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International Concrete Abstracts Portal

Showing 1-5 of 15 Abstracts search results

Document: 

SP340

Date: 

April 30, 2020

Author(s):

Andrzej S. Nowak, Hani Nassif, Victor Aguilar

Publication:

Symposium Papers

Volume:

340

Abstract:

Professor Dennis Mertz passed away after a prolonged battle with cancer. He spent a large portion of his professional career working on advancing of the state-of-the-art of bridge engineering. He was a great friend and colleague to many at ACI and ASCE. Joint ACI-ASCE Committee 343, joined with ACI Committees 342 and 348, sponsored four sessions to honor his contributions and achievements in concrete bridge design and evaluation. These sessions highlighted the important work and collaborative efforts that Dr. Mertz had with others at ACI and ASCE on various topics. These sessions also combined the efforts among ACI and ASCE researchers and practitioners in addressing various topics related to the design and evaluation of concrete bridges. The scope and outcome of the sessions are relevant to ACI’s mission. They raise awareness on established design methodologies applied for various limit states covering topics related flexure, shear, fatigue, torsion, etc. They address problems related to emerging design and evaluation approaches and recent development in design practices, code standards, and related applications. The Symposium Publication (SP) is expected to be an important reference in relation to design philosophies and evaluation methods of new and existing concrete bridges and structures.

DOI:

10.14359/51725848


Document: 

SP-340-07

Date: 

April 1, 2020

Author(s):

Sary A. Malak and Neven Krstulovic-Opara

Publication:

Symposium Papers

Volume:

340

Abstract:

This paper provides an overview of simplified methods for dynamic blast analysis of structural members. The presented approach focuses on the use of a general simplified non-linear single degree of freedom dynamic model commonly used for typical flexural members such as slabs, beams or columns. The presented approach also allows modeling of members retrofitted against blast loading using fiber composites. The fiber composites considered in this paper include conventional Steel Fiber Reinforced Composites (FRC) as well as High Performance Fiber Composites (HPFRC). HPFRC’s include Short Steel Slurry Infiltrated Concrete (SIFCON), Long Continuous Slurry Infiltrated Steel Fibers Mat Concrete (SIMCON), and Fiber Reinforced Polymers (FRP). The model identifies different material parameters that affect the response of the structure. The effect of the material properties on the composite response is discussed within the framework of the existing blast-resistance guidelines and standards. Different retrofit techniques for existing concrete structures using fiber reinforced composites and the effect of varying the composite material properties on the response is presented. Final conclusions and recommendations are provided in terms of composite material’s properties, modeling performance and response. Specific limitations on their use is also discussed.

DOI:

10.14359/51725809


Document: 

SP-340-12

Date: 

April 1, 2020

Author(s):

Piotr Moncarz, Tea Visnjic, and Peter H. Feenstra

Publication:

Symposium Papers

Volume:

340

Abstract:

This paper presents a numerical study of novel configurations in reinforced concrete wall systems that exhibit large structural ductility and increased post-ultimate strength, leading to potentially better performing structures under large and sustained loads. A Gravity-Based Structure (GBS) under extreme ice loading is used as use-case to investigate various scenarios to increase post-ultimate ductility. It is shown that the largest increase in the out-of-plane toughness of the exterior reinforced concrete walls is gained using post-tensioned tendons and mild “core” steel placed at the center of the exterior wall cross section. These structural features show promise in improving the global post-ultimate behavior, which would make them desirable to use in structures that are deployed in locations where extreme ice feature impacts pose a foreseeable risk and where designing the structure to remain elastic under ice impact may not be economically feasible. Lessons-learned from the GBS evaluation can also be applied to various reinforced concrete structures.

DOI:

10.14359/51725814


Document: 

SP-340-08

Date: 

April 1, 2020

Author(s):

Tevfik Terzioglu, Dongqi Jiang, Mary Beth D. Hueste, and John B. Mander

Publication:

Symposium Papers

Volume:

340

Abstract:

A new bridge system was recently developed for short span bridges in low clearance areas. This system uses the same concept as spread box beam bridges in which standard TxDOT precast prestressed slab beams are spaced apart. The deck is composed of stay-in-place precast concrete panels spanning between beams with a cast-in-place reinforced concrete deck. This paper presents a comprehensive approach for the investigation and development of this alternative spread slab beam bridge system including design, construction, field testing, modeling, and derivation of live load distribution factors (LLDFs). A parametric design study was conducted to evaluate the potential bridge spans when considering the four standard TxDOT slab beam types, a range of beam spacings, and potential bridge widths. One of the challenging geometries with widely spaced slab beams was constructed at full-scale to assess constructability and in-service behavior. The full-scale test bridge and a recently constructed on-system bridge with more closely spaced slab beams were tested under static and dynamic truck loads to obtain important insight into their structural performance and live load distribution behavior, while also providing data to guide analytical and computational modeling studies. Finite element models were developed to investigate an array of possible bridge geometries and determine the effect of key parameters on the load sharing behavior. Based on the research findings, it was concluded that spread slab beam bridges with a topped panelized deck provide a viable construction method for short-span bridges. For both tested bridges, the desired performance was achieved for in-service loading. Experimental and computational LLDFs were evaluated, and LLDF equations for spread box beams were reviewed for applicability to spread slab beam bridges. The AASHTO LRFD spread box beam LLDFs range from being unconservative to very conservative. Unique moment and shear LLDFs were developed for use in design of spread slab beam bridges.

DOI:

10.14359/51725810


Document: 

SP-340-04

Date: 

April 1, 2020

Author(s):

Michael J. Chajes, Harry W. Shenton III, Hadi T. Al-Khateeb, and Christos Aloupis

Publication:

Symposium Papers

Volume:

340

Abstract:

The maintenance and management of segmental-concrete cable-stayed bridges represents a major investment of human and financial capital. One possible approach to reducing this cost while simultaneously improving the process, is by using structural health monitoring (SHM) systems. The Delaware Department of Transportation (DelDOT), working collaboratively with the University of Delaware (UD) Center for Innovative Bridge Engineering, installed a comprehensive SHM system on the 1,749 ft (533 m) long Indian River Inlet Bridge (IRIB) during construction. The SHM system is fiber-optic based with more than 120 sensors of varying type distributed throughout the bridge. Within the first year of service, a series of three controlled diagnostic load tests were conducted utilizing the installed SHM system. The test results have been used to establish a standard set of truck passes for future tests, and the recorded response has been used to establish a baseline against which future test results can be compared. These comparisons will yield a quantitative measure of how the bridge is performing, and in combination with the more qualitative biennial inspections, will enable DelDOT to better manage this critical infrastructure asset.

DOI:

10.14359/51725806


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