1969: founded by Wong Swee Chun
1982: first public housing construction project
2014: awarded contract for construction of an ICPH
2017: fully-automated Greyform factory opened
The Works: Facts & Figures
Operator: Greyform Pte Ltd
Location: Kaki Bukit, Singapore
Total surface area: 20,000 m2
Built area: 32,000 m2
Floors of dormitory block: 12
Works levels: 4
Off-premises storage levels: 7
Products: wall elements, floor elements (loosely reinforced and pre-stressed) hollow core slabs, made-to-measure mesh, staircases, 3D modules for bathrooms and kitchens
Production volume: 80,550 m3/year
Employees: 60 (production)
Straits Construction Group, one of the largest construction companies in Singapore, recently commissioned a plant for producing not just walls and floor panels, but also pre-stressed solid slabs and 3D kitchen and bathroom modules. The associated plant and software solutions have been developed by companies in the PROGRESS GROUP, while subsidiary EBAWE Anlagentechnik assumed the principal responsibility for the overall concept and installation.
For some years now, Singapore has been promoting industrialisation and automation of its construction industry by means of numerous guidelines and incentives. The state's objective is to optimise land use, improve productivity and quality, and create highly skilled jobs. In line with the slogan: out with time-consuming and labour-intensive traditional construction methods, and in with maximum pre-fabrication, highly automated factories producing precast concrete elements are being set up to increase usage of precast concrete in Singapore’s construction industry. In this context, precast concrete element technology takes on greater significance.
From left: Ryan Lim (Assistant General Manager, Greyform Pte Ltd), Hugh Lim, (BCA CEO, Singapore Government), His Excellency Dr Ulrich A. Sante (Ambassador of the Federal Republic of Germany to Singapore), Wong Chee Herng (Group MD & CEO, Straits Construction Group), Heng Swee Keat (Minister for Finance, Singapore Government), Wong Swee Chun (Chairman, Straits Construction Group), Lee Fook Sun, (BCA Chairman, Singapore Government), Sim Ann (Senior Minister of State, Ministry of Culture, Community and Youth & Ministry of Trade and Industry, Singapore Government), Kenneth Loo (Executive Director, COO, Straits Construction Group), Koh Yeong Kheng (Director for Finance, Straits Construction Group).
Precast concrete element technology for building space and rejuvenation of the city
Singapore’s Building and Construction Authority (BCA) is encouraging construction companies to invest in this forward-looking technology. Through tendering processes, it is making land available for production plants and is inviting tenders for projects, which are then realised by private firms. These factories that come under ICPH (Integrated Construction and Prefabrication Hub), will help create new buildings in a fast, cost-efficient manner, and thereby, rejuvenate the state’s building infrastructure for the coming years.
A second ICPH opened
On 3rd October 2017, the second ICPH was inaugurated. Constructed by Straits Construction Group in close cooperation with companies in the PROGRESS GROUP, the highly automated plant on 5 levels ensures the company's in-house supplies in prefabricated concrete walls and ceilings and entire room modules.
On 20.000 m2 building land Straits Construction has constructed a 12-storey dormitory block (in front) and a precast concrete element factory on four levels with attached high-bay warehouse. Figure: Greyform Pte Ltd.
Minister for Finance: "ICPHs important for Singapore"
At the plant’s opening ceremony in the presence of Singapore’s Minister for Finance, Heng Swee Keat, the Ambassador of the Federal Republic of Germany in Singapore, Ulrich A. Sante and the entire top management team from Straits Construction Group, it was unanimously felt that this technology has a secure future. In his speech, the Finance Minister stressed the importance of such highly automated plants. "ICPHs are significant developments, housing exciting innovations and technologies that can raise productivity and bring new energy to the building industry."
The highly automated carrousel plant (with shuttering and de-shuttering robot) allows Greyform with only a small workforce to meet precise delivery periods and the highest quality requirements.
ICPHs are based on four crucial points: firstly, they will optimise land usage, since several construction processes would be amalgamated in one place. Secondly, such plants increase labour productivity, since less time and a smaller workforce are required to produce precast concrete elements. Thirdly, the controlled production conditions improve the quality of prefabricated elements; and finally, new, more highly skilled jobs would be created, which would meet the increasing demand of the people.
Production on 4 levels
In September 2014, after Straits Construction Group was awarded the tender for the 20,000 m2 of building land in Kaki Bukit, the work for the new ICPH began. It comprises a four-storey factory and a 12-floor dormitory block. In conjunction, Straits Construction Group has founded its own subsidiary company Greyform Pte Ltd, to operate the works.
The factory building with its attached high-bay warehouse for floor and wall panels is unique in concept and form. On the ground floor the carrousel plant has been installed by EBAWE Anlagentechnik and lines for the production of pre-stressed elements have been installed by Echo Precast Engineering. The first floor houses the entire system from Progress Maschinen & Automation for the manufacture of made to measure mesh, while on the second floor the Tecnocom shuttering moulds for stationary manufacture have been housed. Bathroom and kitchen modules are finished on the third floor; these are then stored on the fourth and last floor.
Ground floor: highly automated carrousel plant
The highly automated carrousel plant occupies the greater part of the ground floor of the factory. Ryan Lim, Greyform's Assistant General Manager stated, "This plant is the first in Singapore to use automated robot technology. Its flexible design not only ensures the highest efficiency, but also guarantees that delivery times are rigorously adhered to - even where the elements are totally different."
