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9 The Theory handbook collects all the information used to be able to use and understand the underlying calculations with regards to Flexible Support.
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13 = [[image:flex 3d.jpg]] =
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15 Figure 1. Excessive schematic representation of a floor slab supported on flexible beams. (F. Lagerström, 2016)
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17 = Calculation of stresses in hollowcore cross sections =
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19 The aim with calculating these stresses is to avoid any cracking within the hollowcore cross sections. There are several different approaches to this, explained in [[FIB Bulletin 6>>doc:Documents.FIB Bulletin 6.WebHome]] and the Finnish Code Card 18. There is also another approach described by T. Roggendorf in his PhD Thesis //Zum Tragverhalten von Spannbeton-Fertigdecken bei biegeweicher Lagerung//, Aachen Technische Hochschule (2010).
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22 |=(% style="background-color: rgb(0, 118, 203); text-align: center; width: 190px;" %)(% style="color:#ffffff" %)Approach|=(% style="background-color: rgb(0, 118, 203); text-align: center; width: 289px;" %)(% style="color:#ffffff" %)Supported by StruSoft Flexible Support
23 |(% style="text-align:center; width:190px" %)[[FIB Bulletin 6>>doc:Documents.FIB Bulletin 6.WebHome]]|(% style="text-align:center; width:289px" %)[[image:yes.png]]
24 |(% style="text-align:center; width:190px" %)Code Card 18|(% style="text-align:center; width:289px" %)[[image:no.png]]
25 |(% style="text-align:center; width:190px" %)Roggendorf, 2010|(% style="text-align:center; width:289px" %)[[image:no.png]]
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27 == Calculation principles ==
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29 The calculation uses stiffnesses of the beam, hollowcore, joint concrete, and screed to calculate the deflection of the beam, causing the stresses within the concrete cross section of the hollowcore.
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31 [[image:1612941171746-908.png||alt="Text"]]
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33 Figure 2. Picture of the shear flow and shear force of the hollowcore cross section ([[FIB Bulletin 6>>doc:Documents.FIB Bulletin 6.WebHome]])
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35 == Properties of different regions ==
36
37 === Beam ===
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39 [[image:Area Beam.png||height="139" width="297"]]
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41 Text
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43 === Hollowcore ===
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45 [[image:Area Hollowcore.png||height="138" width="294"]]
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47 Text
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49 === Core fillings ===
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51 [[image:Area Core fillings.png||height="151" width="305"]]
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54 Core fillings are ignored in the calculation of the stiffness of the composite beam.
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56 They are however considered with the β,,f,,-factor.
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58 (% border="1" class="table-hover" style="width:479px" %)
59 |(% style="background-color:#0076cb; width:264px" %)(% style="color:#ffffff" %)**Slab thickness [mm]**|(% style="background-color:#0076cb; text-align:center; width:51px" %)(% style="color:#ffffff" %)**200**|(% style="background-color:#0076cb; text-align:center; width:49px" %)(% style="color:#ffffff" %)**265**|(% style="background-color:#0076cb; text-align:center; width:52px" %)(% style="color:#ffffff" %)**320**|(% style="background-color:#0076cb; text-align:center; width:58px" %)(% style="color:#ffffff" %)**400**
60 |(% style="width:264px" %)Filling length < 50 mm|(% style="text-align:center; width:51px" %)1.0|(% style="text-align:center; width:49px" %)1.0|(% style="text-align:center; width:52px" %)1.0|(% style="text-align:center; width:58px" %)1.0
61 |(% style="width:264px" %)Filling length at least equal to the depth of the void (h,,c,,). All voids filled|(% style="text-align:center; width:51px" %)0.7|(% style="text-align:center; width:49px" %)0.7|(% style="text-align:center; width:52px" %)0.5|(% style="text-align:center; width:58px" %)0.5
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63 Table 3.2 β,,f,,-factor ([[FIB Bulletin 6>>doc:Documents.FIB Bulletin 6.WebHome]])
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65 [[image:1613030950002-896.png||height="270" width="686"]]
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67 Figure x. Distance h,,c,,.
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69
70 === Joint concrete ===
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72 [[image:Area Joint concrete.png||height="151" width="312"]]
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75 Text
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77 === Topping on beam ===
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80 |(% style="width:141px" %)Case|(% style="width:367px" %)Visualization|(% style="width:418px" %)Properties
81 |(% style="width:141px" %)Beam web is lower than hollowcore|(% style="width:367px" %)[[image:Area topping over Beam.png||height="144" width="306"]]|(% style="width:418px" %)
82 |(% style="width:141px" %)Beam web is higher than hollowcore, but not higher than hollowcore and topping|(% style="width:367px" %)[[image:1613032475294-805.png||height="151" width="320"]]|(% style="width:418px" %)
83 |(% style="width:141px" %)Beam web is higher than hollowcore and topping|(% style="width:367px" %)[[image:1613032557329-497.png||height="155" width="323"]]|(% style="width:418px" %)
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85 Table x. Properties of different cases of topping
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87
88 [[image:1613061430035-125.png||height="341" width="669"]]
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90 Figure x. Definition of b,,web,,, h,,web,,, b,,joint,,, h,,hc,,, h,,topping,, and b,,support,,.
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95 === Topping on hollowcore ===
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97 [[image:Area topping on HC.png||height="140" width="295"]]
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99 Text
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101 = References =
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108 **Contents**
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110 {{toc/}}
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115 {{putFootnotes/}}
Copyright 2020 StruSoft AB
PRE-Stress Documentation