Volume 3 Issue 1
Authors: Jeffery S. Volz; Mahdi Arezoumandi; Jonathan Drury
Abstract: This study presents the results of an experimental investigation that evaluates the effect of recycled concrete aggregate replacement level on the fracture energy of concrete. This study includes five mixes with 0, 30, 50, 70, and 100% recycled concrete aggregate as a coarse aggregate replacement. This experimental program consisted of 20 fracture beams to study the fracture behavior of concrete. The experimental fracture energies were compared with the fracture energy provisions of different design codes and also different analytical equations. Furthermore, statistical data analyses (both parametric and non-parametric) were performed to evaluate whether or not there is any statistically significant difference between the experimental fracture energies of different mixes. Results of these statistical tests show that the mix with higher level of recycled concrete aggregate replacement level has lower fracture energy.
Keywords: Fracture Energy; Recycled Concrete Aggregate; Virgin Concrete Aggregate
Size Dependent Shear Strength Of Reinforced Concrete Deep Beams Based On Refined Strut-And-Tie Model
Authors: R. Sundaresan; G. Appa Rao
Abstract: This paper reports on analytical investigations on the development of shear strength expression applicable to reinforced concrete (RC) deep beams. The shear strength of RC deep beams provided with shear reinforcement incorporating size dependent parameters has been studied. The development of the shear strength expression is based on the shear transfer mechanism of deep beams idealized through a refined strut-and-tie model according to the modified Bazant’s size effect law and a large experimental data. The accuracy of the proposed expression has been validated with other existing models including the ACI Strut-and-Tie model. By incorporating various influencing parameters such as compressive strength of concrete, shear span-to-depth ratio, effective depth of beam and percentage of flexural steel reinforcement, the estimation of the shear strength of RC deep beams has been observed to be relatively better.
Keywords: Deep Beam; Shear Strength; Strut-and-tie Mode; Size Effect; Reinforced concrete