
The substructure and superstructure of the Bayonne Bridge are both precast, post-tensioned concrete, making it a one-of-a-kind structure.
Oscar R. Antommattei, MS, PE, FACI
Kiewit Engineering Group Inc.
What is your background and area of expertise?
My background is mainly concrete materials with experience in inspection, design, production and construction of concrete structures. My main areas of concrete expertise are mixture proportioning, thermal control planning, service life and durability, constructability, troubleshooting and forensic investigations.
How did you become interested in doing what you do?
My interest for concrete started during my undergraduate years while studying at the University of Puerto Rico-Mayaguez, where I had the opportunity to join the ASCE student competitions and participate in the Concrete Canoe competitions. At that time, I had a lot of interest in the structural design and construction aspects of civil engineering, but I found concrete materials to be a combination of both technical areas. Concrete as a structural material with very technical properties used for design and concrete as a construction material for different construction applications and field operations became my main focus of interest. Concrete also was present in my initial professional opportunities within the industry. I started my career in concrete production then worked on concrete structural inspection and construction, so I pursued graduate studies at Clemson University to further enhance my knowledge and opportunities in the concrete industry. Once I completed my master’s degree at Clemson, I worked for an engineering consulting firm with an emphasis on forensics of concrete materials, design and construction projects, where I was able to gain expertise in numerous technical aspects of concrete. In 2012, Kiewit was looking to develop a concrete engineering department, so I joined Kiewit in the role as the in-house concrete expert. After 10 years at Kiewit, I lead a group of concrete engineers supporting Kiewit projects.
What types of projects do you typically oversee?
At Kiewit, we get to see a wide variety of projects, such as buildings, bridges, highways, ports, dams, power plants and tunnels, among others, but most typically it is large, heavy civil type infrastructure projects. We provide concrete technical services to support the design and construction teams for numerous projects as well as facilitating training on concrete quality and best practices within Kiewit and the industry. In our role as concrete engineering professionals, we get involved from the early stages of estimating and prebid design to the preconstruction, design, construction and postconstruction stages, depending on project needs. Every week, we typically get involved with five to 10 different projects, so that keeps the work interesting with sufficient level of difficulty and variety, so it is never boring.

Concrete structures used in SoFi Stadium in Inglewood, Calif., had to meet stringent performance requirements for seismic conditions.
What are some unique or noteworthy projects on which you specified precast concrete?
I believe some of the most noteworthy projects where we have used precast concrete are the State Road 520 Floating Bridge, the Bayonne Bridge and, most recently, Sofi Stadium. These three projects certainly are on the top of my most favorite projects in Kiewit. The SR520 Floating Bridge was fascinating given all the complexities and unique features in the design of a floating bridge. The Bayonne Bridge was very interesting since both the substructure and superstructure are precast, post-tensioned concrete, which makes it one of a kind. SoFi Stadium was fascinating given it had massive concrete structures that needed to be constructed with stringent performance requirements for seismic conditions and included very large posttensioned precast segmental architectural columns that require use of self-consolidated concrete. In all these projects, our technical focus was supporting the design and construction operations with the concrete materials and thermal controls expertise to ensure the performance goals met the required quality expectations.

The SR520 Floating Bridge between Seattle and other communities on Lake Washington was the world’s longest floating bridge when it opened in 2016, replacing a 1963 structure, and was built to withstand a 100-year storm.
What benefits does precast concrete offer your projects?
The most important benefits of precast concrete are the versatility of design, better control of quality in construction and improved schedule while maintaining the design performance in service. In essence, precast concrete allows many projects to become feasible alternatives that can be made a reality when cast-in-place is not possible or not justified given the local project conditions or access limitations.
How do you see the role of precast concrete as a building material changing in the future?
The future of concrete and precast concrete should be expected to be mainly affected by new code standards, development of new materials technologies, the need for improved service life and durability, use of alternative cementitious materials, implementation of performance requirements and use of sustainable strategies in design and construction to improve resiliency of structures and reduce carbon footprint of concrete. Precast concrete will have a major role in the industry’s future given its ability to be versatile and efficient with improved control in design, production and construction in a manufacturing facility. I believe that we will continue to see more use of precast concrete structures in future projects.
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