Cork Institute Of Technology Construction Essay

This undertaking is based on the analysis and testing of lumber and concrete composite constructions, with peculiar mention to composite floors. Basically the lumber and the concrete is joined together in such a manner that they act compositely together a individual incorporate structural unit By uniting these two person structures together one is able to utilize the best belongingss of each stuff the lumber resists the high tensile emphasiss and the concrete the high compressive strengths. . The two different stuffs are joined together by a shear connection which provides a shear opposition to the concrete uplifting at the lumber interface, and resists any horizontal motion between the stuffs.

TCCS has been by and large used in the past by companies in Mainland Europe when by and large there is a higher per centum of lumber structured edifices. The old lumber edifices may perchance be falling into a province of disrepair. And instead than replace the old joists in the edifice, shear connections are placed into the old joists, the floor back up to lie flush if had started to droop, and a bed of concrete poured onto the bing floor. When the concrete dries it acts compositely with the old lumber joists and one time the acroprops are removed. This new TCCS construction has much enhanced belongingss and features, the shear capacity, sound opposition, heat and fire opposition will all be increased. And the fact that merely a thin sheet of concrete has been used will non truly add a monolithic burden onto the joists.Two different companies are seen as the taking suppliers of “ built to aim ” shear connections, these are tecnaria and HBV.

In the undertaking I appraise both merchandises and utilize one shear connection for usage in the research lab trials ; many other less commonplace shear connections are evaluated and reviewed to derive a certain penetration into utilizing this engineering in a modern society where basically making more for less money is cardinal.The design of a TCCS floor – spreadsheet – specified connectionsTable of Contentss

Chapter 1

Introduction

Introduction

TCCS ( Timber concrete composite constructions ) is basically the planing a timber member in a edifice to defy more burden than it was originally designed to defy, this is done by agencies of pouring a concrete screed on top of the joists so that when they harden the tonss are transferred into the concrete slab which withstands the compressive emphasiss. The concrete and timber act in unison to defy the emphasiss applied, the best belongingss of each stuff are utilised. The Timber withstands the tensile forces applied and the concrete takes the compressive emphasis generated from the flection of the floor. In mainland Europe this has been done to restitute old lumber floors but nowadays companies are bring forthing TCCS floors out of the mill as they are cheaper, lighter and more environmentally friendly to bring forth to other rivals such as hollow nucleus slabs. They besides have the extra benefit of being far easier to put in than dramatis personae in situ floors which require complex shore uping systems. To acquire the lumber and concrete to move in unison shear connections must be provided to fall in the two stuffs together at the timber- concrete interface. There are a really many figure of shear connections available on the market, some of which will be reviewed and described in deepness in this undertaking.

Each if these different connections has a scope of stiffness and burden capacities each of which fundamental for the design of TCCS floorsThe undertaking will affect a survey of the shear connections utilised in the design of TCCS, the concrete strengths and the strength categories of the lumbers. The different types of connections will be reviewed and the strength/weaknesses of each connection discussed with relation to Eurocode 5. Lab trials will be carries out to find the structural public presentation of the TCCS connections considered.

Background

In recent twelvemonth at that place has been successfully increased demand for larger, bigger and in general better edifices. In response to this slabs need to cross increasing lengths but with this addition of length a relative addition in deepness besides needs to be seen. Traditionally the reply to this would hold been to merely supply the slabs no affair of cost, but in recent times a better attack to edifice design would be to do the slabs beams and columns dilutant and igniter, non merely does this lessening the overall weight of the edifices but it reduces costs as by and large a measure surveyor will monetary value stuffs per weight. Reducing the weight of these edifices even more is seen to be the following measure, This would hold been achieved by utilizing hollow nucleus precast concrete slabs in design, but it is non ever practical to utilize these.

