A Short Review on Lightweight Resilient Composite (LRC)

"Lightweight Resilient Composite (LRC)" is a lightweight compound material with its own structural particulars in which, contrary to the fundamental geometrical assumption of the flexural theory, the strain changes in the beam height during bending is typically nonlinear. This "Lightweight and Nonlinear Elastic Composite" can be considered a lightweight, methodically reinforced, nonlinear material also having a high specific modulus of resilience in bending.The matrix of LRC includes polymers and/or non-polymers like cement. E.g., a kind of LRC whose matrix is mainly cement-based is termed "Elastic Composite, Reinforced Lightweight Concrete (ECRLC)".By using LRC, with a significantly high strain capability, modulus of resilience and toughness in bending, we can get access to high bearing capacities in beams, with a safe failure mode, in less weight. Considering the properties of this "Lightweight and Nonlinear Flexible Composite" and its particular behavior in bending, the usual calculation of the balanced reinforcement ratio (ρb) to provide a safe failure mode in the beams and the respective limitations do not apply to LRC beams. Thereby, the dilemma of the high possibility of a brittle failure mode in the bending elements made of reinforced lightweight concretes, especially in those with low thickness and/or made of very low density concretes, can be removed.Such a "Lightweight and Nonlinear Resilient Composite" can have several applications, also in the road and building industries. In view of the strategic importance of "lightweight and integrated construction" in raising the resistance and safety against earthquake, the mentioned durable material can especially be useful in seismic areas. Allowing for the suitable behavior of this flexible system against impacts and dynamic loads, it is also feasible to make lightweight and insulating, non-brittle reinforced sandwich panels and pieces and lightweight, safe guards. Likewise, it can be utilized in making some retaining structures and the resilient pieces and constructions with an appropriate behavior and a high resistance against blasts, shakes, and shocks. Some kinds of LRC can be employed in constructing the vibration and impact absorber bearing pieces and slabs, which can be used in some railway and subway infrastructures too.This "Lightweight Nonlinear Composite" is produced by applying a particular method. Via this method, we can convert a rigid solid into a non-linear elastic material with less density or increase the elasticity of an elastic material along with reducing its density. This practical method generally involves creating an actually porous-like texture together with appropriately reinforcing the material as well as providing the necessary integrity. (Creating an actually porous-like texture can be done by generating the disseminated suitable hollow pores and/or distributing the suitable lightweight aggregates throughout the material.)In this paper, the main structural and functional specifications of the composites classified as "LRC" and some of their applications have been concisely reviewed. (By the way, some instances of such kind of composite, like ECRLC, have been shown.)

کلیدواژه ها:

Composites ، Nonlinear Elastic Materials ، Resilient Structures ، Porous-like Texture ، Methodical Reinforcement ، Lightweight Materials ، Strength of Materials ، Solid Mechanics ، Material Engineering ، Civil and Transportation ، Earthquake ، Lightweight and Integrated Construction ، Reticular ، Integrated ، Bendable ، Panels ، Cementitious ، Polymer ، Fiber ، Expanded Polystyrene (EPS)