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From page 15... ... As described in Chapter 2, each connection type is evaluated on the basis of the following: • Performance potential, which is a composite of construction risk, seismic performance, durability, and post-earthquake inspectability • Time savings potential • Technology readiness The reader is referred to Appendix H for detailed information about each connection type. Additionally, the appendix provides information on material requirements, construction techniques, and detailed evaluation of laboratory testing of representative specimens of the connection type. Read the entire page →
From page 16... ... Performance potential of bar coupler connections. Threaded sleeve Headed bars with mating sleeves External clamping screws Grouted splice sleeve Performance Potential Definition Relative to CIP Construction Risk Value Seismic Performance Value Durability Value Inspectability Value +2 Much better +1 Slightly better 0 Equal 6 6 7 1 2 3 4 5 6 1 2 3 4 6 7 –1 Slightly worse 1 2 3 4 5 1 2 3 4 5 7 5 –2 Much worse 7 Read the entire page →
From page 17... ... Time Savings Potential Definition Relative to CIP Value +2 Much better 1 2 4 5 +1 Slightly better 3 6 0 lauqE –1 Slightly worse 7 –2 Much worse Grouted Ducts Description In grouted duct connections, reinforcing bars extending from one precast member are inserted into ducts cast into the second, and the ducts are then grouted. The hardened grout anchors the bar in the duct. Read the entire page →
From page 18... ... Performance potential evaluation for grouted duct connections. Performance Potential Definition Relative to CIP Construction Risk Value Seismic Performance Value Durability Value Inspectability Value +2 Much better +1 Slightly better 0 Equal 2 3 1 2 3 4 5 6 1 2 3 4 5 6 7 2 3 5 6 –1 Slightly worse 1 4 5 6 7 7 1 4 7 –2 Much worse Read the entire page →
From page 19... ... . This connection type can be used in the following locations: • Column to cap beam • Footing to column • Pile to pile cap Performance and Time Savings Evaluation Performance grades were assigned based on the comments outlined in Appendix C regarding construction risk, seismic performance, inspectability, and durability (see Table 17) Read the entire page →
From page 20... ... By contrast, in a cap beam equipped with grouted ducts or sleeves, no column jacks are needed and the grout in the bed needs to gain only enough strength to carry the beam's weight through compression. Technology Readiness Based on the level of seismic research, available design guidance, and use in practice, the evaluated pocket connections achieved TRL scores as shown in Table 19. Read the entire page →
From page 21... ... Connection examples are provided in Appendix D This connection type can be used in the following locations: • Footing to column • Column to cap beam • Pile to pile cap Performance and Time Savings Evaluation Performance scores were assigned based on the comments listed in Appendix D regarding construction risk, seismic performance, inspectability, and durability and are given in Table 20. Read the entire page →
From page 22... ... Performance and Time Savings Evaluation Performance scores were assigned based on the foregoing discussion regarding construction risk, seismic performance, inspectability, and durability (see Table 23) Read the entire page →
From page 23... ... Performance potential of hybrid connections. Performance Potential Definition Relative to CIP Construction Risk Value Seismic Performance Value Durability Value Inspectability Value +2 Much better 5 +1 Slightly better 4 1 2 3 6 7 8 8 0 Equal 8 4 4 8 –1 Slightly worse 1 3 5 6 7 4 1 2 3 5 6 7 1 2 3 5 6 7 –2 Much worse 2 Table 24. Read the entire page →
From page 24... ... The most typical application of integral connections is the integral cap beam/diaphragm to girder connection for a steel/concrete composite bridge. Such connections have historically been constructed with CIP methods, but with ABC, these may use a steel or precast concrete stayin-place formwork that is filled with reinforced concrete to integrate the bridge components in the joint area. Read the entire page →
From page 25... ... Examples of integral connections can be found in Appendix F This connection type can also be used in the following locations: • Pile to pile cap • Spread footing or pile cap to column Performance and Time Savings Evaluation The performance ratings of integral connections are provided in Table 26. Read the entire page →
From page 26... ... Performance potential evaluation for integral connections. Performance Potential Definition Relative to CIP Construction Risk Value Seismic Performance Value Durability Value Inspectability Value +2 Much better 5 +1 Slightly better 3 3 0 Equal 3 4 6 8 9 1 2 4 5 6 8 9 11 1 2 4 5 6 7 8 9 11 3 5 6 7 8 9 10 11 –1 Slightly worse 1 2 7 10 11 7 10 1 2 4 –2 Much worse 10 Read the entire page →
From page 27... ... Time Savings Potential Definition Relative to CIP Value +2 Much better 1 2 4 10 +1 Slightly better 7 8 9 0 11653lauqE –1 Slightly worse –2 Much worse Technology Readiness Level (TRL) % of Development Complete 001-5757-0505-5252-0noitpircseDLRT 1 Concept exists 2 Static strength predictable 3 Non-seismic deployment 4 Analyzed for seismic loading 5 Seismic testing of components 6 Seismic testing of subassemblies 7 Design and construction guidelines 8 Deployment in seismic area 9 Adequate performance in earthquake Read the entire page →
