Structural integrity of precast concrete modular construction

PCI Journal ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 58-70
Author(s):  
Jeff M. Wenke ◽  
Charles W. Dolan
Keyword(s):  
Prestressed Concrete ◽  
Structural Integrity ◽  
Precast Concrete ◽  
Building Code ◽  
Modular Construction ◽  
Structural Concrete ◽  
Partial Removal ◽  
Structural Walls ◽  
Construction Methods ◽  
General Services Administration

The American Concrete Institute’s (ACI’s) Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19) contains structural integrity provisions for precast concrete panel buildings but does not address the structural integrity of precast concrete modules. ACI 318 requires spaced steel ties in all directions to tie the precast concrete panel elements together. These criteria are impractical for precast concrete modules due to the construction methods and the overall rigidity of each module. Precast concrete modules are inherently stable, even when subjected to General Services Administration criteria for partial removal of structural walls or corners, which require that if a portion of a wall or an entire module is removed, the remaining portions must have sufficient capacity to carry the resulting gravity loads. This paper examines the stress increases due to partial wall removal and the possibility of total module removal. It discusses strength reserves, provides recommendations for future editions of ACI 318 and the PCI Design Handbook: Precast and Prestressed Concrete, and presents conceptual connections that provide the continuity and ductility needed to maintain structural integrity following total module removal.

PCI Standard Design Practice Ref ACI 318-14

2021 ◽  
Author(s):  
Keyword(s):  
Prestressed Concrete ◽  
Precast Concrete ◽  
Building Code ◽  
Design Practice ◽  
Structural Concrete ◽  
Design Engineers ◽  
Standard Design ◽  
Precast Prestressed Concrete ◽  
Consistent Approach ◽  
Code Provisions

Precast, prestressed concrete design is based on conformance with the provisions of the American Concrete Institute’s (ACI’s) Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14). In most cases, these provisions are followed explicitly. Occasionally, interpretation of some sections of ACI 318 is required to ensure quality is maintained in conjunction with the unique characteristics of precast and prestressed concrete fabrication, shipping, and erection. Members of the PCI Building Code Committee, along with other experienced precast concrete design engineers, have identified code provisions, detailed in this publication, that require clarification or interpretation. These design practices are followed by most precast concrete design engineers to produce safe, economical precast concrete structures and they provide a consistent approach for the designers and contractors.

scholarly journals Hysteretic Response of Tilt-Up Concrete Precast Walls with Embedded Steel Plate Connections

2020 ◽  
Vol 12 (19) ◽  
pp. 7907
Author(s):  
Hyun-Do Yun ◽  
Hye-Ran Kim ◽  
Won-Chang Choi
Keyword(s):  
Prestressed Concrete ◽  
Structural Integrity ◽  
Precast Concrete ◽  
American Concrete Institute ◽  
Steel Plates ◽  
Test Results ◽  
Wall Panel ◽  
Concrete Wall ◽  
Concrete Panels ◽  
Wall Panels

Many connection systems are available that can transfer tension and shear loads from a precast concrete wall panel to a floor slab. However, due to the insufficient anchor depth in relatively thin precast concrete panels, it is difficult to attain adequate ductility and stiffness to ensure structural integrity. Based on the authors’ previous research results, the supplementary reinforcement of embedded steel plates in precast concrete wall panels can enhance stiffness while maintaining allowable displacement and ductility. In this study, three full-size tilt-up precast concrete panels with embedded steel plates were fabricated. Lateral cyclic loads were applied to full support structures consisting of a precast concrete wall panel and a foundation. The test results were compared with the results predicted using existing code equations found in the American Concrete Institute 318-14 and the Prestressed Concrete Institute Handbooks. The test results confirm that the supplementary reinforcement of thin precast concrete wall panels can provide (i) the required strength based on current code equations, (ii) sufficient ductility, and (iii) the energy dissipation capacity to resist cyclic loading.

