The Effect of Precast Concrete Practices on Commercial Building Productivity in

Comparison to Cast-in-situ Techniques and the Restraints of its use in Brisbane

Author: Tosca Goldberg – N8879176

Academic Supervisor: Duzgun Agdas

To satisfy BEB801 as part of the Bachelor of Engineering (Civil and Construction)

To determine why prefabricated concrete methods are not the predominate choice in Brisbane and the effect of this on commercial construction efficiency.

Research Aim

The following limitations have been identified as a result of this research:

1. Time constraints

2. Financial constraints

3. Difficulty in gathering meaningful information through phone interviews

Research Limitations

Defined as concrete that is cast in a location that differs from the concrete’s final position in the finished structure

Two types of precast:

Off-site casting

Produced in controlled factory environment

• Placed into adjustable moulds

• Concrete is vibrated then cured

• Transported from factory to site

On-site casting

• Common elements: walls, beams, slabs, columns

• Poured directly at project site

• Referred to as tilt up panels

Precast Concrete

Defined as concrete that is transported in a liquid state, generally as ready-mix and deposited into removable forms where it becomes part of the structure

Dates back to 3000 BC construction of Egyptian pyramids

Three distinct steps in the process:

1. Placing formwork

2. Placing reinforcement

3. Pouring the concrete

Cast-in-situ Concrete

International Precast Use…

Europe Following GFC in 2008 and downturn of world economy, precast use declined 38%

from 2008 to 2013

Germany is at the forefront in terms of production within Europe

In 2013, 5.18 billion pounds produced (10.11 billion AUD)

Germany alones precast production is three times more than that of the UK

United Kingdom Dates back to early 20th century

Following WWI and WWII was housing shortage and push towards precast begun

Off site construction approximately $4-6 billion per year and accounted for 2% of the market

Increase in market share of 25% per year

Gulf Cooperation Council Political and economical alliance of the following:

1. Saudi Arabia

2. Kuwait

3. United Arab Emirates

4. Qatar

5. Bahrain

6. Oman

Hosting worldwide events such as FIFA World Cup 2020 and Expo 2020

Benefits of precast are well established

127 major precast companies that are driving the precast industry

Mid 2011, precast contributed to 30%

MAPEI worldwide leader in precast

North America First indication occurred in 1907 through Walnut Lane Memorial Bridge

Prior, precast virtually unknown yet today not uncommon

Recent development by AltusGroup who designed ARCIS ultra-thin panels

ARCIS panels reduce cladding weight by 90% yet preserves durability and aesthetics

National Precast Use…

New South Wales A lot of precast use in NSW – particularly Sydney region

Laing O’Rouke at the forefront and pioneers of offsite construction

Recently developed Design for Manufactured Assembly (DfMA)

Used new precast innovation to construct the Clinical Services Building as part of the Blacktown Mount Druitt Hospital expansion

Lendlease set to open 150,000 square meter factory in Sydney

Investment cost of $15 million

Intention to produce $1 billion worth of prefabricated material over next 5 years

Victoria Over the past decade, Melbourne’s central business district has transformed from

unappealing prefabricated buildings

Precast panels were once thought of as unappealing with the negative connotation of poor design

Precast now shifted to become an integral part of construction

Beginning to realise:

1. Aesthetic capacity

2. Cost Savings

Precast Hindrances…

Prep School Capital Works Project (Australia) Managed by Queensland Department of Public Works

Project to build 400 new classrooms along with a similar amount of refurbished classrooms for the new prep year introduced in Queensland

Issues encountered:

1. Managing logistics

2. Initially more cost effective, however overall cast-in-situ cheaper

3. Concern labour market would restrict project timetable

Skilled Park (Australia) Located in Robina on the Gold Coast

Precast concrete plats manufactured off site

Were able to produce 24 plats per day

Issues encountered:

1. Cannot fix design errors easily later

2. Appropriate labour and workshop space difficult to secure

3. Essentially no flexibility to adjust the elements on site

4. Quantity of engineers comfortable designing precast components is limited

5. Fastenings are substantial cost of precast elements problems arise if engineer does not have solid understanding of precast

Hong Kong Research conducted by Griffith University into Hong Kong’s precast hindrances