From page 28... ... Technology readiness. The TRL and the completeness of development for the elastomeric bearing connection is shown 28 Figure 18. Read the entire page →
From page 29... ... Performance Potential Definition Relative to CIP Construction Risk Value Seismic Performance Value Durability Value Inspectability Value +2 Much better 1 +1 Slightly better 2 0 Equal –1 Slightly worse 1 2 1 2 –2 Much worse 1 2 Time Savings Potential Definition Relative to CIP Value +2 Much better +1 Slightly better 0 lauqE –1 Slightly worse –2 Much worse 1 2 Technology Readiness Level (TRL) % of Development Complete 001-5757-0505-5252-0noitpircseDLRT 1 Concept exists 2 Static strength predictable 3 Non-seismic deployment 4 Analyzed for seismic loading 5 Seismic testing of components 6 Seismic testing of subassemblies 7 Design and construction guidelines 8 Deployment in seismic area 9 Adequate performance in earthquake Read the entire page →
From page 30... ... Technology readiness level evaluation for emerging technologies. Technology Readiness Level (TRL) Read the entire page →
From page 31... ... • In the precast systems, the majority of the time savings arises from precasting the cap beam, leading to 9 to 10 days savings for bar coupler, grouted duct, and socket-type connections used to facilitate the placement of a cap beam. Pocket-type connections saved about half that time due to the curing time of concrete in the pocket. Read the entire page →
From page 32... ... This classification tool then is useful for focusing the designer's attention on the elements and connections that require the most attention in seismic design. Bent Systems The approach for considering ABC in seismic regions has been one using "building blocks" of connection types. Read the entire page →
From page 33... ... An example of one of the bents used along the Interstate-15 corridor near Salt Lake City is shown in Figure 24, where precast columns are connected to foundations and cap beams using grout-filled bar couplers (splice sleeves) Read the entire page →
From page 34... ... Precast columns along with precast lower-stage cap beams are used in this project, thus, making use of grouted duct, member socket, and integral connection types. The demonstration project also uses precast, prestressed decked-bulb tees as superstructure. Read the entire page →
From page 35... ... To some extent, the work underway on integral connections seeks to fill in gaps in knowledge that may exist for non-ABC or partial-ABC applications, for example, precast girder superstructures with CIP substructure. Nonetheless, quantification of performance levels for integral connections is, and will continue to be, an important area of research for ABC in seismic regions. Read the entire page →
From page 36... ... Bar couplers are quite widely used already, largely because of their convenience and the fact that they open the door to precasting. The major finding with respect to bar couplers is the paucity of comprehensive test data available to support their use in high seismic zones. Read the entire page →
From page 37... ... In addition to physical testing, work also needs to be done to develop formal guidelines for use of bar couplers and suitable specification language to regulate design of not only the coupler itself but also the connection region immediately surrounding it. Examples are included in the Required Design Specifications section that follows the individual connection knowledge gap summaries. Read the entire page →
From page 38... ... Design guidance and specification requirements are included in the Required Design Specifications section. Pocket Connection Systems Pocket details are likely to be restricted to connections between a column and precast cap beam because the geometry of the connection at a footing makes casting the pocket concrete difficult. Read the entire page →
From page 39... ... Design guidance and specification requirements are included in the Required Design Specifications section. Hybrid Connection Systems Hybrid connections hold the promise of superior seismic performance, but are not inherently rapid to construct. Read the entire page →
From page 40... ... Where interruptions in stirrups occur to permit girders to be placed, what details will provide adequate performance? For the commonly used drop cap bents, the primary outstanding design guidance and specification requirements are included in the Required Design Specifications section. Read the entire page →
From page 41... ... Design guidance required. Read the entire page →
From page 42... ... Suggested testing includes the following: • Subassemblage test for flush-soffit integral connections with precast cap beams • Subassemblage testing of commonly used integral connections with two-stage cap beams (dropped cap beams) • Shake table concept validation testing of large-scale bent systems Much experience remains to be gained before owners and engineers will be satisfied with the actual field performance of ABC bridge systems. Read the entire page →

From page 15...

... As described in Chapter 2, each connection type is evaluated on the basis of the following: • Performance potential, which is a composite of construction risk, seismic performance, durability, and post-earthquake inspectability • Time savings potential • Technology readiness The reader is referred to Appendix H for detailed information about each connection type. Additionally, the appendix provides information on material requirements, construction techniques, and detailed evaluation of laboratory testing of representative specimens of the connection type.