This leads me on to the purpose of my undertaking, to supply an option, lighter stronger floor which can be produced at a cheaper cost and compare it to some off the shelve unitsIn the two decennaries timber composite building has found a really many structural applications in modern edifice building, renovation of old lumber floor, deck systems for Bridgess and even preformed composite floors built in mill. They are really popular along the European mainland merely due to the easiness of entree to cheap lumber as a structural stuff. Despite all of these advantages though most of the Irish and UK building industry do n’t cognize excessively much about the usage of TCCS.

Or the design of these constructions and it is this fright of the terra incognita, which makes interior decorators wary of depending on little shear connections to keep up a edifice. Hopefully upon the debut of Eurocodes and peculiarly Eurocode 5, will alter the interior decorators demeanour towards advanced stuffs such as this, and particularly with clients looking for cheaper signifiers of building, the popularity of TCCS should better.Concrete composite building is the thought behind doing an single structural unit out of two or more different structural stuffs, by and large these two stuffs will hold different belongingss but when bonded together as a individual component will take on the best belongingss of each stuff, for illustration concrete has great compressive emphasis defying abilities, but merely does n’t execute every bit good in tenseness. Steel Acts of the Apostless good in tenseness and compaction but it is sometimes inefficient to utilize a solid steel beam so it makes sense to bond steel strand into a concrete beam, therefore utilizing and achieving the best belongingss of each, stuff. In composite building each single stuffs belongingss are used to achieve the best construction which will execute a certain undertaking, etc. execute good in bending, being more cost efficient, act stiffer, less noise transportation.etc.

There are infinite illustration of composite building seen today, precast hollow nucleus slabs with steel strands weaved into the mix, steel beams with concrete slabs joined together, timber beams with steel decking and slab dramatis personae on top etc. he most widely available signifier of composite building is strengthened concrete. E.

g. concrete beams with steel bars placed into the wet concrete to defy tenseness while the concrete resists the compressive forces. As newer engineerings come on the market more advanced utilizations are found for stuffs such as polymers being used in building

Aims and Purposes

The aims that have been given in this study were portion of the undertaking proposal, but in the involvements of to the full understanding this undertaking on TCCS a farther in depth analysis of concrete composite floor is required instead than That is specified, This includes giving a clear and prompt description of TCCS, This description will give demo how TCCS performs structurally and depict the advantages and factors ( dimensions, shear strengths Numberss of connections etc. ) that consequence component.

This research will be backed up by work done in the research lab where trials will be carried out to demo comparings between variant burden instances. One of the chief aims of this undertaking will be the testing and specifically the testing of the shear connections which provide the bond between the concrete and timber interface. The beams assembled will be tested by analyzing how they react under known burden conditions, comparings will so be drawn to the theoretical warps calculated utilizing the excel spread sheet created for this intent. The beams burden bearing capacity will besides be compared to the burden transporting capacity of a lumber merely beam which is TCCS free. This aims to turn out the effectivity and lastingness of a TCC floor.Figure 1

Outline of Project and research methodological analysis

To research the undertaking while besides paying attending to the purposes of the research stage a figure of research methods have been used to day of the month. The cyberspace is likely the 1 that has been the most utile while besides the library database In CIT was a welcome add-on to happening mention paperss and published literate that was slightly specific to the undertaking.

The IHS database was besides used to beginning the relevant codifications of practise and certification for the building and analysis of shear connections specific to my undertakinghypertext transfer protocol: //ars.els-cdn.com/content/image/1-s2.0-S1296207412000933-gr5.jpgFigure 1

Chapter 2

Timber-Concrete Composite Structures

Literature Review

The Masterss thesis by jjorg

Function of a timber-concrete complex

library database

Advantages of the timber -concrete composite system

As the proprietor of a edifice by utilizing a TCCS construction you can be safe in the cognition that you are basically continuing the bing construction of the edifice as it combines the best belongingss of strengthened concrete and lumber joists in a lightweight bundleBy utilizing TCCS sound qualities and sound insularity is improved, this coupled with fire protection. In a fire state of affairs the concrete and lumber work efficaciously together while each functioning an single intent. The concrete Acts of the Apostless as an impermeable barrier by halting fire from traveling to one floor to the following piece when the lumber ignites the borders char and provide insularity to protect the nucleus of the beams and shear connections from the utmost temperatures experienced. This allows the construction to stand for longer in an exigency state of affairs.

