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Reinforced concrete sections have typically been the most used material for hardened protective construction due to their mass and the ductility provided by the reinforcement. The additional mass of these sections reduces deflections and increases dampening, which reduces vibrations. Even for the occasional occurrence of hardened steel structures, the foundation is comprised of reinforced concrete. Reinforced concrete structures are hardened for a multitude of reasons. The most common include antiterrorism, force protection, equivalent protection for quantity distance arc violations, personnel protection, prevention of prompt propagation, asset protection, and elastic response during repeated intentional detonations. Many of the structures in the United States (US) used by the Department of Defense (DoD), to accommodate a rapid increase in production and storage of explosives were built during World War II (1941-1945). Facilities used for explosives production, maintenance, research and development (R&D), demolition, testing, and training are commonly referred to as Explosives Operating Locations (EOLs). This puts the average age of many of these facilities close to 80 years-old, which is past their originally intended service life. This paper presents a structural health and visual inspection (SHVI) technique developed by the U.S. Army Corps of Engineers (USACE) Facilities Explosives Safety Mandatory Center of Expertise (FES MCX), the University of Oklahoma, and the Engineering Research and Development Center (ERDC) Geotechnical and Structures Laboratory (GSL) for the inspection of reinforced concrete Explosives Operations Location (EOL) facilities and live-fire training facilities [9]. This inspection process has been utilized to inspect over 1500 structures across multiple countries over the last decade and aid DoD installations in planning and budgeting for necessary repairs and future recapitalization priorities. This work does not include application to anti-terrorism or force protection in hardened structures for conventional weapon effects. This process has also been modified for use in live-fire training operations in concrete facilities and coupled with analyses to determine facility adequacy for explosives operations with desired charge weights, based on the given facility’s current structural health rating and its analyzed ability to remain elastic during repeated intentional detonations. The FES MCX partners with ERDC for concrete coring, materials analysis, and testing of samples to determine the estimated remaining service life of concrete structures based on the carbonation front of cored samples determined by the carbonation tests in relationship to the steel reinforcement. Examples of historical application will be given, and details provided on how these methods can lead to improved life-cycle cost for concrete structures and paired with design development criteria for optimal results.

Reinforced concrete sections have typically been the most used material for hardened protective construction due to their mass and the ductility provided by the reinforcement. The additional mass of these sections reduces deflections and increases dampening, which reduces vibrations. Even for the occasional occurrence of hardened steel structures, the foundation is comprised of reinforced concrete. Reinforced concrete structures are hardened for a multitude of reasons. Some of the most common include antiterrorism, force protection, equivalent protection for quantity distance arc violations, personnel protection, prevention of prompt propagation, asset protection, and elastic response during repeated detonations. Many of the structures used in the Department of Defense (DoD), for these purposes, were built in the United States (US) during the World War II era (1941-1945) for a rapid increase in production and storage of explosives. This puts the average age of many of these facilities at close to 80 years-old, which is past their originally intended service life. This paper presents a structural health and visual inspection technique developed by the U.S. Army Corps of Engineers (USACE) Engineering and Support Center Huntsville (CEHNC) Facilities Explosives Safety Mandatory Center of Expertise (FES MCX) and the Engineering Research and Development Center (ERDC) Geotechnical and Structures Laboratory (GSL) for the inspection of reinforced concrete earth covered magazines (ECMs) [9]. This inspection process has been utilized to inspect over 1500 earth covered magazines across multiple countries over the last decade and aid DoD installations in planning and budgeting for concrete repairs and ECM replacements. The CEHNC FES MCX partners with ERDC for concrete coring and testing of samples to determine the estimated remaining service life of concrete structures based on the carbonation front of cored samples determined by the carbonation tests in relationship to the steel reinforcement. Examples of historical application will be given, and details provided on how these methods can lead to improved life-cycle cost and decision making.

Through a Change Proposal by Facca Incorporated, the Ontario Ministry of Transportation (MTO) approved the replacement of the as-tendered steel H-piles by newly designed prestressed/precast Ultra-High-Performance Concrete (UHPC) piles for supporting the west abutment of the Lily River Detour Bridge. The 300 mm (~12”) deep UHPC piles were designed and installed at the west abutment based on the previous successful development and testing of a tapered H-shaped pile at Iowa State University. The east abutment, as tendered, was designed to be supported by six steel H-shaped battered piles driven to bedrock. For the west abutment, six UHPC piles were produced and installed using the same batter. Since the site contained occasional boulders and the design intent to drive the piles to bedrock, the UHPC piles were fitted with steel shoes for the first time. All piles were successfully installed to reach the targeted load bearing capacities. After the replacement bridge was constructed, the detour bridge was removed and the UHPC piles were extracted to examine the conditions of the piles. This presentation will provide details of the innovative design of the piles, fabrication and driving of the piles, and lessons learned from analyzing the driving data and removal of the piles. Fellowship and Scholarship recipients. With the help of generous donors from the concrete community, the ACI Foundation awards high-potential undergraduate and graduate students in engineering, construction management, and other appropriate curricula.

Due to an industry wide effort, high-strength reinforcement (HSR) up to Grade 100 is now allowed by ACI 318-19. To date, the ACI Foundation, Charles Pankow Foundation, Concrete Reinforcing Steel Institute, and others have provided more than $3 million in combined funding for HSR research projects.

The present paper shows the study of a mixture design of the concrete used in the reinforced foundations of the bridge on the Straits of Messina in Italy. A cube compressive characteristic strength of 35 MPa (5,075 psi) is required for the foundation concrete. Due to the peculiar shape of the concrete foundations (completely embedded in the excavated ground), the damages caused by the thermal stress, the steel corrosion, and the alkali-silica reaction cannot be monitored and repaired. Therefore, a concrete structure must be designed without any damage for at least 200 years due to the very important role of this structure from a social point of view. In order to guarantee this long-term durability, there are two problems to be faced and solved: 1) the heat of cement hydration could cause cracks inside the foundation due to thermal gradients between the hotter nucleus of the massive structure and the colder peripheral areas; 2) the corrosion of the metallic reinforcements caused by the reaction between the metallic iron and the oxygen (O₂) present in the air to an extent of about 20%; 3) the alkali-silica reaction causing a local disruption in the concrete. All these problems can be solved using a blast-furnace slag cement such as CEM III B 32.5 R characterized by a very small heat of hydration and adopting a ground coarse aggregate with a maximum size as large as 32 mm (1.28 in): the choice of this aggregate produces a reduction in the amount of mixing water and then of the cement content and reduces the volume of the entrapped air at about 1.3% by concrete volume. This amount of O₂ would cause the corrosion of a negligible amount of iron corresponding to only 10 to 13 g (0.4 to 0.5 oz) of steel in 1 m³ (1.31 yd³) of concrete of each foundation. In order to prevent any ingress of air from the environment, the top of the foundation should be protected by self-compacting, self-compressing, and self-curing concrete.