Surveyed over 200 parties including government departments, developers, consultants, main contractors and sub-contractors

Results showed the following hindrances (in order of biggest factor):

1. Inflexible changes of design

2. Lack of background research

3. Higher initial construction cost

4. Time consuming during design phase

5. Lack of consideration to advantages of precast

6. Limited space for precast components

7. Lack of aesthetics

8. Leakage problems during jointing

9. Lack of experience

10. Lack of demand for precast components

United Kingdom Study carried out in 2007 in association with Cooperative Research Centre for

Construction Innovation

Investigated hindrances faced within the United Kingdom in the shift towards off site manufacturing

Precast uptake was limited and only accounted for two per cent of the $209.16 billion construction sector

Main reason established was lack of research and knowledge about precast benefits

To drive precast, the following funding occurred:

1. $9.8 million by Government

2. $19.6 combined Government and industry

South Africa Rapid growth has been experienced within the South African construction sector over the

past decade at a rate of approximately 5% since 2007

Typical high-rise project ranges from two through to five years duration in terms of building time

Presently, cast-in-situ is a very common method used amongst South African construction companies

The technical and economical expansion of the industry has steered engineers to search for new methods that are both efficient and effective saving both time and money

Precast Advantages Research…

Melbourne Water Headquarters (Australia) Located in Melbourne’s ‘Digital Harbour’ precinct

Required to meet budget and program targets with strict construction timeline

Key advantages are as follows:

1. Aesthetics

2. Time saving

Pullman Hotel New South Wales (Australia) 5-start Pullman Hotel located at Sydney Olympic Park

Features 212 rooms across 16 levels

Emphasis was placed on safety during construction

Key advantages are as follows:

1. Safety

2. Reduce labour

3. Time savings

4. Aesthetics

Tesco Supermarket (United Kingdom) Used alternative approach and had precast beams transported to the site where they

were raised into correct position

Key advantages are as follows:

1. Less highly skilled operations

2. No effect on inclement weather

3. Safety

Precast and Productivity in Commercial Building Range of factors which contribute to productivity on building construction

Labour Efficiency

One of the main factors effecting productivity

Monash University investigated the construction productivity of pre cast and cast-in-situ methods within the Malaysian market

Study focused on four structural components, beams, columns, walls and slabs

Collected data through questionnaires, interviews, observations, video camera footage and other secondary data

Results showed productivity of precast methods is consistently better than that of cast-in-situ methods in regards to labour

Transportation

The route, traffic, road conditions and weight of load can all have a negative effect on the productivity

In regards to commercial construction in Brisbane, the majority of projects are located within the central business district meaning precast facilities are on the outskirts

Also limitations imposed by the Australian government and Department of Transport and Main Roads.

Primary Research and Results…

Participants Represent both precast companies and construction companies who either supply or

build within the Brisbane region

Precast companies interviewed:

1. Brisbane Precast

2. Austral

3. Australian Quality Precast

Construction companies interviewed:

1. TMP Builders

2. Total Constructions

3. Watpac Limited

Procedure

Data collected through phone interviews following a questionnaire

Interviews ranged from 10 through to 30 minutes with a median time of 14 minutes

Whilst the interview was being undertaken, the same researcher transcribed the verbal responses

Results – Precast Company Responses

Precast Demand Trend (Past 5 years) – Has it increased?

Yes, precast demand has increased (66.6%)

No, precast demand has decreased since mining boom and now is steady (33.3%)

Reasoning Behind Lack of Uptake

The following reasons were identified across the three precast companies:

1. Too expensive to justify

2. Architect and engineers prefer traditional method and design to this

3. Different culture compared to Sydney/Melbourne

4. Brisbane not large enough city for time to be at forefront of importance

Results – Construction Company ResponsesPredominate Methods Used

Combination of precast and cast-in-situ (100%)

Reasoning Behind Combination Use

Project specific

Design engineers choice

Precast used for simplicity and fast build time

Precast Use Issues

High project management costs

Initial expense

Struggle to find correct trades

Stretch out in lead times

Difficult to rectify mistakes

High risk during erection process

Precast Advantages…

Construction Time

Speed-to-market is a key advantage and relates to the time that elapses between the beginning of the concrete process and the final placement

All three of the construction company respondents answered ‘yes’ to is precast cost effective?