The Timber concrete sturture besides improves sound insularity camaped to to pure structural timberwork sound bounds of 30-67db can be achieved.The cost nest eggs shown in comparing to a dramatis personae in situ concrete floor guarantee savings up to 40 % and even more in refurbishment undertakings. Coupled with cheaper constructing the composite construction can get by with higher working tonss and possible depending on the burden provide plenty load capacity to cover with a alteration of usage to the edifice itselfSimply from an ecological point of view it makes perfect ecological sense, Timber is the lone major constructing stuff which is genuinely sustainable. The same floor being cast in suit would hold a immense ecological impact due to the sum of C created when doing the deep concrete slabs. Both steel and concrete would be serious subscriber to the crbon footp [ rint of a undertaking “ The sum of CO2A emitted by the cement industry is about 900A kilogram of CO2A for every 1000A kilogram of cement produced ” ( ^ Mahasenan & A ; Steve Smith, 2003 )In the instance of a renovation undertaking its makes fiscal sense to reenforce the bing lumber floor. Removal of the bing joists and the instialltion of concrete constructions is really expensice, this is avoidided by mean of utilizing aa TCCS system. The creaking and motion of bing members is besides eliminated when repairing the joists by agencies fo a shear connection. This besides elimantes the extra cost of holding to acquire rid of anad dispose the the stuff removed if one had to gut the bildingWhen the concrete is poured in situ straight on top of the lumber floor ing the lumber hence acts as a perment formwork as the concrete is bount between the two materioals.

This type of cinstructuin is much faster than cheap Er than usually puting acroprops to keep up a dramatis personae in situ slab when the formwork has to be removed one time the concrete has reached a sufficient strength. hypertext transfer protocol: //www.answersingenesis.org/museum/images/docs/slabpour7.jpghypertext transfer protocol: //www.asme.org/getmedia/8683e36d-52c8-4d17-84bc-9cba7aa28bae/pouring_concrete.jpg.

aspx? width=340In strengthened building usuall 35 % of the concrete lies below the impersonal axix, This concrte is in the tensile zone which by viryue of the fact that concrete has minimal tensile strength means that the concrete merely acts as a dead burden. TCCS reduces and eliminates this inordinate dead burden as the concrete all lies in the compressive zone of the TCCS floor where all its strength is used. This system is far more efficient in comparisomn to a dramatis personae in situ slab which has a monolithic C footmark.Timber concrete composite floors have a greater consequence on the entire stableness of the edifice due to them holding such high in plane rigidness. This leads to the assumpition athta the rigitdy can be assumed infinite and this is an of import design factor that make their usage popular for edifices in countries where seismal activity and temblors are common.The ashtetical visual aspect of lumber flooring is far more beautiful and asteciallly delighting than concrte flooring, It has a natural heat and character that is 2nd to noneit is one of the most poplular picks for flooring and for good ground, Nothing beats the beauty of timebr on the side of a house and is of course a much more friendly stuff than steel or concrteTimber flooring is one of the most popular and abiding picks for flooring and for good ground. Nothing beats the beauty of a wooden floor in the place and lumber floors suit all manners of places from traditional right through to extremist modern.A There are different types of lumber shocking available to you and some of these include laminates, bamboo, solid lumber, or engineered timber.

