A lack of knowledge, specifically among structural engineers on specifications for concrete floors, poses a challenge to the industry, says concrete technical services provider The Concrete Institute (TCI) MD Bryan Perrie.
“Concrete floors are effectively concrete pavements and should be designed, detailed and constructed as such by pavement engineers.”
Using structural concepts, such as reinforcement, to increase load-carrying capacity and reinforcement through construction joints results in unacceptable cracking and, in some cases, overstressing of the floor and structural failure, Perrie explains.
He adds that there is often a lack of understanding of restrained drying shrinkage in floors. Engineers are often not aware that there are design guides and software available for the design of concrete floors that would prevent the floor from cracking.
Perrie attributes this lack of knowledge and understanding to an engineer not grasping the requirements of the client and not being able to design and specify accordingly. In some instances, main contractors might not have a clear grasp about the risks for subcontractors when working under certain conditions.
To mitigate this challenge, TCI runs a one- day Design and Construction of Industrial Floors course that is aimed both at engineers who have past experience or training in concrete technology, but would like to refresh their knowledge on important concrete concepts, and younger engineers wanting to learn about concrete floors. The syllabus covers design, joints reinforcement and surface finishing. It also covers training on construction, which covers the selection of materials, as well as construction of the subgrades and subbase, concrete requirements and the finishing of concrete industrial floors.
The institute facilitates seminars and workshops – in conjunction with The Concrete Society of South Africa – to keep contractors informed about the issues and changes in the way floors are built.
Perrie believes that these workshops and seminars are necessary, as there have been many changes in the way floors are designed and built.
Although a concrete floor is constructed on the ground with minimal reinforcement, it still has to have the correct thickness and a hard-wearing, dust-free surface; be level, flat and at the correct height; and has to carry large loads over its entire surface, including across joints, corners and edges.
“It must also be aesthetically pleasing with minimal surface defects and cracking. Concrete used for the floor needs plastic and hardened properties and, so, the mix designs for these concretes are more constrained and require greater attention to detail,” adds Perrie.
Moreover, TCI offers 16 different courses – varying from one day to five days – that are developed to meet the requirements of those working in the concrete and concrete-related industries.