Savings on Sample Projects

Quantities below are for a typical bay of 8m x 8m

S. No

Description

Unit

HOLLOW CORE SLAB

CORCON CORRUGATED SLAB

 

Quantity

Rate RM

Amount RM

Quantity

Rate RM

Amount RM

1

Reo Grade 30 in Beams

m3

2.85

169.3

482.51

2.85

179.3

511.01

2

Sawn Formwork to side & soffit of Beams

m2

13.87

21.1

292.66

13.87

21.1

292.66

3

Reo  in Primary Beams

kg

499

1.55

773.45

499

1.55

773.45

4

110mm Reinforced Grade 30 concrete** in slab

m3

0

0

0

10.36

179.3

1857.55

5

60mm concrete topping

m3

3.84

232.5

892.8

0

0

0

6

Sawn F/W to soffit of slab

m2

0

0

0

0

0

0

7

Corcon to soffit of slab

m2

0

0

0

59.2

35.7

2113.44

8

Hollow Core Slab

m2

64

67.5

4320

0

0

0

9

BRC Mesh in slab

m2

79.3

4.42

350.51

64

4.88

312.32

10

Reo in Rib Beams

kg

0

0

0

221.7

1.55

343.64

8

Shear key bars

m2

64

4

256

0

0

0

 

 

Total Direct Cost

 

 

 

7367.92

 

 

6204.06

 

 

Estimated Crane Cost

day

0.9

1150

1035

0.6

1150

690

 

 

Total Overall Cost

 

 

 

8402.92

 

 

6894.06

 

 

Materials

 

 

 

 

 

 

 

 

Total Concrete

m3

n/a

 

 

13.21

 

 

 

Total Reinforcement Bars

kg

n/a

 

 

720.7

 

 

 

Total BRC Mesh

m2

143.3

 

 

64

 

 

 

 

Savings using CORCON

RM

 

 

1508.86

 

 

 

 

% Savings using CORCON

 

 

 

17.96%*

 

 

 

19 SEPTEMBER 1995

Decoin Pty Ltd
27 Townsville St
FYSHWICK ACT 2609

Attention: Mr Andy Stodulka

RE: Flooring Systems

As requested we have undertaken a cost review of your product 'Corcon' flooring system and report as follows.

Concrete slab and beam system spanning 7.50m achieving a 1.5 hours fire resistance rating and a 4KPa loading was costed at a total of $67.00/m2

Concrete

$12.60

Reinforcement - bar

$3.90

Reinforcement - mesh

$5.50

Corcon formwork hire charge

$10.00

Formwork labour

$16.00

Surface treatments

$6.00

Propping etc

$4.00

This rate of $67.00/m2 compares with other forms of flooring system as follows

Timber flooring supported on250x50mm joists at 450mm centres with a 310UB40 beam at mid span

$82.00/m2

Concrete slab supported on 0.7mm Bondek with Universal beam at midspan

$72.00/m2

R....... flooring system including topping and joints

$98.00/m2

U..... ..... system, mesh reinforcement, concrete topping, supporting system and cranage

$86.00/m2

Transfloor system supporting system topping and reinforcement

$93.00/m2

All the above calculations are related to a 9x7 m standard panel. No allowance has been included for any non standard or irregular layouts etc.

Yours faithfully


P. W. Lonsdale

 

 

To Andy Stodulka

CORCON Forms

Dear Andy

Ref: Comparative savings

This is not to mention the pace of work schedule since it is a lot faster to work especially setting and stripping

Thanks and hope that this could be of help

 Summary of Cost and Material Saving for Corcon v.s. C-Joist*

 

COST

Corcon (Pesos)

C-Joist (Pesos)

Area
450 sq m

P 228,142.00

P 534,099.00

Cost
per sq m

P 507.00

P 1,187.00

Pesos Saving
per sq m

+P 680.00
(57%)

-

Weight Saving
per sq m

86 kg

-

Weight Saving
Column/Floor

3,200 kg

-

*Source: FORMAPLY Pty Ltd, Manilla, Philippines.

      THE IJM EXPERIENCE WITH CORCON IN MALAYSIA

IJM, a multinational vertically integrated construction company provides turnkey projects services through out the world. IJM has an annual turnover in excess of 1 billion RM. In 1998, Crendon Building Systems Sdn. Bhd.(CBS), the Industrialized Building Systems Division of IJM, introduced CORCON in Malaysia. Major factors influencing the decision to use CORCON were prospects of  high quality finishes  and speed of construction, even at comparable cost to alternate systems.

An initial area of 20m with a span of 6m was tested to a load of 500kg/m with no appreciable deflection or cracking.  This satisfactory performance, including ease of  installation, dismantling, quality and speed encouraged CBS to proceed with a 4000m multi-level carpark in Kuala Lumpur . This project was completed within 3 months using 500m of CORCON.  Simultaneously IJM commenced another multi-level car park for a Condominium where an area of 6000m was completed in 2 months using 1000m of CORCON formwork compared to three months scheduled for an alternate hollow core slab system.  Being in the critical path, the project was able to be completed 1 month earlier.

In addition to the reduced cost (See Table 2) and excellent performance, positive endorsement from Client/Architect/Consultant and Sub-contractor provided affirmation to IJM resulting in a decision to continue promoting the system.

