scholarly journals Flexural Behaviour and Internal Forces Redistribution in LWAC Double-Span Beams

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5614
Author(s):  
Ewelina Kołodziejczyk ◽  
Tomasz Waśniewski
Keyword(s):  
Research Study ◽  
Rectangular Cross Section ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Normal Concrete ◽  
Aggregate Concrete ◽  
Moment Redistribution ◽  
Continuous Beams ◽  
Internal Forces ◽  
Reinforcement Interaction

This research study aimed to investigate the effect of the lightweight aggregate concrete and steel reinforcement interaction on the behaviour of continuous beams compared to the normal concrete of the same strength. This paper presents six full-scale, double-span beams with a rectangular cross-section made of both lightweight and normal concrete. The study confirmed that beams made of lightweight aggregate concrete achieve comparable flexural capacities to those made of NWC but their deformability and ductility are lower. Although the redistribution of internal forces depends mainly on the longitudinal reinforcement ratio, the influence of ultimate compressive strains of concrete is also noticeable. The ultimate compressive strains in LWAC are generally lower than in NWC. The lower rotational capacity of LWAC results in smaller degrees of moment redistribution in beams made of this concrete compared to normal concrete beams.

scholarly journals Ductility and internal forces redistribution in lightweight aggregate concrete beams

2020 ◽  
Vol 19 (4) ◽  
pp. 095-108
Author(s):  
Tomasz Waśniewski ◽  
Ewelina Kołodziejczyk
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Lightweight Concrete ◽  
Concrete Strength ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Brittle Behavior ◽  
Structural Applications ◽  
Internal Forces

Lightweight Aggregate Concrete (LWAC) is typically defined as concrete having a density smaller than or equal to 2200kg/m3 and can be obtained by mixing natural or artificial lightweight aggregates. There is a general scepticism regarding the use of lightweight aggregate concrete (LWAC) for structural applications. This concern is attached to the more brittle material behaviour which leads to lower ductility. This article presents a numerical parametric analysis of the behaviour of the reinforced LWAC cross-sections under the immediate load taking into account the density of the LWAC concrete, concrete strength and tensile reinforcement ratio. Numerical analysis of  the beams was conducted in OpenSees, an open–source nonlinear finite element method framework. One-dimensional elements, with three degrees of freedom at each end, were used. Bending stiffness in the integration points was calculated based on the sectional moment – curvature relationship. The analysis showed that there is a relationship between the ductility of the cross-sections made of lightweight concrete and its density class. It is associated with limited compressive strains and the brittle behavior of LWAC. The limited rotation capacity of the reinforced concrete sections made of LWAC also affects the ability of redistribution of internal forces in statically indeterminate beams

Mix Proportion Design and Basic Mechanical Properties Experiment of Self-Compacting Lightweight Concrete

2012 ◽  
Vol 450-451 ◽  
pp. 329-333
Author(s):  
Xi Jun Liu ◽  
Yu Mei Wang
Keyword(s):  
Mechanical Properties ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Compression Tests ◽  
Normal Concrete ◽  
Aggregate Concrete ◽  
Mix Proportion ◽  
Sand And Gravel ◽  
Volume Method

In order to get the requirements of workability and basic mechanical properties of self-compacting lightweight aggregate concrete, fixed sand and gravel volume method and overall calculation method are used to mix design. Slump flow and L-box tests are used to test the workability of self-compacting lightweight aggregate concrete, the strength increasing and the final value are tested by compression tests. For contrast, a set of common concrete is selected to compare the differences of efficiency. Tests indicated that the 5 groups of self-compacting lightweight aggregate concrete can get the requirements of workability and compressive strength, and the structure efficiency can be significantly higher than normal concrete.

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