Concrete-Based and Mixed Waste Aggregates in Rendering Mortars.

Samuel Roque,Catarina Brazão Farinha,Cinthia Maia Pederneiras,Rosário Veiga,Jorge De Brito

doi:10.3390/ma13081976

Samuel Roque, Catarina Brazão Farinha + Show 3 more

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https://doi.org/10.3390/ma13081976

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Abstract

This paper presents a study of incorporation of two types of construction and demolition waste (CDW) in rendering mortars, as aggregates at 0%, 20%, 50% and 100% (by volume). Recycled concrete aggregate (RCA) and mixed recycled aggregate (MRA) were used. The former is mainly composed of cementitious waste and the latter consists of a mixture of non-segregated wastes. The performance of the cement mortars with recycled aggregates was evaluated through an extensive experimental programme. The analysis comprised workability, mechanical strength, water absorption, shrinkage, open porosity and the evaluation of durability by permeability to water under pressure after an artificial accelerated ageing test. The results are considered positive, although as the incorporation of recycled aggregates (both MRA and RCA) increased the mechanical strength, the modulus of elasticity and bulk density decreased, which leads to the production of lighter mortars that are less susceptible to cracking. The modified mortar with 20% of MRA presented the best performance, in terms of mechanical behaviour.

Highlights

The construction sector has been considered the biggest waste producer in the European Union [1].As a result, the Waste Framework Directive 2008/98/EC of the European Parliament established that at least 70% of construction and demolition waste (CDW) should be recycled by 2020, in all the EU countries
Taking into account the lack of studies with mixed recycled aggregates (MRA) and recycled concrete aggregates (RCA) from actual plants in rendering mortars, the main objective of this research is to analyse the use of those two types of recycled aggregates from
Two types of construction and demolition waste were used in the experimental programme: recycled concrete aggregates (RCA) and mixed recycled aggregates (MRA)

Summary

Introduction

The construction sector has been considered the biggest waste producer in the European Union [1]. The Waste Framework Directive 2008/98/EC of the European Parliament established that at least 70% of construction and demolition waste (CDW) should be recycled by 2020, in all the EU countries. This regulation proposes appropriate processes to collect, transport, store, treat and dispose of the waste. The incorporation of recycled aggregates in cementitious materials is a possible solution for the disposal of these wastes, replacing the initial constituents and, simultaneously, avoiding landfill deposition of these raw materials. The scientific community has already started researching these applications and their introduction in mortars is growing [2,3,4,5,6,7,8,9,10,11,12]

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