BUILDING CONSTRUCTION 2 (BLD 60703/ARC 2513)

PROJECT 1: SKELETAL CONSTRUCTION - TEMPORARY BUS SHELTER

GROUP MEMBERS:

CHOO ZI ZHAO 0320498

MUHAMMAD ASHROFF 0325736

RAJAN KULANDAYA 0317164

WONG WAN JIUAN 0327173

MUHAMMAD ZAIM 0325930

TUTOR

MS SUJATAVANI GUNASAGARAN

TABLE OF CONTENTS

1.0 INTRODUCTION

2.0 DESIGN ANALYSIS

3.0 PRECEDENT STUDIES

4.0 DESIGN DEVELOPMENT

5.0 DESIGN CONSIDERATION

6.0 JOINTS AND CONNECTIONS

7.0 LOAD AND FORCE

8.0 CONSTRUCTION PROCESS

9.0 CONCLUSION

REFERENCE

APPENDIX

1.0 Introduction

In this project, five of us chose Tetrahedron and Triangular Prism as our

skeletal form to construct our temporary bus shelter in a scale of 1:5.

Although Triangular form is the most stable construction form due to its

inherent structural characteristic, the consideration of using Bamboo in

our design becomes our most challenging decision. Compared to other

construction methods by using nuts and bolts for connections, we are

going to use traditional joints used in bamboo construction to connect

each of the primary and secondary supports, from the foundation to the

roof and some minor materials to enhance its strength, such as concrete

to hold the bamboo’s primary support.

Our decision is to prove Bamboo can be widely used in light construction

such as a bus shelter by replacing materials like wood and metal. By

utilising traditional bamboo joints, its structure also can be easily

dismantled.

01

2.0 Design Analysis

There are two aspects our group looked into before constructing our temporary bus shelter: 1. Form of the bus shelter 2. Material (Focus on Bamboo)

2.1 Form

The reason of choosing Tetrahedron and Triangular Prism to design our bus shelter is based

on the triangle inherent structural characteristic in the form. Compare to square, the end points of

triangle can transfer high amount of forces due to its rigidness without deformation. So, triangles

often used as trusses in bridges or as others support structures in the building.

2.2 Material

Our group chooses Bamboo as our main material for our project to show that the shape and material can perform well together.

Due to Bamboo’s growth cycle, it can grow more than one metre in a single day, and it can reach its maximum height within the first six months. For

Bamboo to be used in construction, it needs 3 years to develop its strengths and five to six years to fully mature. Compare to normal trees’ growth,

Bamboo can be harvested faster and solve the shortage of some materials. Bamboo has its own advantages and disadvantages as follow:

Tetrahedron Triangular Prism

Advantages

Bamboo is an extremely strong fibre

Highly flexible

Low-cost and environmentally friendly

Light weight compared to steel

Shock absorbing and thus earthquake resistant

Bamboo can prevent pollution by absorbing large

amounts of nitrogen from waste water

It also reduces the amount of CO2 in the air

Disadvantages

Joining Techniques are limited however the development of more effective

methods Is still being researched

Flammability Bamboo structures are not fire resistant and the cost of

treatment is high

Bamboo has a round profile therefore connections are pretty complicated.

Bamboo is hollow there is no material to tighten the middle to the cane

Bamboo is not suitable for loads in cross direction because there are no

cross fibres

Bamboo is a natural material that varies in diameter length and quality

according to the climate.

The density of fibres in cross section of a bamboo shell varies with thickness

as well as in height so it is not constant

Bamboo is more prone to insect attacks than other trees and grasses

Correct bamboo to use due

to brownish hue

3.0 Precedent Studies

We got some inspiration from a series of precedents

Bamboo Structure

1. Restaurant at Greenville, Jarkata, Indonesia- DSA+s

We admired the aesthetics of bamboo used and how the bamboo was standing on the

concrete foundation that came out from ground to prevent from water.

The usage of a wide and also high roof for allowing to wind flow freely through the

restaurant. The roof cover also made from bamboo, which is assembled with coupling

system. The system is used for preventing water dripping, and for protecting cracking

which usually happened when bamboo is being exposed directly to the sun.