Currently, IJM is considering CORCON for 3 levels of Car park in another housing project, as well as shopping malls, and commercial and industrial buildings.

 

 

      COMBINING TRADITION WITH COST SAVINGS

Cost is a key consideration in any project, with the best systems for the lowest price clearly offering the most favourable solution.

Pierre Dragh, Decoin P/L, Kieren Mudgway, TCM Meinhardt (Darwin), Phoon Wai Weng, IJM (Malaysia), Ashish Agarwal, IJM (Malaysia) and Frederick Erum, Formaply Industries P/L (Manila) give details of aninnovative formwork system which aims to fulfil all these requirements.

Winner of 11 major industrial awards, the innovative formwork system Corcon derives its name from the combination of CORrugation and CONcrete. The reusable lightweight sheet metal form system optimises the traditional rib slab construction by using corrugated arch metal sheets spanning over a series of beam moulds to form the suspended concrete slab. The corrugated arched metal sheet enables the rib beam spacing to be increased to 1200 mm from the conventional 600 mm, enabling the reduction of scaffolding support by 30%. Special features of Corcon contribute to enormous savings in construction cost and protection of scarce environmental resources. The integrally cast series of beams and intermediate arches reduce the concrete and steel reinforcement required in a conventional slab system by up to 30%. The fact that Corcon formwork is reusable adds to the cost effectiveness of the system.

Extensive acoustic and fire testing and several multi storey constructions in Asia and Australia have proven the viability of the Corcon system.

History

Patented throughout the world, Corcon formwork was developed by A.M. Stodlka in response to an increasing shortage of good quality plywood and the increasing need for safe, economical and durable housing in Asia.

The first Corcon slab was installed in a two storey residence in Queanbeyan, NSW in March 1995. Since then, over 80 000m2 has been placed including 10 000m2 installed in Kuala Lumpur.

Unbeknown to the inventor, Francois Hennebique has patented a slab and rib beam system a hundred years earlier which had fallen into disuse due to the high cost of timber and labour. The Corcon slab, in contrast, is both easier and less expensive to construct from both labour and material points of view.

Analysis

Contiguously cost rib slab systems give enhanced structural performance by making use of the high shear resistance of the slab and the high bending resistance of the ribs. The slab between the ribs is capable of supporting considerable dead loads without slab reinforcement, due to the natural arching effect. The arching itself contributes to the reduction in slab weight.

Rib beam depth governs the I value of the system. The higher the I value, the less the deflection.

The shear deflection and full scale destruction testing, carried out by Decoin Pty. Ltd. in Australia, has shown excellent results. Additional tests by CSIRO have established more than adequate fire and acoustic ratings.

A 5 x 4 m specimen Corcon slab with 85 mm minimum thickness and no top reinforcement supporting 5 kPa demonstrated the following test results and characteristics. [CSIRO Test FSH0684 - 12th July 1999]

In 1999, Decoin entered the Guinness Book of Records for casting a 14 m post-tensioned Corcon slab with as little as 140 mm average thickness and 3 kg of cable/m2. The slab carried a load of 300 kg/m2 with no deflection.

Benefits and savings

Easy logistics

Corcon is a fully interlocked formwork system. The compact stacking allows for ease of transportation, storage and on site handling. 500 m2 of forms weigh less than 13 t, and can easily be transported in an area covered by a 6 m container. Each Corcon element can be easily manhandled, eliminating the need for cranage.

Reduced material usage

The beam moulds replace the need for conventional bearers in a plywood system, and due to their self-supporting characteristics reduce scaffolding by 30%.

The tremendous reductions in concrete and reinforcement are achieved by the increased stiffness generated by the supporting beams and self-weight reduction of the arched corrugated intermediate joining slabs.

The resulting slab is much stronger and more earthquake resistant than any equivalent system. In addition, there is potential for much larger spans than achievable by any other design and hence fewer columns and/or conversely lesser foundation loading.

The most significant benefit, perhaps, is the reuse capability of the formwork. Throughout most of Asia, plywood is generally of poor quality and is best used a few times only. The Corcon sheet metal system could easily be reused more than 20 times (depending on the care taken). At the end of its reusable life, the elements are readily absorbed into a vigorous recycling system where the sheets can be reused as lost formwork, or incorporated into low cost construction.

Environment friendly

As highlighted above, the savings in the material usage generates less embodied energy and saves over 2 kg of CO2 gas emission/m2 of slab. Reduced logistic requirements will also lessen the environmental hazards.

The reusable features of formwork almost eliminates the use of natural timber and in turn will protect the forest reserves.

Cost savings

Studies undertaken by several consultants throughout Asia demonstrate considerable savings compared to the next lowest cost system. Formaply (Manila) compared the use of Corcon to a C joist system consisting of precast inverted T beams and a sprung reusable metal pan with a resulting 57% reduction in cost. In fact, Corcon has been selected to form a 250 000 m2 slab for 6000 units for the Payatas Housing Project in Quezon City, Philippines. The total project cost amounts to US$ 110 million, with F.Q. ESTEBAN and Associates acting as project consultants.

Similar studies have also shown enormous cost savings which vary according to the relative input costs, the largest savings in either areas of low wage structure, high cost of materials and cranes, or in areas of very high wage cost and high cost of raw materials.

*Source: Concrete Engineering International March/April 2000, P19-P20.

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