Flexural behavior and properties of reinforced concrete beams made with recycled concrete aggregate

Abstract

With the dawn of twenty-first century, the world is focusing more and more on sustainable development. The construction industry has to fulfill the needs of the human society which is growing with time and to protect the environment. Many studies prove that the construction industry has played a big role in the degradation of the environment. Choosing construction materials has a major influence on the environment. In order to sustain the environment, the aim is to find a material that will allow the reduction of energy consumption and the elimination of the depletion of raw materials. Many studies found alternatives to the conventional raw materials to help preserve the natural resources but these materials are restricted in most cases to nonstructural components. The objective of this project is to investigate the effects of different replacement levels of natural coarse aggregates with Recycled Concrete Aggregates (RCA) on the flexural behavior of reinforced concrete beams. The purpose of this replacement is to reduce the harm done to the environment by the world`s most used construction material concrete. The project also studies the mechanical properties (compressive strength, tensile splitting strength, modulus of rupture and elasticity) of Recycled Aggregate Concrete (RAC). The properties of the recycled concrete aggregates are also studied and compared with properties of natural aggregates. The experimental program consists of four reinforced concrete beams: The first beam is the control beam which is made entirely with natural coarse aggregates (R0) and the three other beams are made with different replacement ratios of the natural coarse aggregates that are 50%, 75% and 100% (R50, R75, R100 respectively). The four-point loading test is used to determine the flexural behavior of these four beams. Thus, a conclusion on the behavior and properties of RCA concrete can be drawn based on the results of the experiments which vary with the replacement ratios of the natural coarse aggregates. RCA has a negative effect on the mechanical properties of concrete; a reduction in strength of concrete is observed.