2. Bamboo Bus Stop, Bombay, India – Indian Institute of Technology

The bus stand was built in a nearby village

We were inspired by the simple, functional and sturdy form, and how a zinc roof was implemented on the bamboo

rafter.

In our case we thought of replacing the zinc roof with a corrugated board to disperse sunlight and increase

brightness in the bus shelter.

3. Bamboo Selection

Bamboo used for construction should be a light brown hue. This ensures that the plant is at least

3 years old

Avoid bamboo that’s cut in spring or early summer these batches are generally weaker due to

increased fibre moisture content

Foundation

Concrete Formula Applied & Concrete mix proportions

Concrete ratio should be as low as workability will allow.

Excess water causes swelling of the bamboo.

High early strength cement is preferred to minimize cracks caused by swelling of bamboo

when seasoned bamboo cannot be waterproofed.

Waterproofing & Strengthening Bamboo

The bamboo trusses are first coated with 2 – 3 layers of rubber tree oil. The oil helps to protect the bamboo from moisture.

Bamboo has to be treated against insect attack these are to be soaked in a solution of borax and boric acid. Fifty grams of each chemical for every litre

of water. Soaking time typically takes 3 days.

another method can be used where the bamboo is soaked in an alum solution for 30 minutes to preserve them for 15 years.

Roof

In our model, we use PVC corrugated cardboard sheet to represent polycarbonate corrugated roofing. The reasons for choosing this material is due to its many advantages:- • Uv resistance • High plasticity • Light and heat resistance (Metallic Sunstop) • Good thermal insulation • Lightweight • Fire resistance • High degree of transparency • Impact resistance and unbreakable • Easy transportation • Virtually Unbreakable

Code Structural(mm) Colour Thickness (+/-5%) Length

A Angular Corrugated (5Grooves)

Brown, Clear,

Metallic

0.8mm, 0.10mm, 0.12, 18mm,

MS-1.0mm 18', 20'

MC Mid-Circular Corrugated (9Grooves)

Brown, Clear 0.9mm 6', 7', 8', 10',

12', 20'

http://www.deskylight.com.my/product-polycarbonate

PVC Corrugated Board to

represent actual material

4.0 Design Development

Initially we had planned to use a cylinder & a rectangular prism as our base forms

We collectively drew some sketches as well as made a few mock up models.

However, we found that it was going to be a tough process to apply bamboo into a cylindrical form structure as bamboo needs to be bent and curved at

times with special machinery

So instead we used more rigid forms such and a tetrahedron and a rectangular prism as they seem easier to work with

Another reason why we chose to work with bamboo is that we wanted to create a structure that is not only made out of sustainable materials but also a

structure that doesn’t depend on a lot of additional materials meaning a structure that depends solely on locking and interlocking joints.

Mock-up

model refined

Initial

scheme

Stage 1 Initial Form of Bus shelter identified some difficulties due to securing the 3 structures together

from shear weight plus too many unnecessary members

Stage 2 Reduced the number of structures down to 2. We found it easier to

work with however in terms of stability it was still pretty bad as well as for the

prevention of rainwater at the back of the structure. This structure was lacking proper space

for the seating as well.

Stage 3

Stability was reinforced after adding horizontal, slanted, benches on either ends of the structure

connected to a third main structure in the middle (which visually shows a division of each structure)

This is a unique feature we considered and reinforced stability greatly. Our final 1:5 scale structure is based on this design

4.1 Technical Drawing and Terminology

Rafter

Sitting Area/ Bench

Batten

Timber Decking

PLAN

FRONT ELEVATION

White PVC Corrugated Board Roofing

Column

Concrete Foundation

Sitting Area/ Bench

White PVC Corrugated Board Roofing

Sitting Area/ Bench

Timber Decking

REAR ELEVATION

Batten

Column

Rafter

SIDE ELEVATION

5.0 Design Consideration

There are a few requirements in the brief to build the temporary bus shelter:

1. Bus shelter should able to occupy 5 people

2. Weather Resistant

5.1 Occupancy of the Bus Shelter

5.2 Weather Resistant

We choose PVC Coruggated Board to represent Polycarbonate roofing. It is because this roofing

system can reduce sunlight and heat, and incresing the brightness inside the bus shelter. Besides, it

is easily to maintain and lightweight.

