Effect of cement addition on the properties of recycled concretes to reach control concretes strengths

• Published in: Journal of cleaner production Vol. 79; pp. 124 - 133
• Main Authors: Beltrán, Manuel G., Barbudo, Auxi, Agrela, Francisco, Galvín, Adela P., Jiménez, José Ramón
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.09.2014; Elsevier
• Subjects: Animal, plant and microbial ecology; Applied ecology; Applied sciences; Biological and medical sciences; Cement; Compressive strength; Concrete; Conservation, protection and management of environment and wildlife; Durability; Environment and sustainable development; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Mechanical properties; Pollution; Recycled aggregates; Mechanical properties; Durability; Recycled aggregates; Concrete; Compressive strength; Cement; Pollution prevention; Recycled material; Recycling; Sustainable development; Environmental protection
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2014.05.053

Recycled aggregates from construction and demolition waste have previously been used to manufacture recycled concrete. Generally, these aggregates weaken the physical properties of concrete, such as the density, durability, compressive strength, flexural strength, water penetration, and chloride penetration. This is predominately attributed to the porosity of particles with adhered mortar or to ceramic particles. In other studies, cements with additions (fly ash, slag, silica fume …) were used to compensate for the effect of incorporation of recycled aggregates. In another, plasticizers were used to improve workability or mechanical properties of recycled concrete. However, the innovation of this research is the use of different amounts of cement according to replacement ratios of natural aggregates for recycled concrete aggregates to achieved structural concretes. Also, two different water/cement ratios were used to analyse if these reached compressive strength similar to control concrete manufactured with natural aggregates. The results revealed that a small increase in the volume of cement (12%) maintained the mechanical properties and reduced the loss of concrete durability. Therefore, increasing the amount of cement in recycled concretes is a feasible technique in works with low exposure to aggressive agents. •Recycled concrete manufactured with up to 100% of recycled aggregates.•Higher cement content to offset mechanical and durability losses recycled concretes.•Two different water/cement ratio to study this effect on two kind of concretes.•Similar strengths for each series due to increased cement.•Durability properties were slightly improved increasing amount of cement.