Título:	Comportamento ao puncionamento de lajes cogumelo de concreto armado com pilares retangulares e furos de grandes dimensões
Autor(es):	Borges, Liana de Lucca Jardim
Orientador(es):	Melo, Guilherme Sales Soares de Azevedo Gomes, Ronaldo Barros
Assunto:	Lajes cogumelo Pilar retangular Lajes - concreto armado
Data de publicação:	16-Abr-2020
Data de defesa:	12-Fev-2004
Referência:	BORGES, Liana de Lucca Jardim. Comportamento ao puncionamento de lajes cogumelo de concreto armado com pilares retangulares e furos de grandes dimensões. 2004. xxv, 367 f., il. Tese (Doutorado em Estruturas)—Universidade de Brasília, Brasília, 2004.
Abstract:	Twenty reinforced concrete flat slabs (3000 mm x 3000 mm x 200 mm) with concrete resistance around 40 MPa and effective height between 139 and 164 mm are tested, submitted the symmetrical punching. The principal variables of the research were: relationship between the dimensions of the rectangular dimension of the column (Cmáx/cmin between 1 and 4); the number of holes at the columns region; and the shear reinforcement detailing. A proposal for inclusion of the parameter Cmáxd (Cmax being the largest dimension of the column and d the effective height of the slab) in the expressions of the punching shear resistance of CEB-FIP (1991) and ACI (2002) is presented. For the code NBR-6118 (2003) it is suggested a way to calculate the effective control perimeter of flat slabs with holes close to the column. The results showed a reduction in the growth rate of the punching shear resistance of the slabs when the relation Cmax Cmin is increased, maintaining Cmin (smaller dimension of the column) constant, with the shear forces concentrating on the extremities of the column, mainly with the increase of the relation Cmax Cmin. With relation to the presence of holes adjacent to the column it was observed a reduction in rigidity and in resistance up to 23% for the dimensions of holes used. The use of shear reinforcement, as disposed in the research, reestablished and even overcame the punching shear resistance of the monolithic reference slab. The design codes that for the calculation of punching shear resistance considers the column geometry (ACI (2002), EC-2 (1992)), and considers holes close or adjacent to the column (ACI (2002), BS8110 (1997), EC,-2 (1992), EC-2 (2001) and NBR-6118 (2003)), were conservatives (Vsg/Vcaic between 1,21 and 1,50) in estimating the rupture loads of the slabs with rectangular columns without holes nor shear reinforcement (series 1). CEB-FIP (1991) and NBR-6118 (2003) presented estimates practically equal to the experimentally obtained (VExp Vcaic = 0,99) for these slabs. The proposal of the inclusion of the Cmax d parameter for the calculation of the punching shear resistance in the expressions of ACI (2002) and CEB-FIP (1991) led to closer estimates for the slabs with rectangular columns and holes (series 2) and for the slabs with rectangular columns, holes and shear reinforcement (series 3). The proposal of effective control pcrimetcr calculation for the NBR-6118 (2003) code, using the B S8110 handbook method (1987) also led to closer estimates for the slabs with rectangular columns and holes (series 2) and for the slabs with rectangular columns, holes and shear reinforcement (series 3).
Unidade Acadêmica:	Faculdade de Tecnologia (FT) Departamento de Engenharia Civil e Ambiental (FT ENC)
Informações adicionais:	Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2004.
Programa de pós-graduação:	Programa de Pós-Graduação em Estruturas e Construção Civil
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

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