Performance of Precast Concrete Building Structures

2012 ◽  
Vol 28 (1_suppl1) ◽  
pp. 349-384 ◽  
Author(s):  
S. K. Ghosh ◽  
Ned M. Cleland
Keyword(s):  
Prestressed Concrete ◽  
Precast Concrete ◽  
Lateral Force ◽  
Building Code ◽  
Earthquake Resistance ◽  
Building Structures ◽  
Building Systems ◽  
Concrete Building ◽  
Precast Prestressed Concrete ◽  
Code Provisions

The Precast/Prestressed Concrete Institute (PCI) sent an assessment team to Chile, which visited the areas affected by the 27 February 2010 earthquake between 26 and 30 April 2010. This paper reports on the team's observations on the performance of precast/prestressed concrete structures. The precast concrete building systems observed by the PCI team generally performed well. In some cases, the lateral force-resisting system performed satisfactorily, but the absence or weakness of diaphragm framing resulted in local failures. Overall, the PCI team found a mature and sophisticated precast concrete industry that has successfully considered and solved issues of earthquake resistance without some of the constraints imposed on U.S. practice by restrictive building code provisions.

scholarly journals Experimental Study of a New Precast Prestressed Concrete Joint

2018 ◽  
Vol 8 (10) ◽  
pp. 1871 ◽  
Author(s):  
Xueyuan Yan ◽  
Suguo Wang ◽  
Canling Huang ◽  
Ai Qi ◽  
Chao Hong
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Prestressed Concrete ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Frame Structure ◽  
Loading Test ◽  
Concrete Frame ◽  
Concrete Joints ◽  
Precast Prestressed Concrete

Precast monolithic structures are increasingly applied in construction. Such a structure has a performance somewhere between that of a pure precast structure and that of a cast-in-place structure. A precast concrete frame structure is one of the most common prefabricated structural systems. The post-pouring joint is important for controlling the seismic performance of the entire precast monolithic frame structure. This paper investigated the joints of a precast prestressed concrete frame structure. A reversed cyclic loading test was carried out on two precast prestressed concrete beam–column joints that were fabricated with two different concrete strengths in the keyway area. This testing was also performed on a cast-in-place reinforced concrete joint for comparison. The phenomena such as joint crack development, yielding, and ultimate damage were observed, and the seismic performance of the proposed precast prestressed concrete joint was determined. The results showed that the precast prestressed concrete joint and the cast-in-place joint had a similar failure mode. The stiffness, bearing capacity, ductility, and energy dissipation were comparable. The hysteresis curves were full and showed that the joints had good energy dissipation. The presence of prestressing tendons limited the development of cracks in the precast beams. The concrete strength of the keyway area had little effect on the seismic performance of the precast prestressed concrete joints. The precast prestressed concrete joints had a seismic performance that was comparable to the equivalent monolithic system.

scholarly journals SHEAR PERFORMANCE OF SPECIAL DRY JOINTS FOR PRECAST CONCRETE SEGMENTS

2021 ◽  
Vol 11 (1) ◽  
pp. 60-72
Author(s):  
Watanachai Smittakorn ◽  
Tosporn Prasertsri ◽  
Worapon Pattharakorn ◽  
Pitcha Jongvivatsakul
Keyword(s):  
Prestressed Concrete ◽  
Precast Concrete ◽  
High Strength ◽  
Shear Capacity ◽  
Fiber Volume ◽  
Strength Concrete ◽  
Test Parameters ◽  
Ductile Shearing ◽  
Shear Performance ◽  
Normal Strength

The special dry joints for precast prestressed concrete segments are invented in this study toovercome the limitation of conventional dry joints. Eight specimens of special dry joints were madeand subjected to direct shear test. Test parameters comprise concrete compressive strength (normaland high strength concrete) and steel fiber volume added in the special dry joint (0%, 0.5%, and1.0%). Test results revealed that the inclusion of steel fibers remarkably enhanced the shear capacityand ductility index. Failure mode of specimens was changed from shearing off to concrete crackingaround shear key corners, defined as ductile shearing-off failure. Furthermore, the existing equationsfor predicting shear capacity of keyed joints were validated by the experimental results. Amongavailable equations from literatures, the Turmo’s equation yields better prediction of the shearcapacity for the special dry joint made with normal strength concrete.

scholarly journals Development of an Innovative Modular Foam-Filled Panelized System for Rapidly Assembled Postdisaster Housing

Buildings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 97 ◽  
Author(s):  
P. Sharafi ◽  
S. Nemati ◽  
B. Samali ◽  
M. Ghodrat
Keyword(s):  
Sandwich Panel ◽  
High Density ◽  
Building Construction ◽  
Structural Performance ◽  
Modular Construction ◽  
Structural Walls ◽  
Pu Foam ◽  
Load Carrying ◽  
Foam Filled ◽  
American Society

In this paper, the development process of a deployable modular sandwich panelized system for rapid-assembly building construction is presented, and its structural performance under some different action effects is investigated. This system, which includes an innovative sandwich panel and its integrated connections, can be used as structural walls and floors in quickly-assembled postdisaster housing, as well as load-bearing panels for prefabricated modular construction and semipermanent buildings. Panels and connections are composed of a pneumatic fabric formwork, and two 3D high-density polyethylene (HDPE) sheets as the skins, filled with high-density rigid polyurethane (PU) foam as the core. HDPE sheets manufactured with a studded surface considerably enhance stress distribution, buckling performance, and delamination strength of the sandwich panel under various loading conditions. The load-carrying behavior of the system in accordance with some American Society for Testing and Materials (ASTM) standards is presented here. The results show the system satisfies the codes’ criteria regarding semipermanent housing.

