Good design can provide more efficient facilities and a better environment for both staff and students. Concrete construction presents great opportunities for the project team to meet the needs of the client by helping to improve the function, value and whole life performance of the facility. The use of concrete can satisfy the key design criteria for schools at no extra cost.
As well as providing the structural frame, concrete can be used to improve the overall performance of the building. The following list gives an indication of the many benefits of using concrete for an educational building.
Comfort is important for effective teaching and learning, creating a school building environment that contributes to lifting the spirits and raising aspirations. Utilising the inherent thermal mass of concrete enables cooling to be provided by the fabric of the school building and stops classrooms overheating.
Concrete is an inert material, with no harmful emissions to affect staff and pupils. Through its very nature, concrete provides robust surfaces for walls, partitions, columns, soffits and cladding that are easily sealed and free of ledges or joint details, which are difficult to clean. Aesthetics, ease of cleaning and a healthy atmosphere all lead to enhanced user satisfaction of concrete schools.
Good acoustics are essential for all learning activities and adequate sound insulation is particularly necessary for areas with a high emphasis on listening carefully, such as music. Concrete’s mass and damping qualities can easily meet the required Building Regulations acoustic performance BB93 (9) and this contributes to a productive environment, isolated from the noise and vibrations from adjoining rooms.
Concrete is a robust material that is capable of withstanding the harsh treatment that can occur in a school building with minimal or no damage. Reducing maintenance not only reduces costs and disruption but prevents the building from looking neglected which can lead to lack of respect for the facilities.
Flexibility and adaptability are key design requirements for any school. In the short term, flexibility is needed to rearrange the teaching environment to suit different activities. This may be as simple as moving furniture and equipment, but the size and shape of any room must suit a variety of layouts. In the longer term, adaptability is needed over the life of the school to allow internal walls to be moved, to change the size or use of spaces. Concrete frames can provide long spans with flat soffits which will facilitate the movement and location of demountable partitions and relocation of more permanent internal partitions.
Concrete is inherently fire resistant, and unlike some other materials, normally requires no added fire protection. Each year more than 2,000 schools in the UK suffer fires large enough to need action by local fire brigades. The odds that a school will experience such a fire in any one year are one in fifteen. The inherent fire resistance of concrete results in it often performing in excess of design requirements for occupant safety.
Concrete offers a whole range of options for meeting the requirements of a particular project. The options outlined below are the most popular for educational buildings. More information on concrete frame solutions can be found in concrete frames and the publication Economic Concrete Frame Elements.
Flat slab construction
Flat slabs are slabs supported on columns without any beams. To give maximum future adaptability many schools are currently being built using flat slab construction, typically creating buildings configured on grids of 7.2m to 8.4m.
A flat slab structure is the preferred construction choice for schools because of speed of construction, excellent sound and vibration performance, and the ability to best facilitate the installation of building services and partition walls.
Increasingly, buildings with flat slabs also include post-tensioning to either reduce slab thickness or provide longer spans. Post-tensioning a flat slab typically reduces the slab depth by 50mm. Post-tensioned flat slabs give the minimum floor-to-floor height of all construction forms in any material.
Hybrid concrete construction
Combining the best qualities of precast concrete (accuracy, high quality finishes, off-site manufacture) with those of in-situ construction (flexibility for late changes, mouldability, robustness, two-way spanning, local manufacture), hybrid concrete construction is increasingly popular with designers. There is a range of options available. For more information refer to The Concrete Centre publication Hybrid Concrete Construction.
Load-bearing wall construction
In-situ concrete walls, precast concrete walls, concrete twinwall and crosswall construction are all ideal structural options for classrooms. Walls can be located on facade and corridor lines, allowing flexibility in the length of classrooms. They are efficient as they are structural, both vertically and laterally, and architectural as partitions or the inner leaf of cladding.
An independent cost study for schools has been carried out by a team comprising Architecture plb, Arup, Davis Langdon and Costain. Six structural options were fully priced, with the costings based on detailed plans and structural solutions. The study found that a post-tensioned slab was the most economic solution and that as well as comparing the cost of the structural frame, the benefits discussed above should be including in the cost comparison because they can reduce costs for other elements of the building. For further information, see the Schools brochure, or the more detailed full Cost Model Study, both published by The Concrete Centre.