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Project Details
STATUS

Completed

PROJECT NUMBER

ABC-UTC-2013-C2-ISU02

START DATE

01/01/16

END DATE

09/28/18

RESEARCH CENTERS InTrans, BEC, CMAT
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Alice Alipour

Structure and Infrastructure Engineer, BEC

About the research

Accelerated bridge construction (ABC) techniques are rapidly gaining acceptance as an alternative to conventional construction to reduce construction duration and minimize the impact of closures at the network level. There are different types of ABC and each technique has its limitations and speed of completion. The choice of using a specific ABC depends on a host of different factors including its applicability to specific bridge site, criticality of the bridge to the network, and availability of capital funds for its implementation. Some of these factors tend to have contradicting affects, as a faster ABC technique often entails higher investment levels; on the other hand, a faster technique for a bridge with high criticality to the network may result in large savings in user costs.

This report details the development of a mixed-integer programming model that provides a balanced portfolio of construction techniques on bridge sites over a prioritization process for bridges at the network level. For this purpose, while a network-level scheme is used to select the bridges for rapid replacement based on their criticalities to the network, a project-level scheme accordingly is conducted to optimize the choice of accelerated construction techniques. To account for the effects of different accelerated construction techniques, the costs associated with each replacement technique is calculated including direct costs from the actual replacement of bridges and indirect costs experienced by network users due to the bridge closure during the maintenance period.

Using the mixed-integer programming model, based on the investment budget, the new service performances of bridges, and the optimal accelerated construction techniques for different bridges, the bridge replacement strategy and the costs during the entire process are estimated, which could provide the decision-makers and stakeholders a detailed understanding of the prioritization process at both the network and project level.

Project Details
STATUS

Completed

PROJECT NUMBER

ABC-UTC-2013-C2-ISU03

START DATE

12/01/15

END DATE

12/28/18

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Behrouz Shafei

Structural Engineer, BEC

Co-Principal Investigator
Peter Taylor

Director, CP Tech Center

Co-Principal Investigator
Brent Phares

Bridge Research Engineer, BEC

Student Researcher(s)
Michael Dopko
Rizwan Karim
Shahin Hajilar

About the research

Accelerated bridge construction (ABC) is now being widely used by departments of transportation because of the reductions of traffic disruption, social cost, environmental impact, and lost time. ABC is also known to improve work zone safety, on-site constructability, and project completion time. One of the common techniques in ABC is using prefabricated bridge elements and systems (PBES). The bridge components are built outside of the construction area, transported on site, and then rapidly installed. Time lost due to concrete placement, curing in the construction zone, and formwork erection/removal is reduced. Another benefit to using prefabricated structural elements is improved quality control. Damaging effects due to weather are minimized because elements are built in a controlled environment. Considering the advantages of PBES, a number of research projects have been conducted on the prefabrication and installation of the main structural elements of the bridges.

However, there is a gap in the literature on how the long-term performance and durability concerns associated with the joints that connect already high-quality bridge elements may be addressed. One approach that has gained significant attention is to eliminate the joints through revised design strategies. While such strategies have been successfully developed for integral abutments used for ABC applications, no systematic study on removing the expansion joints between bridge girders has been found. To address this issue, the current research project investigated the use of a flexible link slab through a comprehensive set of experimental tests and numerical simulations. The outcome of this project was to provide the design guidelines and practical recommendations necessary to properly implement a link slab in the jointless bridges constructed with ABC and conventional techniques.

Project Details
STATUS

Completed

START DATE

01/01/18

END DATE

07/31/19

RESEARCH CENTERS InTrans, BEC, CMAT
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Katelyn Freeseman

Associate Director, BEC

Co-Principal Investigator
Jennifer Shane

Director, CMAT

About the research

Accelerated bridge construction (ABC) is a solution for upgrading substandard bridges that reduces construction and closure times and minimizes exposure of the traveling public and road workers to construction activities. To take full advantage of the benefits of ABC, agencies should decide which projects are appropriate for ABC, how to bid these projects given the unique attributes of ABC methods, and which procurement and project delivery methods to use.

The research team compiled information on decision matrices for identifying ABC projects, alternative delivery methods, and the procurement methods used for ABC projects, outlining bidding processes for projects that utilized ABC. Four ABC projects in three states (Georgia, Indiana, and Minnesota) were then investigated in detail. The research team reached out to personnel involved in the projects to discuss bid items, contracting methods, and lessons learned. The results of this effort are included in two separate reports and also in four standalone case study summaries.

