Bond Strength of Bamboo Reinforcement in Light Weight Concrete

Bamboo reinforced concrete as a building material is expected to be an alternative to steel reinforced concrete. Due to the fact that steel is not renewable and polluting steel mills are fairly high. The bond strength is a major concern for the natural fiber used as reinforcement in structural composites. This paper reports study on the bond strength of bamboo reinforcement in concrete, to determine the adhesion reinforcement in concrete often do by the pull-out test. The research objective was bond strength of lightweight concrete and bamboo reinforcement. The test used light weight concrete with foam additives klerak. Bamboo slats were coated with paint and sprinkled with sand. The results obtained showed that the bond strength bamboo 60% of the bond strength steel.

Numerical modeling of high velocity impact applied to reinforced concrete panel

A numerical simulation of a high-velocity impact of reinforced concrete structures is a complex problem for which robust numerical models are required to predict the behavior of the experimental tests.This paper presents the implementation of a numerical model to predict the impact behavior of a reinforced concrete panel penetrated by a rigid ogive-nosed steel projectile.The concrete panel has dimensions of 675 mm675 mm200 mm,and is meshed using 8-node hexahedron solid elements.The behavior of the concrete panel is modeled using a Johnson-Holmquist damage model incorporating both the damage and residual material strength.The steel projectile has a small mass and a length of 152 mm,and is modeled as a rigid element.Damage and pressure contours are applied,and the kinetic and internal energies of the concrete and projectile are evaluated.We also evaluate the velocity at different points of the steel projectile and the concrete panel under an impact velocity of 540 m/s.

Interaction between matrix crack and circular capsule under uniaxial tension in encapsulation-based self-healing concrete

This paper investigates the fracture process of a capsule when subjected to uniaxial tension in encapsulation-based self-healing concrete.A circular capsule embedded in the mortar matrix is considered along with different ratios of core-shell thickness.To represent potential cracks,zero thickness cohesive elements are pre-inserted throughout element boundaries.The effects of fracture strength around the interfacial transition zone of the capsule are analyzed.The crack nucleation,propagation,and fracture mode of capsule are also discussed.The numerical results indicate that increasing the strength of the interfacial transition zone around the capsule can increase the load-carrying capacity of self-healing concrete.Moreover,given a similar fracture strength around the interface of the capsule,the fracture probability of capsule in encapsulation-based self-healing concrete is strongly dependent on the core-shell thickness ratio..

Computational modeling of fracture in concrete: A review

This paper presents a review of fracture modeling of concrete.The complex material,such as concrete,has been widely used in construction industries and become trending issue in the last decades.Based on comprehensive literature review,there are two main approaches considered to-date of concrete fracture modeling,such as macroscopic and micromechanical models.The purpose of this review is to provide insight comparison from different techniques in modeling of fracture in concrete which are available.In the first section,an overview of fracture modeling in general is highlighted.Two different approaches both of macroscopic and micromechanical models will be reviewed.As heterogeneity of concrete material is major concern in micromechanical-based concrete modeling,one section will discuss this approach.Finally,the summary from all of reviewed techniques will be pointed out before the future perspective is given.

Ballistic behavior of plain and reinforced concrete slabs under high velocity impact

This work presents a numerical simulation of ballistic penetration and high velocity impact behavior of plain and reinforced concrete slabs.In this paper,we focus on the comparison of the performance of the plain and reinforced concrete slabs of unconfined compressive strength 41 MPa under ballistic impact.The concrete slab has dimensions of 675 mm x 675 mm x 200 mm,and is meshed with 8-node hexahedron solid elements in the impact and outer zones.The ogive-nosed projectile is considered as rigid element that has a mass of 0.386 kg and a length of 152 mm.The applied velocities vary between 540 and 731 m/s.6 mm of steel reinforcement bars were used in the reinforced concrete slabs.The constitutive material modeling of the concrete and steel reinforcement bars was performed using the Johnson-Holmquist-2 damage and the Johnson-Cook plasticity material models,respectively.The analysis was conducted using the commercial finite element package Abaqus/Explicit.Damage diameters and residual velocities obtained by the numerical model were compared with the experimental results and effect of steel reinforcement and projectile diameter were studies.The validation showed good agreement between the numerical and experimental results.The added steel reinforcements to the concrete samples were found efficient in terms of ballistic resistance comparing to the plain concrete sample.