Open AccessFeasibility Study on the Production of Sustainable Mortars Packaged with Recycled AAC Aggregates
Author(s) -
Maurizio Nicolella,
Alessio Pino,
Claudio Scognamillo,
Federica Vitale
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/960/4/042006
Subject(s) - mortar , masonry , lime , raw material , lime mortar , compressive strength , sustainability , flexural strength , materials science , waste management , environmental science , autoclaved aerated concrete , cement , composite material , civil engineering , metallurgy , engineering , ecology , chemistry , organic chemistry , biology
Building sustainability is one of the current global goals due to the variety and the quantity of the resources consumed in all the construction phases. Mortars – for masonry and plasters applications – are one of the most “produced” and high-impact composite building materials, since they are used both in traditional and modern constructions. Moreover, the production processes of binders and aggregates used to package mortars require the consumption of energy and resources and lead to the management of a huge amount of waste. In order to reduce the environmental weight of the mortars, the scientific world has been focusing, over the last years, on the substitution of natural aggregates with lightweight-recycled ones. Several studies have shown that this substitution improves some performances (thermal insulation and vapour permeability) and decreases other ones (compressive and flexural strength) as a result of the mortars density reduction. Moreover, the variability of recycled-aggregates materials (ceramic, plastic, concrete) and of the composition of mortars allows many different possibilities. However, little is known about the effective convenience of the market placement of these products. The aim of this study is to measure the environmental and economic sustainability of mortars made with natural hydraulic lime and a partial substitution of the natural sand with recycled aggregates from the production waste of Autoclaved Aerated Concrete bricks. These mortars were physically and mechanically characterized in a previous research phase and they were classified according to UNI EN 998-1 and 2. In particular, mortars with 25% by weight of AAC at most were suitable for masonry applications. The present study investigates the synergic possibility of packaging pre-mixes with recycled AAC aggregates in establishments where AAC is produced, moving from the unconventional perspective of the manufacturer. At first, LCA analyses are performed on these scenarios, in order to prove the strong decrease in the environmental impact of both production phases – AAC production, where waste is reduced, and mortar packaging, where the use of natural aggregates is limited – then the research moves to the analysis of the economic sustainability of the implementation of this production line. For this purpose, two cases are considered: an AAC manufacturer who does not produce pre-mixes, and an AAC manufacturer who produces pre-mixes, but does not own machineries to recycle Autoclaved Aerated Concrete bricks. Following a cost analysis related to the introduction of the production line of pre-mixes with recycled AAC in the two cases, hypotheses of market prices for this product are formulated in order to assess its economic sustainability, by performing a market analysis, and verifying the compatibility of the payback periods that derive from the related investments.