Desempenho ambiental e económico de blocos de terra compactada estabilizados com cimento reciclado

Fábio Leonel Do Nascimento Romão

Key information

Authors:

Fábio Leonel Do Nascimento Romão (Fábio Leonel Do Nascimento Romão)

Supervisors:

Vitor Faria e Sousa (Vitor Faria e Sousa); José Alexandre De Brito Aleixo Bogas (José Alexandre De Brito Aleixo Bogas)

Published in

November 18, 2025

Abstract

The construction sector faces significant sustainability challenges due to its high consumption of natural resources and the greenhouse gas (GHG) emissions associated with concrete and cement. This dissertation evaluates the environmental and economic performance of compressed earth blocks (CEB) stabilised with recycled cement (RC), obtained from construction and demolition waste (CDW), and compares them with solutions based on Ordinary Portland Cement (OPC) and Limestone Portland Cement (LPC). The analysis quantified energy consumption, GHG emissions, and production costs, promoting the integration of circular economy principles in the sector. The methodology included modelling a case study, drawing analogies with lime production to estimate the RC process, applying Bond’s law for energy calculations, and using operational data provided by companies such as SGR, Vimajas, and Secil Agregados. The GHG emission factors highlight the impact of replacing clinker with RC. BTC produced with OPC generate 108.9 kgCO₂eq/t, and those with LPC 78.5 kgCO₂eq/t, whereas RC-stabilised BTC reduce this value to 24.3 kgCO₂eq/t, eliminating calcination-related emissions. From an economic perspective, RC-stabilised BTC show costs approximately 50% lower than OPC-based solutions, with additional advantages linked to the EU ETS and the Social Cost of Carbon (SCC). It is concluded that RC is a technically viable and environmentally advantageous alternative, although transport remains a critical factor requiring optimisation.