Energy dissipation capacity of fibre reinforced concrete under biaxial tension–compression load. Part I: Test equipment and work of fracture

Energy dissipation capacity of fibre reinforced concrete under biaxial tension–compression load. Part II: Determination of the fracture process zone with the acoustic emission technique

“…Fibres in concrete mainly increase the resistance to crack propagation of the material due to the friction caused by the fibre pull-out mechanism or by fibre breakage. These mechanisms are present in both uniaxial tension-and biaxial tensioncompression loading scenarios, however, as it was demonstrated in the accompanying Part I of this paper [1], the damage propagation and degree, and as a consequence the energy dissipation capacity of the material significantly changes. The energy dissipation capacity is significantly lower in the biaxial load case than in the uniaxial load case.…”

An analytical solution for evaluating the effect of steel bars in cracked concrete

“…Regarding the large-deformation behavior of reinforced concrete specimens, Su et al [11] concluded that a significant improvement of the flexural strength of a reinforced concrete beam results from the compressive arch action, which could be influenced by the flexural reinforcement ratio and span-height ratio of the beam. In addition, an interesting phenomenon was observed by Tschegg et al [4], who investigated the differences in dissipated energy under biaxial tension-compression and uniaxial tension load of reinforced concretes using the wedge splitting test. Their results showed that the specific fracture energy for a biaxial tension-compression load is on average 20-30% lower compared to that of a uniaxial tension load, which is attributed to the damage mechanism of the concrete matrix and deterioration of the aggregate-cement-paste interfaces in case the section is additionally loaded with compression stresses.…”

A gênese e o desenvolvimento do programa de extensão - AFRID - da Faculdade de Educação Física da Universidade Federal de Uberlândia: de 1989 a 2014

“…A forma geométrica das amostras está ilustrada na Figura 47 (TSCHEGG et al, 2015). O método de ensaio de abertura por encunhamento para carga uniaxial é caracterizado por inicialmente posicionar a amostra em um suporte linear estreito.…”

“…A força (F M ) aplicada pela máquina de teste é transmitida por meio das peças de transmissão para a amostra. Dessa forma, ocorre a abertura da amostra por encunhamento, conforme apresentado na Figura 48 (TSCHEGG et al, 2015).…”

“…Os valores obtidos de F H e F V dependem do ângulo da cunha, sendo que quando este ângulo é inferior a 15º não há interferências mensuráveis nessas forças (TSCHEGG; ELSER; STANZL-TSCHEGG, 1995a). A velocidade de deslocamento da máquina de teste deve ser mantida constante em 0,5 mm/min (TSCHEGG et al, 2015). O erro de medição devido ao atrito entre as peças de transmissão e a cunha é minimizado pelos rolamentos que compõem o equipamento de ensaio e, por isso, é insignificante (menor que 1%).…”