Revision of the AIJ Recommendations for Construction Practice of Reinforced Concrete with Half Precast Concrete Members

2020 ◽  
Vol 58 (11) ◽  
pp. 865-870
Author(s):  
H. Sugiyama ◽  
S. Watanabe
2011 ◽  
Vol 243-249 ◽  
pp. 5427-5434
Author(s):  
Hui Qian ◽  
Hong Nan Li ◽  
Di Cui ◽  
Huai Chen

Shape memory alloys (SMAs) are unique class materials that have the ability to undergo large deformations, while returning to their undeformed shape through either the applications of heat (SME) or removal of stress (SE). The unique properties lead to their wide applications in the biomedical, mechanical, aerospace, commercial industries, and recently in civil engineering. The paper presents two case studies of structural seismic vibration control using SMAs. The first one is a study of the SMA reinforced RC members. Two innovative applications in RC members, such as SMA-based Precast Concrete Frame Connection (SMA-PCFC), and SMA reinforced RC short column, were proposed. Moreover, the self-rehabilitation properties of SMAs-based Intelligent Reinforced Concrete Beams (SMA-IRCBs) were further experimentally investigated. The results show that SMAs can improve the mechanical properties of concrete members. SMA reinforced RC members have unique seismic performance compared to ordinarily steel reinforced concrete members. The second one is a study of the structural energy dissipation system using SMAs damping device. An innovative hybrid SMAs friction device (HSMAFD) which consists of pre-tensioned superelastic SMA wires and friction devices (FD) was presented. The results of cyclic tensile tests show that the HSMAFD exhibits stable large energy dissipation capacity and re-centering feature. The effectiveness of the HSMAFD in reducing horizontal response of structures subjected to strong seismic excitations was verified through shaking table tests carried out on a reduced-scale symmetric steel frame model with and without the HSMAFD.


2001 ◽  
Vol 28 (4) ◽  
pp. 715-737
Author(s):  
Murat Saatcioglu ◽  
Denis Mitchell ◽  
René Tinawi ◽  
N John Gardner ◽  
Anthony G Gillies ◽  
...  

The 1975 Turkish code provisions are first reviewed to provide the background for design and detailing of structures prior to the earthquake. The performance of reinforced concrete and masonry structures is described indicating many of the deficiencies in design, detailing, and construction execution. The behaviour of precast concrete structures, steel structures, and industrial facilities is also presented. The provisions of the 1997 Turkish building code are summarized and a description of new construction provides evidence of both excellent and poor construction practice. Some examples of retrofitting of damaged structures soon after the earthquake are also presented.Key words: seismic design, earthquake, Kocaeli, structures, codes, concrete, precast concrete.


2021 ◽  
Author(s):  
Norinobu Katayama ◽  
Kazuhiko Fujisaki ◽  
Takehisa Ueno ◽  
Ryutaro Onishi ◽  
Isamu Yoshitake

The decline in the number of persons of working age is a social problem in Japan. This is a particularly serious concern for workers in the construction field; construction systems should be considered for productivity improvements. Prefabrication systems are an effective method for shortening construction cycles and times. In fact, various precast concrete members have been employed to realize more rapid construction and improvements in quality. Using precast concrete members is difficult because jointless roads are preferable for highway pavement. Continuously reinforced concrete pavement (CRCP), which has the advantages of concrete jointless construction and high ductility, is a suitable method for highway road construction. Typical Japanese highways built with CRCP reduce the amount of horizontal cracking by arranging transverse rebars at an angle of 60° to the main rebars. Note that rebar placement and bonding in conventional CRCP are troublesome and labor intensive owing to the long construction time required. We have developed prefabricated steel bar meshes for CRCP and can report some benefits relating to their practical application. To examine the fundamental properties of mesh panels, we conducted a laboratory experiment and a simulated field test. The primary concern of welded rebars are failures induced by cyclic loading. A flexural fatigue loading test using CRCP models was conducted. In addition, a comparative survey on conventional and prefabrication systems was performed in the simulated field test to quantify the constructability of CRCP and to observe the extent of cracking in concrete. This paper reports on our experimental investigation.


2021 ◽  
Author(s):  
Sven Bosbach ◽  
Christian Knorrek ◽  
Josef Hegger ◽  
Alexander Stark

<p>The requirements for existing bridge structures increased significantly in the last years because of increasing traffic volume and higher total vehicle weights. Strengthening of existing bridges as well as necessary reconstructions are expensive, often complex and strongly influence traffic. Hence, the development of new methods for sustainable bridge constructions with short erection periods becomes a macroeconomic issue. Modular bridge constructions made of precast concrete elements with reinforcement systems made of corrosion-resistant carbon fibre reinforced polymer (CFRP) represent a particularly suitable solution for these demands. Modular systems are reasonable to realise short construction times and the application of durable CFRP reinforcement ensures a longer lifetime of the bridge. This paper reports on a developed concept for a modular system made of prefabricated concrete elements with CFRP reinforcement and on tests investigating the structural behaviour of prestressed CFRP reinforced concrete members.</p>


PCI Journal ◽  
2012 ◽  
Vol 57 (3) ◽  
pp. 33-46 ◽  
Author(s):  
Nemkumar Banthia ◽  
Vivek Bindiganavile ◽  
John Jones ◽  
Jeff Novak

2020 ◽  
pp. 49-52
Author(s):  
S.E. YANUTINA ◽  

The relevance of research in the factory laboratory of JSC «198 KZHI», which is part of the HC GVSU «Center», is dictated by the need to dispose of foam polystyrene waste that occurs in large quantities when producing the precast concrete. In the production of three-layer external wall panels, polystyrene heatinsulating plates of the PPS 17-R-A brand are used as an effective insulation material. The secondary use of PPS 17-R-A for its intended purpose, as a heater, is not possible. The volume of foam polystyrene produced varies from 25 to 45 m3 per month. Utilization (disposal) of foam polystyrene waste is an expensive undertaking. Its use as a filler in the production of expanded polystyrene blocks was tested in the factory’s laboratory to produce foam polystyrene concrete with specified physical and mechanical characteristics. The results of testing of expanded polystyrene concrete of classes B2.5 and B 7.5 are presented. It is shown that under the conditions of the reinforced concrete factory technology, the production of polystyrene concrete blocks is possible with the achievement of the design strength. The information presented in the article is aimed at motivating specialists who produce recast concrete to the possibility of using foam polystyrene waste for low-rise construction. Keywords: foam polystyrene, ecology, energy efficiency, foam polystyrene concrete, foam polystyrene heat insulation plates, precast concrete.


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