The case studies suggest that ABC can be successfully implemented using any of the delivery methods explored in this study: design-build, design-bid-build, or construction manager/general contractor. Regardless of the project delivery method, communication and collaboration between the contractor and agency result in a better project outcome. Effective communication with the public is also important during ABC projects and can be done by either the agency or the contractor. When bids allow for flexibility, innovation is often incorporated into the project, which results in financial savings for the agency and/or time savings for the traveling public. After a project is completed, the agency can benefit from reviewing the lessons learned and successful aspects of the project and applying these to future projects.

Project Details
STATUS

Completed

START DATE

01/01/18

END DATE

04/30/20

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Brent Phares

Bridge Research Engineer, BEC

About the research

Bridge deck expansion joints allow for the movement of bridge decks exposed to thermal expansion and dynamic loading. These joints are often one of the first components of a bridge deck to fail, and there is a need for accelerated replacement options, especially in areas with high traffic volumes. Extensive research is being conducted on accelerated bridge construction (ABC) initiatives to reduce lane closure time. However, less attention has been devoted to accelerated repair and replacement of bridge deck expansion joints.

This project developed methods for the accelerated replacement of bridge deck expansion joints, beginning with a literature review. The combination of a stainless steel railing and ultra-high-performance concrete (UHPC) header with hydrodemolition was evaluated for its effectiveness as an accelerated option.

A life-cycle cost analysis with a sensitivity study compared the proposed replacement to current practices and two alternative methods. This analysis revealed that,for bridges with a life of greater than 50 years, the proposed replacement was the most cost-effective option.

The proposed replacement joint also underwent bonding, static, and fatigue testing. Hydrodemolition was also used in the replacement process of the testing. These tests indicated that the joint system utilizing hydrodemolition produces an excellent bond with the existing concrete. The static and fatigue testing revealed the joint system meets department of transportation (DOT)standards and would likely have a long service life.

Project Details
STATUS

In-Progress

START DATE

01/01/18

END DATE

02/29/20

RESEARCH CENTERS InTrans, BEC, CMAT
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Jennifer Shane

Director, CMAT

Co-Principal Investigator
Katelyn Freeseman

Associate Director, BEC

About the research

Accelerated bridge construction (ABC) is the solution of choice to upgrade substandard bridges, while maintaining traffic flow and optimizing safety through work zones. However, the perception of higher construction costs for ABC versus conventional construction continues in spite of numerous ABC projects having lower construction costs relative to conventional construction. This inaccurate perception and the fear of cost overruns are causing some bridge owners to be hesitant about using ABC technologies, especially those technologies related to bridge system moves that can provide the greatest benefit for safety and traffic flow impacts.

Whether to use ABC for a specific project needs to be decided at the project development stage. Research is needed to assist state DOTs in identifying successful delivery methods used for previously completed ABC projects to further encourage agencies to consider implementing accelerate construction practices for future project needs. This project focuses on case studies of delivery methods for ABC projects, as well as exploring potential advantageous alternatives when possible. Additionally, while the traditional contracting method for state DOTs is primarily unit price contracting, there are alternatives, including cost plus, lump sum, lump sum with guaranteed maximum price, and progressive lump sum with a guaranteed maximum price.  To date there has been little investigation into the use of these alternatives on ABC projects.

Project Details
STATUS

In-Progress

START DATE

01/01/18

END DATE

02/29/20

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC, CP Tech Center
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Behrouz Shafei

Structural Engineer, BEC

Co-Principal Investigator
Peter Taylor

Director, CP Tech Center

About the research

Accelerated Bridge Construction (ABC) is now widely considered by various transportation agencies to reduce traffic disruption, social cost, environmental impact, and lost time. ABC is also known to improve work zone safety, on-site constructability, and project completion time. One of the unique aspects of ABC is to exploit advanced construction materials to deliver high-quality prefabricated bridge elements and systems (PBES). Among such materials is ultra-high performance concrete (UHPC), which has received a growing attention for bridge applications, especially where superior strength and durability are critical. Although the high strength and durability of UHPC permits the production of thinner/lighter elements with a longer service life and less maintenance needs, use of UHPC in many of bridge projects is found cost prohibitive because commercially available/proprietary mixes can cost up to 20 times of conventional concrete mixes. To address this barrier, the main objective of the proposed research project is to develop and characterize economic, non-proprietary UHPC mixes made with the materials locally available. This will be achieved through a holistic set of laboratory experiments that will be primarily focused on the choice of fibers, which are known as the costliest ingredient of UHPC mixes.