A Depending on the type of flooring, it can be nailed straight to carriers and joists, or laid over bing floors.hypertext transfer protocol: //www.wales-holidaycottage.com/images/gallery/full/2010062120071112.jpglibrary database

Shear connections

library database

Adhesive materials

Adhesive materials are an alternate solition to utilizing mechanicical connexions in the interface between the concrte and the lumber beam, Efficaciously the the adhesive achives its connexion by adhering the two stuffs together, by and large the contact country of the connection will be the full surface country of the concrete slab wheras with a steel shear connection you would hold a tony shear connexion country in comparision tio the country you are adhering together. One advantage to utilizing this typr of connection is that the shear and bending forces will be distrubiued absolutely equally throught the cross sectional country of the floor. An adhesive connection ensures that there is no comparative movemen between the interface and this guarantees a igh stiffness modulus and henceforth a lessening in warps.

Althought this is an advanget to an adhesive connection few jobs still exist which cut down the populatiry of adhesives in comparing to mechiancal connections. Once a little sum of faux pas occours between the interface the bond will interrupt and the system no longer works, it reverts back to two indibidial members moving not compositly and do the beam to perchance neglect. A better more utile solution would be to utilize a mechanical connection in combination with the adhesiveFigure 2 Continuous glued in-plate connections

Dowel type Fastners

The basic thought behind dowel type fatners is to infix them half manner into the wooden beams, a concrte screed is so poured about and on top of the connections that are extededed upards. Nails, boltsbars and prison guards are all anysled and classified as joggle type connectors The concrte is allowed set and remedy. Once the concrete has set the connections will reassign the forces so that there should be no faux pas between the stuffs and bond sould occour so that they act in brotherhood. For analysis purposes the joggles should be analysed as non being stiff.

Ie provide a minute release at the location if one was analysisng the construction in staadpro. These dowel type connections need to defy high shear forces at the interface which could do the connections to merely shear in half. The burden capacity of the subdivision can be increased by diminishing the infinite between each connection. One disadvantage to this though is that this leads to higeher costs as more connections will be needed.Figure 2 Dowel type connections: a ) nails B ) screws degree Celsius ) glued rebar vitamin D ) prison guards inclined

Design process of a timber-concrete complex

library database

Historical background

During the 1940 ‘s the first of all time design theoretical account for composite beams was created as consequence of a series of little graduated table trials in the United Stas. 10 old ages subsequently two matameatics of Thursday name Mohler and Newmark propsed a additive theoretical account for ciphering flexing trial consequences. They based their work on proveriously derived equaions of equilibrium which was able to take into history interlayer faux pas between the interface of the two affiliated mateirals connected mechanicaly.

This theoretical account is know as of today as the y- method was originally intended to be used for merely supported beams. Then in the ealrie 80 ‘s Goducky proposed a theoretical account which which was capable of takeing interlayer faux pas into history but besides was able to account offor long term affects by presuming some long term diminutions, eg long term weirdo and deteriosation of the alastic moduli of the stuffs.The first efforts to unite wodd and concrete together automatically occoured in the earlys 1920 ‘s – 30 ‘s, Otto C=Schaub was the first discoverer yto apply for a patent that was a TCC component in 1939 Then in the 1960 the first undertaking was completed utilizing Timber concrete composite elements. Its was called Hotel Zum Guten Hirten ” It was an old hotel where the floor was after detioriating, in a n attempt to reconstruct it a concrete floor for cats in situ on top of the exhisting joists to heighten its public presentation. Once Goduky presented his deisgn theoretical account in 1984 the usage of tcc as a engineering became more widespread. When more trials were completed that clip they showed that the composite action was able to increase the ovwerall burden capacity of the construction by a factor of 2.5.

Then in 1985 a new fastner known as a two-base hit headed prison guard was invented for the primary usage in TCC systems. A Glued connexion system wasintroduced in 1993 by Bathon to supply a stiffconnexion between lumber and concrete. Then in 1993 in the Persian gulf lumber Bridgess were covered with concrete to protect them from hot and humid environmental status.

