The industrial concrete floor is a very important part of an industrial building, distribution center, storage or shopping mall, and it must have high quality surfaces for operation. To achieve the high quality we must know the problems and how to treat them. The most important problems on the concrete floors are: (i) cracks which are caused by shrinkage and creep, (ii) curling resulting in a loss of contact between concrete slab and sub-base, and (iii) unevenness In this thesis, it is aimed to investigate the effect of optimizing the concrete mix with and without additional shrinkage reducing agents (SRA) to reduce the crack risk in industrial concrete floors. Four types of concrete recipes are used (A-D) which include a recipe with optimized mix design for minimum shrinkage, a reference recipe (standard mix), an optimized mix with SRA and a fourth recipe with the reference plus SRA. The testing program extended to 224 days of age and comprised e.g. free-shrinkage, restrained shrinkage, weight change, modulus of elasticity, compressive strength, splitting tensile strength and creep of concrete. At early ages, a 28 days, there are large differences in shrinkage-time relations for different mixes. Later than 28 days, the relations are closer. A comparison among shrinkage and creep test results of four recipes shows that recipes A and C have greater crack risk than recipes B and D. The recipe D has also the best result in restrained shrinkage test. These results are because of the aggrega-te graduation, type of cement and shrinkage reducing agents which all have a direct influence on the concrete properties. These tests were done by CBI (The Swedish Cement and Concrete Research Institute) during 2009.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Os pisos industriais devem atender aos critérios de segurança, funcionalidade e durabilidade das estruturas de concreto. A fim de analisar o desempenho de placas de concreto apoiadas sobre base elástica quando submetidas a ações diretas e indiretas, foram elaborados diversos modelos analíticos e empíricos. Com o avanço tecnológico e o advento de softwares desenvolvidos através de processos numéricos como o método dos elementos finitos (MEF), a aplicação desses modelos foi facilitada. Este trabalho aborda os métodos de cálculo existentes e utilizados na execução dos projetos estruturais de pisos industriais de concreto. / The industrial floors must meet the criteria of security, functionality and durability of concrete structures. In order to analyze the performance of concrete slabs supported on elastic foundation when subjected to direct and indirect actions, were developed several analytical and empirical models. With advances in technology and the advent of software developed by numerical processes such as finite element method, the application of these models was facilitated. This paper presents the calculation methods used in the implementation of structural designs of concrete industrial floors.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Os pisos industriais devem atender aos critérios de segurança, funcionalidade e durabilidade das estruturas de concreto. A fim de analisar o desempenho de placas de concreto apoiadas sobre base elástica quando submetidas a ações diretas e indiretas, foram elaborados diversos modelos analíticos e empíricos. Com o avanço tecnológico e o advento de softwares desenvolvidos através de processos numéricos como o método dos elementos finitos (MEF), a aplicação desses modelos foi facilitada. Este trabalho aborda os métodos de cálculo existentes e utilizados na execução dos projetos estruturais de pisos industriais de concreto. / The industrial floors must meet the criteria of security, functionality and durability of concrete structures. In order to analyze the performance of concrete slabs supported on elastic foundation when subjected to direct and indirect actions, were developed several analytical and empirical models. With advances in technology and the advent of software developed by numerical processes such as finite element method, the application of these models was facilitated. This paper presents the calculation methods used in the implementation of structural designs of concrete industrial floors.