Characterization of a lightweight concrete with sunflower aggregates

Abstract

The present study aim to develop an ecological and innovative material in the buildings area. Nowadays, the use of plant aggregates for sustainable development of building materials is a requirement for reducing the effect of pollution generated by the heating or cooling of buildings. Among vegetable aggregates, those obtained from sunflower stems were documented to sustain the obtaining of an ecological concrete with improved thermal and acoustical properties.In this research were obtained different variants of ecological concrete based on sunflower stalks as a partial replacement for mineral aggregates. There were determined the density and the mechanical properties of three variants of lightweight concrete comparatively to a reference concrete (RC) made with traditional sand and river gravel aggregates.The obtained results showed that the replacement of mineral aggregates in a proportion of 50% with the sunflower aggregates led in a decreasing of mechanical properties of the concrete with sunflower aggregates comparing to the reference mix. On the other hand, the treatment of sunflower aggregates with solution of sodium silicate resulted in a significant improvement of the compressive and tensile strengths of concrete comparing to the concrete manufactured with untreated sunflower aggregates. The mechanical properties of the concrete with vegetable aggregates were below the reference concrete, but the successful reduction of the water absorption capacity of the plant aggregates in parallel with the strength increasing of the resulted concrete, lead to the conclusion that sunflower stalk waste can be used as partial replacement of the aggregates in concrete composition.