For the raining, we create 15 degree slope for our roofing slope and decrease the height of the roof to

2.2M. It can use as a stand to avoid the rain.

SUN

6.0 Joints and Connections

Main Structure

Wedge Dowel Chord Bamboo

Roof & Foundation

L Plates Screw Plank

6.1 Bamboo Cut and Joinery Techniques

Bamboo Cuts

Bamboo Joinery Techniques Use of Dowels and Wedges

Splicing Bamboo Pole

In this model, we were using sawing and drilling to make bamboo’s joineries.

Three different cut which are One Ear, Beveled and Flute Mouth were applied in the model.

Joining Two Ear with vertical elements,

which at the part of column and rafter.

Joining bamboo with dowel is to fix the position of the strcuture and also lashing around

it. Inserting wedge between the bamboos is to advoid movement while lashing.

To adding the length of the bamboo,

telescpoe splicing can be applied.

6.2 Bamboo Lashing Techniques

We used the lashing techniques as follow:- Drilled lashing Joint, Pegged lashing joint, Modern square lashing, Diagonal lashing and West country shear lashing

7.0 Load and Force

Bamboos natural ability is having a tensile strength, to create a stable structure, in this category we look into its structure, we formed primary structure

and its secondary structure. For the primary structure, we put two bamboos together acting as a ‘Column’; secondary structure is identified basically

are rafter and batten, which are to support the roof; and also the bench, acts as the connection among the columns’ to transfer the loads.

7.1 Primary and Secondary Structures

PLAN REAR ELEVATION

FRONT ELEVATION SIDE ELEVATION

LEGEND

PRIMARY

SECONDARY

7.2 Load Transfer

Legend

PLAN

SIDE ELEVATION FRONT ELEVATION

8.0 Construction Process

1. Cutting bamboo to create joints

2. Inserting wedges / dowels and lashing

3. Form and connect primary and secondary structures

4. Formed rafter and batten, with PVC corrugated board as roofing sheet

5. Concrete mixing to create foundation pad

6. Constructing timber decking

7. Coat painting 8. Load testing

Then, we are DONE!!!

9.0 Conclusion

Through all the time we spend to construct a Bamboo bus shelter, we realize mock up models and concept drawings are not really to be 100% followed

and assumed. So, to make our group’s bus shelter design’s structure workable, we have research on the connection techniques of the bamboo. From

the structure itself, we found that our bamboo bus shelter is very unique; we are not only using the traditional method to reduce the use of metal bolt

and nuts but also successfully attached seating area as a part of the support structure. However, during the model making, we also realize the quality

of bamboo has to be controlled, or else uneven diameter of the bamboo is affecting the level of the structure. The best part of this project for us in this

group was we finally built a model almost same as our concept design. And we prove, the forms and the material those we choose are able to sustain.

References

1. Appropriate Building Materials: a Catalogue of Potential Solutions, Third Revised Edition (1988). Retrieved on Sept, 2016, from

http://www.nzdl.org/gsdlmod?e=d-00000-00---off-0hdl--00-0----0-10-0---0---0direct-10---4-------0-1l--11-en-50---20-about---00-0-1-00-0--4----0-0-

11-10-0utfZz-8-00&a=d&c=hdl&cl=CL1.1&d=HASH70c81f6386a2600bdfdd3f.3.13

2. http://inhabitat.com/indian-students-make-bamboo-bus-stop/

3. Green, L. (2013, February 23). SCOUT PIONEERING. Retrieved October 02, 2016,

from https://scoutpioneering.com/tag/what-kind-of-rope-for-lashing/

3. Stéphane Schröder. 2009. Bamboo Joints and Joinery Techniques. Retrieved September 30, 2016,

from http://www.guaduabamboo.com/working-with-bamboo/joining-bamboo.

4. Schröder, S. (2016, May 04). Bamboo Lashing Techniques. Retrieved September 30, 2016,

from https://www.bambooimport.com/en/blog/bamboo-lashing-techniques

Appendix

All designs and development sketches

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