Influence of HPFRCC Compressive Strength and Confinement on Concrete

Abstract

The article analyses behavior of compressed concrete cylinders which were strengthened with external high performance fiber reinforced cementitious composite (HPFRCC) layer. Two different HPFRCC materials were used for the strengthening, which differed in fiber type. Two different types of loading were applied as well. The load was transferred through the whole cross section of the strengthened element and through the core – internal concrete. Loading through the whole cross section allows to validate the mixture law. Loading through the internal concrete allows to investigate the confinement effect. Comparison of theoretically calculated and experimental strength shows that mixture law and confinement effect is valid. Confinement by HPFRCC allowed to increase the strength of concrete about 4 times, but the ultimate strain remains similar. The strength of elements loaded through the whole surface has increased much more and additionally the ultimate strain has increased too.

Efecto Del Contenido Pasta Y Agregados Finos Sobre Las Propiedades Del Hormigón Drenante

“…(18-40) Si bien el hormigón drenante se considera una mezcla sin finos, un pequeño porcentaje de partículas finas puede incorporarse para incrementar la resistencia a compresión. La inclusión de agregados finos genera una capa de pasta y/o mortero alrededor de los agregados gruesos de mayor espesor generando un incremento de resistencia (Kumar et al, 2017). Existe una relación significativa entre la resistencia a compresión y la razón agregado fino/ agregado grueso, que cuando alcanza 8 % genera un mayor volumen de mortero e incrementa la resistencia con una leve reducción de la permeabilidad (Schaefer, 2005).…”

Influence of the Amount of Steel Fibers on Fracture Energy and Drying Shrinkage of HPFRCC

“…e related research results show that the addition of the steel fiber into the cement matrix can greatly improve the fracture toughness and fracture energy of concrete [12][13][14][15][16]. To further improve the compactness and mechanical properties of concrete, in addition to adding steel fibers, fine pozzolanic reaction additives such as fly ash and silica fumes are also added [17][18][19][20][21][22][23][24][25][26][27][28]. Due to the pozzolanic reaction and filling, the composite further achieves a more compact structure, which is called HPFRCC [29][30][31][32].…”