This prevented the lumber beams from decomposing, But when Saki demonstrated that by utilizing steel nails bolted in at 45 grades to adhere the concrte and the lumber together a composite action was achived which lead to a beter and stonger deck system.In 1994 more research was done by dienel who investigated fire insularity belongingss of tcc sturctures. His work besides covered the effets that TCC had on sound insularity and the belongingss of it. The in 1197 Meierhofer showed in his work that by put ining the bolt connectros at an angle to the interface the burden capacity of the subdivision and the stiffness of the member can be increased. . In 2003 Fagicomo and Ceccotti investagted the longterm behavior of TCCS with respects to crawl, hapless environemtal conditions and skrinkage over clip.

Uses of TCCS

New construtions

Given the advantages that TCCS seem to hold over precast elements as shown in Mistake: Reference beginning non found It would be good deserving look intoing the possiblility of mass prodiucing TCCS floor for the irhish constructuiin industry. Clearly it has been shown to be easier to put than a dramatis personae in situ floor and potentially would be produced in the same manner that prestressed beams are.

These floors could perchance be cast offsite and delivered on site already at 28 twenty-four hours strength and earnestly cut down on building clip. hypertext transfer protocol: //www.uni-stuttgart.de/ke/img/Forschung/Info/M8-2.jpgFigure 2 Pre Cast Slab Stored Off Site

Old Bridgess

Renovataion of olf timber flooring/ joists

How it worksPOSITION FO NEUTRAL AXISShrinkingTEMPERATIRE CHANGECREEP AND RELAXIONSUND INSULATION PROPERTOIES

Survey of tried shear-connectors

library database

Nails

library database

SFS-screw ( VB 48-7,5×100 )

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8 Dimple/plug reinforced with slowdown prison guard… ..

. … … … … … … … … … … … … .. 232.3.9 Dimple/plug reinforced with steel pipe… … … … … … … … … … … … … … .. 242.3.10 Dimple/plug reinforced with slowdown prison guard and steel pipe combined ( CHS ) 242.3.11 Punched metal home base fasteners ( Nail-plates ) … … … … … … … … … … … … 252.3.12 Steel brace ground tackle… … … … … … … … … … … … … … … … … … … … … … … … … . 262.3.13 Framing bracket… … … … … … … … … … … … … … … … … … … … … … … … … … . 272.3.14 Universal column ( UC ) … … … … … … … … … … … … … … … … … … … … … … .. 272.3.15 Shaped perforated steel sheet… … … … … … … … … … … … … … … … … … … .. 282.3.16 Steel mesh… … … … … … … … … … … … … … … … … … … … … … … … … … … … … .. 292.3.17 Adhesive… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … .. 302.4 Survey of presently employed timber-concrete composite solutions… .. 312.4.1 The HBV-system… … … … … … … … … … … … … … … … … … … … … … … … … … . 312.4.2 M-section-system solution… … … … … … … … … … … … … … … … … … … … … . 312.4.3 The SEPA 2000-system solution… … … … … … … … … … … … … … … … … … . 33

Evaluation of timber-concrete composite solutions

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General

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Execution

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Testing

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General

Fabrication of beam

Beam layouts

Radio beam 1

Radio beam 2

Radio beam 3

Preparation of lumber

Preparation of concrete

Concrte regular hexahedron trial

Making and hardening of concrete regular hexahedrons

Testing regular hexahedrons

Concrete regular hexahedron consequences

Trial Consequences

Beam 1 warps

Beam 2 warps

Beam 3 warps

Beam 2 V 3

Graph of differneces between 1 and 2

Timeber merely beam 3 V composite beams

Calcualtopn od theoretical warps

Theoretical deflectoions vs existent deflectiosn

5.5.1 Case 1: tecnaria… … … … … … … … … … … … … … … … … … . 625.5.2 Case 2 HBV system… … … … … … … … … … … … … … … .. 73

Execel spreadsheet

INsturcuons in usage

Testing plan

Coach screw connectord

Beam layot

Conclusions & A ; Discussion

Mistakes

In manufactuee

Mistakes in texting of bneams

Mistakes in alculation of theoretical warps

Reccomendations

Table Of Figures