Saint-Venant torsion constant of modern precast concrete bridge girders

PCI Journal ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 23-31
Author(s):  
Richard Brice ◽  
Richard Pickings
Keyword(s):  
Prestressed Concrete ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
The United States ◽  
Bridge Girders ◽  
Concrete Bridge ◽  
Approximate Methods ◽  
Standard Design ◽  
Prestressed Concrete Bridge ◽  
Precast Prestressed Concrete

Many bridge owners have developed new precast, prestressed concrete bridge girder sections that are optimized for high-performance concrete and pretensioning strands with diameters greater than 0.5 in. (12.7 mm). Girder sections have been developed for increased span capacities, while others fill a need in shorter span ranges. Accurate geometric properties are essential for design. Common properties, including cross-sectional area, location of centroid, and major axis moment of inertia, are generally easy to compute and are readily available in standard design references. Computation of the torsion constant is a different matter. This paper presents the methods and results of a study to determine the torsion constant for many of the modern precast, prestressed concrete bridge girders used in the United States and compares the results with values from the approximate methods of the AASHTO LRFD specifications.

scholarly journals A Review of Precast Concrete Beam-to-Column Connections Subjected to Severe Fire Conditions

2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Noor Azim Mohd Radzi ◽  
Roszilah Hamid ◽  
Azrul A. Mutalib ◽  
A. B. M. Amrul Kaish
Keyword(s):  
Large Scale ◽  
Concrete Beam ◽  
Structural Integrity ◽  
Precast Concrete ◽  
Analytical Models ◽  
Fire Effect ◽  
The Moment ◽  
The Impact ◽  
Comprehensive Study ◽  
Fire Conditions

Fire exposure can have a significant impact on the structural integrity and robustness of precast concrete beam-to-column connections. Given the importance of fire safety in the design of a structure, it is critical to understand the damage that may occur in the event of a fire to be able to prevent the building from collapsing. No comprehensive study has been carried out to determine the effects of fire on semirigid and pinned concrete beam-to-column connections. Most studies focused on the impact of exposure of rigid concrete beam-to-column connections to high temperatures. This paper is a comprehensive review of the literature on the performance of precast concrete beam-to-column connections under fire conditions. The key areas in this review are the moment-rotation-temperature characteristics and fire effect on precast concrete beam-to-column connections. This paper focuses primarily on the case studies of real fires, large-scale fire tests, computer simulations and analytical models, fire resistance tests on the connection elements, and assessment and rehabilitation of fire-damaged precast concrete. The paper also discusses the current issues and possible challenges.

INFLUENCE OF RECTANGULAR STEEL SPLICE-SLEEVE FOR PRECAST CONCRETE CONNECTION

2015 ◽  
Vol 77 (12) ◽  
Author(s):  
Ahmad Baharuddin Abd Rahman ◽  
Tan Kee Hong ◽  
Izni Syahrizal Ibrahim ◽  
Roslli Noor Mohamed
Keyword(s):  
Structural Integrity ◽  
Precast Concrete ◽  
Tensile Load ◽  
Steel Plates ◽  
Steel Bar ◽  
Tensile Performance ◽  
Bond Property ◽  
The Many ◽  
Steel Sleeve

Precast concrete building system has gained its popularity in Malaysia because of the many advantages such as high quality of structural components, less labour intensive at the construction site, and shorter completion time of a project. One of the constraints in precast concrete structures is to ensure that the connections are strong enough to ensure the structural integrity and robustness of the overall frames. In this study, a total of nine rectangular steel splice-sleeve connections were tested experimentally under incremental tensile loads. Two steel plates were inserted and welded to each end of the steel splice-sleeve. The steel plates act as shear key to provide the interlocking mechanism to the grout and to enhance the bond property between the grout and the splice. These plates were adopted to prevent the grout slippage from the sleeve. The grout strength, embedded steel bar lengths and the size of the steel sleeve splice were varied among the specimens to study their effect on the tensile performance of the connection. The results showed that the higher strength of grout, longer embedded length of steel bar and smaller size of the sleeve contributes to a higher ultimate tensile load.

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