hamburg Wheel-Track Testing (HWTT) were required in the performance-based specifications as a consideration for moisture sensitivity. The HWTT results were not used in the design process