Melbourne Water headquarters and Pullman Hotel in Sydney showed reduced construction time was a major advantage when utilising precast concrete methods

Sustainability/Environmental Impact

Construction industry moving towards reducing carbon footprint

Many companies looking to create more sustainable structures

National Precast Association of Australia lists following reasons making precast the sustainable choice:

1. Precast is locally manufactured meaning local products and using industry’s most ecological and economical practices

2. Precast’s accurate manufacturing to design causes a massive reduction in

construction waste

3. Precast allows fast, cost-efficient construction resulting in minimal site disturbance

Aesthetics

Once seen as a disadvantage and aesthetics being very limited

Precast has come a long way and many are now starting to see the potential

Variety of shapes, colours, textures and finishes can be produced

Melbourne Water headquarters and Pullman Hotel in Sydney reinforced the extraordinary aesthetic results

Reduced Labour and Safety

Labour skills required are more intensive when using precast

Overall amount of labour required on precast projects is significantly lower

Due to concrete not being cast-in-situ, it eliminates the need for many workers on site, hence increases the safety on site

Precast Disadvantages…

Perceived Costs

Imperative to distinguish the difference between the terms ‘cost’ and ‘price’ when discussing which method is the most effective financially

Price can be defined as the amount customers pay for a product

Cost can be defined as the amount spent by a business making a product

Disadvantage reinforced through responses received by construction companies regarding precast being cost effective

66.6% responded no, meaning it is clear that the entire costs of precast use is not well understood and instead determined at the initial amount

Transportation and Handling Costs

When handling precast concrete elements, workers must be extremely careful to avoid causing any damage that may compromise the integrity of the components

Due to being cast off site, the elements must be transported to site

Challenges faced from transportation are:

1. Route

2. Traffic

3. Road conditions

4. Weight of load

5. Size of elements

Modification Limitations

Study by CIB World Building Congress looked at disadvantages of precast concrete construction in high-rise buildings within Hong Kong

Identified a disadvantage that the possibility of late change in the design was very limited

Thomas Menso from Watpac and Anthony Collins from TMP Builders both raised the issue of the difficulties associated with changing a design following the initial design

Skilled Labour Required and Associated Costs

Interview with Mathew Dorge from Total Constructions highlighted the issue of lack of skilled trades that existed when sourcing for precast projects

Research by Dr Philip Alviano investigated and identified the job roles and their additional skills required by the prefabrication industry

Jobs that require further skills for precast use are as follows:

1. Designers

2. On-site assemblers

3. Manufacturing Engineers/Technicians

4. Occupational Health and Safety Officers (OH&S Officers)

Conclusion…

Anecdotal Mentality

Many within the construction industry approach building with an anecdotal mentality, meaning decisions being based on personal accounts rather than facts or research

Arthur Taborky, Brisbane Precast said “many designers and engineers have the mentality that precast is more expensive, yet fail to take into consideration the entire cost”

Perceived costs with figures provided by the National Precast Concrete Association that shows precast is in fact more cost effective when all factors are considered

Lack of Research/Funding

United Kingdom in comparison to Australia has had a significantly higher investment into the research of precast and the shift towards its use

This could explain UK’s shift towards precast being a lot stronger than Australia’s

Brisbane is not yet in line with mega cities (Sydney and Melbourne) due to the lack of density and lack of importance on construction time according to Ramin Amini from Austral and their market research

In 2015, University of Melbourne awarded $4 million to establish the Australian Research Council (ARC) Training Centre for Advanced Manufacturing of Prefabricated Housing

The funding allowed 14 PhD and 6 post-doctoral positions for duration of four years

Moving Forward…

Changes to Current Research

Place more emphasis on commercial research instead of residential research

Evident a lot of research and conclusions had been drawn from residential research as there was not a great deal of research available on commercial particularly in Australia

Recommendations for Future Research

In depth study to be conducted over a longer period of time to allow ample opportunity to contact companies and gather data

Companies were quite time poor and hence were unable to answer questions to the depth that was required longer time could solve this

Sending the questions by email could potentially overcome lack of depth, however this results in more time required following up and hence a larger time frame would be required

Thankyou!