A total of 48 pallets circulate on the circuit. At the start of every production cycle, they are loaded with the appropriate shutters by the Form Master shuttering and de-shuttering robot. Once the made-to-measure mesh has been inserted, the fresh concrete is accurately spread by an automatic concrete spreader and compacted. A levelling and vibrating beam ensures that the elements' surface quality is optimal. Finally, a pallet stacker places the precast concrete elements in one of a total of 38 shelf compartments for curing. When the finished wall and floor panels have been removed and transported to the high-bay warehouse, the shutters are removed, cleaned and automatically replaced in storage by the de-shuttering robot. Once the pallets have been cleaned, the cycle begins afresh.
Automatic delivery of the fresh concrete
Even the fresh concrete is delivered automatically to the carrousel plant. A bucket conveyor transports the material directly to the concrete spreader from a ground-batching plant, supplied by Wiggert & Co. GmbH. A second bucket conveyor system ensures that slipformer production is supplied with drier concrete.
Innovative high-bay warehouse for 5,800°t precast concrete elements
The plant's special feature is the high-bay warehouse. Because of the scarcity of space in Singapore, the warehouse has not been planned horizontally, as is usual, but vertically. It is fully automatic and in 3 towers on 7 different levels it offers space for a total of 5,800°t of sold walls and floors, pre-stressed elements and hollow core slabs. In addition, entire racks, rather than individual concrete elements, are stored and retrieved. This massively reduces standby time for the HGVs and therefore delivery time.
This degree of automation has a major impact on the productivity of the plant. "Within 10 days, a workforce of 60 persons is able to produce precast concrete elements for 48 four-room dwellings. On traditional construction sites, three to four times the number of employees and twice as much time would be required," says Ryan Lim with satisfaction.
Slipformer for the manufacture of hollow core slabs and pre-stressed elements
Greyform uses the S-Liner T40 slipformer from Echo Precast Engineering for the production of pre-stressed precast concrete elements. By means of three different slipformer moulds, not only is it possible to produce hollow core slabs 7-40 cm in height and 120 cm or 240 cm in width on the 84 cm long production lines, but also pre-stressed solid slabs 7-20 cm in height and 100 cm or 210 cm in width can be produced. Additional equipment, such as two different saws, a multi-functional trolley and the associated lifting equipment, complete the plant. "The hollow core slabs allow us to cover longer span with single elements – in addition, it is possible to work on the construction site with less columns," explains Ryan Lim.
First floor: Production of made-to-measure mesh
The steel mesh for all the production lines is produced on the first floor. "Here we have installed four different systems from Progress Maschinen & Automation, with which we are able to manufacture all the products required," says Lim. "This set-up allows us to react with a high degree of flexibility and to produce more than 100°t bespoke mesh, cages, bars and stirrups per day."
An M-System Evolution mesh welding plant is used here for the manufacture of bespoke mesh in various moulds and with bending run-off. The machine has been developed for flexibility in use and therefore blends in perfectly with Greyform's production concept. When the mesh has been produced, a crane automatically stores it in a buffer, from where the pallet circuit is supplied. Cage production is delivered, and pre-stressed ceilings are manufactured by manual processes.
Bars, bars with bending run-off, stirrups and 3D stirrups are manufactured by the second system, an EBA S16 Plus 3D automatic stirrup bender. Fast, automatic wire change and fully automatic setting of the straightening rate ensure that production is fast and continuous. In addition, a Shear Line bending machine for individual rebar and a cage welding machine have been installed.
Second floor: Staircase and 3D shuttering moulds
The second floor has been reserved for stationary production. In addition to the three staircase shutters and in cooperation with the Northern Italian prefabricated bathroom specialist Bathsystem S.p.A, four 3D shuttering moulds and the associated four production tables for the manufacture of bathrooms and kitchens have been delivered to Greyform. The 2.8 m high shuttering moulds are remarkably flexible, since both the wall shuttering and the floor slab are adjustable. This means that 3D elements can be produced in a variety of dimensions. Each module is manufactured in two sections, then placed together on one of the production tables, and provided with a floor.
Reduced costs due to pre-fabricated bathroom and kitchen modules
Because the pre-fabricated bathrooms and kitchens are up to 90% pre-fabricated, it is possible to reduce costs significantly. Sanitary equipment, electricity systems and furnishings are installed as part of the production process at Greyform. Thereafter, the elements are loaded onto HGVs and delivered just in time to the construction site, where a crane places them in their final position. The company is thus able to comply with the 65% quota for pre-fabricated bathroom modules imposed by the BCA.
Industry-specific MES and ERP systems improve productivity and quality
The software plays a large part in ensuring that the production processes run smoothly. The ebos® and ProFit MES systems, developed by Progress Software Development, consistently accompany all the aspects of the production process in the pallet circuit and manufacture of made-to-measure mesh. These integral systems thus replace a multitude of partial software solutions. This avoids interface problems and the employees can perform their entire work process in one homogeneous, user-friendly system.
erpbos®, a solution developed specifically for the precast concrete industry, has been installed as the superordinate ERP system. It serves the planning and control of all business and production processes - starting from sales, calculation, project management through production and installation planning to logistics, materials management, controlling and human resources. Says Ryan Lim about the Progress complete software package: "All these systems ensure a seamless flow of data, which increases not only our productivity, but also the quality and precision of our products."
Greyform: Focus on automation to secure the future
The overall concept of the system is in perfect harmony with Greyform's objectives. Lim sums up, "We are concentrating completely on digital technologies and automation to secure our ability to compete in the long term. We want to bring new, young skills into this old industry, and make it fit for the future."