In February 2005, the Department of Education and Skills awarded ABM Design and Build the contract to design and construct a new 24 classroom school to serve as St. Patrick’s National School in Diswellstown, Dublin 15.
- This project consisted of the traditional build of a new national school which comprised three individual blocks linked by two glazed corridors. Two of the blocks were three-storey buildings which housed classrooms, ancillary plant and equipment rooms to form a teaching area of 24 no. classrooms. The third block was two stories tall and housed the administration for the school and a new general purpose hall/gymnasium.
- The design team were novated to ABM by the Department of Education.
- ABM reviewed the design and modified it to facilitate a faster program with less risk to the client. The traditional 6,000 sq. m of structural block work was replaced with pre-cast concrete walls which were erected in approximately 10 weeks. The project was complete before the programmed completion date and on budget.
- Diswellstown’s modular design lent itself to a precast system solution. The precast concrete system was chosen over traditional methods to reduce the construction programme and on-site labour. This system reduced the need for approximately 6,000 sq. m of block and plaster work and ancillary labour.
- The new system programme proposals were of advantage to the client mainly due to speed of construction.
The advantages of using precast concrete walls on this project were:
- The strength of precast concrete gradually increases over time. Other materials can deteriorate, experience creep and stress relaxation, lose strength and/or deflect over time. Studies have shown that precast concrete products can provide a service life in excess of 100 years.
- Precast concrete walls are non-combustible. Also, concrete does not lose its structural capacity as quickly as steel.
- Precast concrete increases schedule efficiency as weather will not delay production. In addition, weather conditions on-site do not significantly affect the schedule. This is because it requires less time to install precast compared with other construction methods, such as cast-in-situ concrete.
- It is evident from the successful completion of the school that any size of project can be accommodated using a precast solution, hence ABM’s decision to use similar systems on future projects. Additionally, because precast systems are designed and manufactured for simple connection, many of the components could be installed within a short time-frame. Once the windows and roof systems were complete, the building was ‘watertight’ allowing internal finishes to commence.