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CONNECTION BETWEEN SIMPLE SPAN PRECAST CONCRETE GIRDERS MADE CONTINUOUS-EMBEDDED CONNECTIONSDIMMERLING, AMY JO 11 June 2002 (has links)
No description available.
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Experimental Evaluation Of A Precast Concrete Beam-To-Column Prototype Design Under A Column Removal ScenarioTorres Alamo, Jorge Omar 06 May 2017 (has links)
Precast concrete multistory buildings are used in an attempt to optimize the available construction space and reduce costs. However, little is known about predicting their capacity in a brittle response mode due to the sudden loss of a critical element that could induce a Progressive Collapse Scenario. Therefore, the National Institute for Standards and Technology (NIST) developed an explicit approach in the design of precast concrete systems that is intended to mitigate a progressive collapse by enhancing the rotational capacity of joints and the robustness of the structural system. A full-scale experiment was conducted to investigate the structural performance of a prototype design under a column-removal scenario. The test assembly frame, consisting of three columns and two beams, was subjected to a displacement controlled vertical force acting at the center to characterize the failure modes and collapse mechanisms. Brittleailures of critical structural elements were observed and significantly impacted the performance.
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Design and construction preferences for connections in the precast concrete industry of South AfricaMostert, Louwrens Hubert 12 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Precast concrete has been used for decades in the construction industry, locally as well as
internationally. Rapid urban development and the need for shorter construction periods for building
and infrastructure projects have however encouraged more use of precast concrete construction. The
improved speed of construction, high quality and less labour requirements that precast offers makes it
an effective type of construction method for modern development. The utilization of various precast
concrete systems has been frequently used in the international construction industry, making it a very
popular construction method.
It was however found that one of the major drawbacks or concerns with the use of precast concrete is
the connections between the precast elements. In-situ construction does not have this problem, because
it is designed to a monolithic structure or building. It was identified that if the connections in precast
buildings or structures are designed or constructed in an insufficient way, it can lead to severe
structural problems and even failure. This highlights the importance the design and construction of
precast concrete connections have on the overall stability, strength and robustness of the structure.
Precast concrete buildings are not merely separate precast elements, connected together to eventually
form the same principals of in-situ construction. Precast concrete and connection design is considered
to be a specialist field and requires the sufficient expertise and knowledge to understand the structural
system and all its different aspects.
The precast connection’s function is not merely to transfer loads, but also to develop continuity and
ensure monolithic behaviour of the entire precast concrete structure (Englekirk 2003). The most
important or desirable structural functions of precast connections are; (i) direct transfer of loads (load
paths and flow or forces), (ii) develop structural continuity and integrity, (iii) distribution of
concentrated loads, (iv) allow for movements and unintended restraints and lastly to (v) ensure
efficient rigidity and robustness for the connection. It can be seen that there is many factors that
contribute to the overall design and construction phases of precast concrete connections.
The aim of this study is to identify and investigate aspects that influence the design and construction
of precast concrete connections. This study will mainly focus on precast concrete and precast
connection preferences of participants in the South African construction industry. During this study,
industry participants (contractors and consultants) were asked to identify certain aspects and concerns
associated with precast concrete and precast connection construction. These answers were used to
develop guidelines and preferences that can be used by industry participants to improvise and
effectively manage the precast construction, mainly focussing on the connections between the precast
elements. / AFRIKAANSE OPSOMMING: Voorafvervaardigde beton word al vir dekades gebruik in die konstruksiebedryf, plaaslik sowel as
internasionaal. Vinnige stedelike ontwikkeling en die behoefte vir korter konstruksie tydperke vir die
struktuur en infrastruktuur projekte het egter die gebruik en implementasie van voorafvervaardigde
beton konstruksie laat toeneem. Die verbeterde spoed van die konstruksie proses, 'n hoë gehalte
produk en minder arbeid vereistes wat voorafvervaardiging bied maak dit dus 'n effektiewe tipe
konstruksie metode vir moderne ontwikkelings. Die benutting van verskeie voorafvervaardigde beton
sisteme en elemente word reeds herhaaldelik gebruik in die internasionale konstruksiebedryf, wat dit
vervolglik ʼn baie populêre en effektiewe sisteem maak.
Dit is egter bevind dat een van die groot struikelblokke of probleme met die gebruik van
voorafvervaardigde beton is die verbindings tussen die voorafvervaardigde elemente. In-situ beton
konstruksie het dus nie hierdie probleem nie, want dit word ontwerp om 'n monolitiese beton struktuur
of gebou te vorm. Dit was immers geïdentifiseer dat as die verbindings in ʼn voorafvervaardigde gebou
of struktuur, ontwerp word deur ʼn ontoereikende manier, dit kan lei tot ernstige strukturele probleme
en selfs strukturele faling. Dit beklemtoon dus die belangrikheid wat die ontwerp en konstruksie
proses van voorafvervaardigde beton verbindings het op die algehele stabiliteit, sterkte en robuustheid
van die struktuur. Voorafvervaardigde beton geboue en strukture kan nie slegs beskou word as aparte
voorafvervaardigde elemente wat met mekaar verbind word om eventueel dieselfde beginsels van insitu
konstruksie te vorm nie. Voorafvervaardigde beton en verbinding ontwerp word beskou as 'n
spesialis veld en vereis dat die ontwerper die nodige kundigheid en kennis van die strukturele stelsel
en al sy verskillende aspekte verstaan.
Voorafvervaardigde beton verbindings se funksie is nie net om toegepaste kragte oor te dra nie, maar
ook om strukturele kontinuïteit te ontwikkel en te verseker dat monolitiese gedrag gehandhaaf word
vir die hele voorafvervaardigde beton struktuur (Englekirk 2003). Die mees belangrike strukturele
funksies van voorafvervaardigde beton verbindings sluit die volgende in; (i) verseker direkte oordrag
van toegepaste kragte (vloei van kragte), (ii) ontwikkeling van strukturele kontinuïteit en integriteit,
(iii) die verspreiding van puntbelastings, (iv) moet voorsiening maak vir die bewegings in die
voorafvervaardigde element en konneksie self en laastens (v) verskaf doeltreffende rigiditeit en
robuustheid vir die konneksie sone. Dus kan daar afgelei word dat daar baie faktore is wat bydra tot
die algehele ontwerp en konstruksie fases van voorafvervaardigde beton verbindings.
Die doel van hierdie studie is om aspekte te identifiseer en te ondersoek wat die ontwerp en
konstruksie van aspekte beton verbindings wel beïnvloed. Die studie sal hoofsaaklik fokus op
voorafvervaardigde beton en verbindings voorkeure van persone in die Suid-Afrikaanse
konstruksiebedryf. Tydens die studie was persone in die industrie (kontrakteurs en konsultante) ook
gevra om sekere aspekte en kwellings wat verband hou met voorafvervaardigde beton asook die verbindings te identifiseer. Die antwoorde wat verkry was uit die industrie deelnemers kan toepaslik
gebruik om word riglyne en voorkeure op te stel wat vervolglik gebruik en toegepas kan word in die
konstruksie bedryf van Suid Afrika. Die riglyne kan effektief gebruik word om voorafvervaardigde
beton asook die verbindings te verbeter en persone in die konstruksie bedryf in te lig oor voorkeure en
toepassings van hierdie metode.
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