Reduction of the Cement Content by Incorporation of Fine Recycled Aggregates from Construction and Demolition Waste in Rendering Mortars

Abstract

The construction sector is responsible for one third of the total wastes produced in the EU. Finding solutions for the reuse or recycling of these wastes is one of the major environmental concerns of modern times. The replacement of sand or cement in specific construction materials, such as concrete or mortars, is a possible solution for these wastes’ management. By using construction and demolition wastes in construction materials, namely on buildings, the cycle of circular economy is closed, increasing the life cycle of the wastes in the same sector. In this research, a reduction of cement content in rendering mortars is analysed. This reduction is achieved by a decrease of the cement/aggregate ratio simultaneously with the incorporation of very fine recycled aggregate from construction and demolition waste. Two recycled aggregates were studied: recycled concrete aggregate (RCA) and mixed recycled aggregate (MRA). The fresh and hardened state properties of the mortars were analysed. Several tests were carried out to evaluate the mortars’ performance, such as mechanical strength tests, water absorption tests, drying tests and shrinkage. It was noticed that the incorporation of RCA led to a better behaviour than in the reference mortar, in terms of mechanical strengths and protection against water.

Improving the Performance of Mortars Made from Recycled Aggregates by the Addition of Zeolitised Cineritic Tuff

“…Other researchers such as Saiz et al [8] and Katz and Kulisch [9] consider that recycled materials are more efficient when several recycled materials are mixed together. Duan et al [10], Duan et al [11], Jesus et al [12], Colangelo and Cioffi [13] and Ferreira et al [14] have managed to raise the mechanical strength of mortars made from ultrafine powder from bricks and calcinated clays, with proportions of 20 and 30%; they have also achieved good results by replacing part of the Portland cement, fly ash and natural sand in the concrete with recycled powders. A similar result has been obtained by De Rossi et al [15] in their investigations made with various sizes of fly ash particles to monitor the behaviour of geopolymer mortars in a fresh and hardened state, with a total substitution of normalised sand.…”

Influence of Recycled Aggregates on the Mechanical Properties of Synthetic Fibers-Reinforced Masonry Mortars

“…Sand is the second most consumed raw material in the world and its scarcity in some countries is expected to have an impact on the development of the construction sector [5,6]. For this reason, it is necessary to reconcile the industrial growth of nations with the preservation of the environment [7], in such a way that an effective recycling route for CDWs is their crushing, grinding and separation to be used as aggregates [8].…”

Prácticas de circularidad en la gestión de los Residuos de Construcción y Demolición en el sector de la construcción: una revisión bibliográfica de las estrategias y los elementos clave en su implementación

“…ISSN-L: 0020-0883. https://doi.org/10.3989/ic.92607 ticos y económicos (2,48,56). Es de mencionar que los RCD más comunes utilizados en los artículos seleccionados corresponden a concretos, morteros, ladrillos (13,42,52,55,87,92,100,111,117,118), seguidos de los residuos de drywall, madera y vidrios (51,87,92,117), Tabla 1.…”

“…Fases Total Diseño/ planeación Construcción Uso Restauración/ rehabilitación Deconstrucción/ Demolición (3,5,14,15,22,32,44,53,56,68,73,82,88,92,98,102,111,125) X X X X X 5 (4,20,33,40,49,50,80,100,115,120,126) X X X X 4 (69, 127) X X X X (128) X X X X (2, 7, 18, 34, 37, 47, 52, 55, 58, 70, 75, 78, 86, 87, 89, 93, 96, 98, 105, 109, 118, 124, 129,) X X X 3 (8,17,27,36,38,77,85,90,98,108,113,(130)(131)(132) X X X (10,11,16,42,48,51,…”