[Timber Design]

By

ACKNOWLEDGEMENT

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible.

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University.

Signed __________________ Date _________________

ABSTRACT

This paper presents the analytical and experimental results of an investigation of a new type of hybrid beam (BLCHP) reinforced in the tensile part by rods made of steel (S), glass (G) or carbon (C) fibre-reinforced polymers. The hybrid beam is obtained by bonding the lamellae of UHPC-SFR to a laminated wood section. The high performance concrete lamellae, which have a compressive strength of 150 MPa and a tensile strength of 15 MPa, are cast in layers varying in thickness from 1 to 4 cm. The Young's modulus of UHPC-SFR is approximately 50,000 MPa. To increase the ultimate bearing capacity, FRP rods can be used in the tension part. The UHPC-SFR layers are internally reinforced with steel or FRP bars to increase the tensile strength of the bottom portion of the hybrid beam. The wood-concrete composite beams used in this research were fabricated using the bonding connection, as mentioned above. A primer was applied to the top and bottom faces of the glulam to improve bonding. The concrete plank was sandblasted before bonding. The epoxy for bonding was first applied to the concrete plank and then to the glulam timber. Pressure was applied for 24 h and the curing temperature was maintained at 20 °C for 7 days. The bonding allows to obtain a perfect adhesion between each layer and to assume a continuous strain distribution between layers as shown by Schäfers and Seim. The objective of the modelling was to optimise the configuration of the section by selecting the most appropriate thickness for the UHPC and wood layers thereby increasing the bending stiffness and the ultimate load capacity of the section over normal timber glulam structural elements of identical overall dimensions. The experimental testing was performed on beams with a 2 or 5.1 m span. This work confirms the good performance of this innovative hybrid structural configuration.

List of Abbreviations

TABLE OF CONTENTS

ACKNOWLEDGEMENTII

DECLARATIONIII

ABSTRACTIV

LIST OF ABBREVIATIONSV

CHAPTER 1: INTRODUCTION1

Background Of The Study1

Problem Statement1

Research Aim2

Significance Of The Study2

CHAPTER 2: LITERATURE REVIEW3

Wood: The Inception Of Civilization3

Perception Of Wood Material4

Usage Of Timber In Construction And Design5

Composition And Structure Of Wood7

Macroscopic Structure8

Marrow9

Heartwood:9

Sapwood:10

Cambium:10

Liber:10

Crust:10

Woody Radio:10

Annual rings:11

Cross Laminated Timber (Clt): The New Black In The Market11

A Complete Building System14

Uncomplicated Manufacturing15

Concrete As A Structural Material18

Differential Movements In A Timber Multi-Storey Hybrid Building22

CHAPTER 3: METHODOLOGY27

Research Design27

Literature Selection Criteria27

Search Technique27

Keywords Used28

Analytical Modelling28

Material Properties30

Calculation Procedure32

Failure Criteria36

CHAPTER 4: CASE STUDY39

Experimental Investigation Of Infilled Reinforced Concrete Frames With Openings39

Experimental Program41

Test specimens41

Material properties43

Test setup and instrumentation44

Experimental Results45

Interpretation Of Experimental Results47

Load-displacement envelopes47

Stiffness48

Ductility49

Energy dissipation capacity49

Degradation from cycling50

Analytical Modeling Of Masonry Infill With Openings50

CHAPTER 5: DISCUSSION AND ANALYSIS54

Experimental/Theoretical Comparison54

Bending Stiffness And Deflection ...