Project Details
STATUS

In-Progress

START DATE

01/01/18

END DATE

02/29/20

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Katelyn Freeseman

Associate Director, BEC

Co-Principal Investigator
Brent Phares

Bridge Research Engineer, BEC

About the research

Accelerated bridge construction (ABC) has been implemented with greater frequency over the last decade, with successful projects geographically spread across the country. As these initial deployments of ABC methods age, it becomes necessary to inspect the structures for both maintenance decision making and for assurance of adequate service life performance. This data collection in the form of detailed inspection information allows for active management of the infrastructure and assessment of performance via key metrics. As such, it would be useful to broadly assess the performance of past ABC projects across the nation using consistent and effective inspection methods and metrics. This effort is further strengthened by the national presence of the ABC-UTC partner universities who are collaborating on this project.

Project Details
STATUS

Completed

START DATE

09/01/16

END DATE

10/22/18

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Terry Wipf

Faculty Affiliate

Co-Principal Investigator
Sri Sritharan

Faculty Affiliate

Student Researcher(s)
Ashley Ecklund

About the research

Many transportation organizations have embraced Accelerated Bridge Construction (ABC) to reduce both the traffic impacts and societal costs. One of the most common means to achieve ABC is to utilize prefabricated elements that are connected on site to construct a bridge. ABC will not be effective if the barrier requires cast-in-place construction. The purpose of this report is to present details of a precast barrier and two connection alternatives between the deck and precast barriers. In addition, a new connection between two adjacent prefabricated barriers was presented. All three connections were tested using full-scale precast barriers and a video summarizing the test can be found at https://youtu.be/up6sMEeqfaU.

One barrier-to-deck connection used inclined reinforcing bars with threaded ends that were connected to bar splicers embedded in the bridge deck. The other barrier-to-deck connection used U-shaped bars that were inserted into the barrier from the underside of the bridge deck overhang. Factors that were considered when designing the connections were minimal damage to deck, easy replacement of barrier, constructability, durability, and cost.

The barrier-to-barrier connection utilized headed reinforcement in the longitudinal and transverse directions. The connections were designed to meet TL-4 loads as per the Manual for Assessing Safety Hardware (MASH) and Load and Resistance Factor Design (LRFD) Bridge Design Specifications.

This report presents results from various tests and shows that all proposed connections are viable for accelerated construction of concrete barriers, although some refinement to the tested details will be needed.

Project Details
STATUS

Completed

START DATE

10/01/15

END DATE

02/22/18

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Brent Phares

Bridge Research Engineer, BEC

Co-Principal Investigator
Katelyn Freeseman

Associate Director, BEC

About the research

Accelerated Bridge Construction (ABC) has grown tremendously over the past several years, due in part to the maturation of new materials that have properties conducive to working in an ABC environment. In recent years, Caterpillar Inc. has developed several formulations of a cementitious material for building purposes called CEMPOSIT, which is a variation of macro-defectfree (MDF) concrete.

This material is unlike any cement-based material currently available and is much more closely related to various types of rubber—although with vastly different properties than rubber. These favorable properties include high strength (comparable to ultra-high-performance concrete), rapid early strength, extremely low permeability, and the ability to be extruded on-site to fit specific project needs.

The goal of this work was to assess important material characteristics of MDF concrete and to develop conceptual uses for the material with a specific focus on accelerated/robotic bridge construction. The findings from the material tests are presented, along with discussion of applicability for usage in the accelerated bridge construction field, in this report.

Project Details
STATUS

Completed

START DATE

10/01/17

END DATE

12/31/18

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

ABC-UTC

Researchers
Principal Investigator
Katelyn Freeseman

Associate Director, BEC

Co-Principal Investigator
Brent Phares

Bridge Research Engineer, BEC

About the research

The effectiveness of cast-in-place joints and other connections are of critical importance for ABC projects. While high strength materials are being used for these in-field connections, there is a general lack of existing research regarding inspection of joint quality and performance prior to opening to traffic. While these joints are intended to be constructed quickly, poor quality performance/construction will be detrimental to the equally important longevity of construction.

This report evaluates the capabilities of existing nondestructive testing technologies that could be used to determine bond and joint strength between pre-formed deck panels and the cast-in-place joint strips, and other ABC components of interest. The results of the information collection will be used to assess the feasibility of various techniques for further implementation in QA/QC efforts relating to ABC projects.

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