Commercial buildings benefit from improved green credentials, rapid installation of a high quality product and a very wide range of potential design options.
The benefits of precast flooring in commercial buildings include:
Case study example: PCE Ltd - Volkswagen Car Showroom, Service Centre, MSCP, London.
PCE has delivered a multi-functional building for Volkswagen over 5 floors, offering areas for a showroom, service centre, offices and car parking (7300m2) to a busy congested London site. They worked with main contractor Longcross to win the project with an alternative tender by proposing a precast solution. This solution utilised innovative GT slabs, box units for stair/lift cores, removed a central row of columns, reduced lorry loads, reduced operatives on site, incorporated architectural circular white columns and delivered the project earlier. Furthermore, 3-D modelling during design and tight production control avoided clashes and erection delays.
The project is a credit to PCE and their precast manufacturer suppliers, British Precast members: FP McCann, Evans Concrete, Banagher Precast and Ebor Concrete.
Concrete’s inherent properties are ideally suited to the education sector - its reputation for durability offers important savings in repair and maintenance within the school environment. Furthermore, whole of life savings can be attributed to concrete’s thermal mass which is acknowledged to be a valuable solution to the problem of overheating and its associated cooling costs.
Precast concrete manufacturers can supply a wide variety of external finishes, whilst details such as solid floors and insulated walls deliver concrete’s acoustic benefits and contribute to a building’s fire safety. There are many reasons to use offsite build systems, including:
The University Of Northampton’s new Waterside development will cater for 14,000 students and 2,000 staff. The 58-acre campus includes five low carbon buildings for teaching, leisure and student accommodation and is scheduled to open in September 2018.
Precast Flooring Federation member, FP McCann, played a significant role in the construction of the Senate Building, which was the first new building to be ‘topped out’ as part of the £330 million scheme. FP McCann secured the contract to supply and install hollowcore flooring and lift shaft lids to the Senate Building as part of the main structural steel build led by Shipley Structures. The design and build hollowcore package was undertaken by FP McCann’s in-house design team based. Hollowcore floor spans ranging from 1.0 m to 7.25 m and totalling 3,800 m² were installed on the four-storey building over a three-month period, as phased in by Shipley Structures.
The hollowcore system is 200 mm deep, has a fire rating of one hour and, as part of the overall elements contained within each floor, the thermal resistance of the hollowcore units is 0.167 m2 K/W.
As part of the contract, FP McCann also completed all the wet work requirements and employed a specialist team from Beresfords Flooring to install ties at/over supports in order to protect the building against disproportionate collapse in accordance with the Building Regulations.
Commenting on the supply and fix contract, Chris Murphy Contracts Director of Shipley Structures said, “The hollowcore panels and lift shaft lids were supplied and fitted to the design specification and to the highest standard. With little extra preparation, the finishing contractors were able to apply paint and vinyl surfaces to the flooring surfaces.”
The new world-class University Of Roehampton Library is a 70,000 square foot, five-storey building, housing 350,000 books and 1,060 study spaces. The £34 million building was manufactured offsite by Precast Flooring Federation member, Creagh Concrete.
Creagh Concrete was responsible for the design, manufacture, delivery and installation of all members of the precast architecturally exposed concrete frame with single and double height columns, plate flooring, precast beams and precast stairs. The facade is a lightweight steel frame system with weatherproof boarding and an outer precast brick-clad skin.
A precast concrete frame and hybrid precast/insitu concrete Omnia flooring slabs were used to create the frame for the new library. Installation time was an hour to erect a column and half-an-hour for each slab.
The floor slab construction has integrated M&E, including heating and cooling pipework. The embedded pipework allows the entire exposed soffit of the concrete flooring to be used as the heating or cooling medium, using minimum energy and providing maximum comfort to the large library building. Due to the low operating temperatures, the system lends itself particularly well to be combined with heat pumps, ground heat exchangers, solar energy and other alternative energy sources. The system maintains the concrete surface temperature close to the room air temperature, resulting in a high degree of self-regulation from the system.
The precast floor units were manufactured on steel tables ensuring a very high standard of finish. The product is therefore suitable for applications where the soffit of the concrete slab is left exposed in the final case, such as this.
Busy construction sites can be noisy so building a new library within a few metres of sleeping students and exam theatres was a tricky task. Since there was limited room to make deliveries and the build system requires the constant ‘feeding’ of precast components, the task of organising the project necessitated close liaison with the university.
It is speed of construction that underlines the attractiveness of using precast concrete components. The amount of repetition suited the process, the project and the site. The two stair cores were erected in five weeks and the frame, including the precast flooring, took thirteen weeks to install. The fast track advantages of the offsite build system and precast components met the needs of this time-sensitive education scheme, ensuring that the library opened its doors on time for the new academic year.
Masonry offers high quality facing materials that are cost effective for large projects but also down to the smallest scale. It can also provide structural elements: vertical load bearing and stability walls as part of the building enclosure or as internal partitions, providing fire enclosure, additional security and acoustic separation. It’s robustness and durability means it is particularly useful for reducing maintenance in areas likely to suffer high wear and tear.
Masonry can provide the building envelope which together with internal walls or columns can be designed to provide structural requirements of vertical load bearing and stability for low rise buildings (typically up to 4 storeys) . For taller buildings it can also form the building envelope, but tends not to be part of the vertical load bearing structure but rather as facing or infill. Taller buildings can be constructed from masonry cross wall construction, but this is far less common nowadays.
MPA Masonry is part of the Mineral Products Association, the trade association for the aggregates, asphalt, cement, concrete, dimension stone, lime, mortar and industrial sand industries. www.mineralproducts.org
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