Durability of Blended Cements Made with Reactive Aggregates.

Esperanza Menéndez,Hairon Recino,Cristina Argiz,Miguel Ángel Sanjuán,Ricardo García-Roves

doi:10.3390/ma14112948

Abstract

Featured Application In this paper, blended cements are proposed as an effective means of meeting the needs of mitigating climatic change. This proposal is a two-pronged strategy, i.e., durable and sustainable. The pozzolanic reaction of four binders is assessed, which is related to an alkali–silica reaction (ASR). Thanks to the findings made here, mix-design optimization can be performed. Alkali–silica reaction (ASR) is a swelling reaction that occurs in concrete structures over time between the reactive amorphous siliceous aggregate particles and the hydroxyl ions of the hardened concrete pore solution. The aim of this paper is to assess the effect of pozzolanic Portland cements on the alkali–silica reaction (ASR) evaluated from two different points of view: (i) alkali-silica reaction (ASR) abatement and (ii) climatic change mitigation by clinker reduction, i.e., by depleting its emissions. Open porosity, SEM microscopy, compressive strength and ASR-expansion measurements were performed in mortars made with silica fume, siliceous coal fly ash, natural pozzolan and blast-furnace slag. The main contributions are as follows: (i) the higher the content of reactive silica in the pozzolanic material, the greater the ASR inhibition level; (ii) silica fume and coal fly ash are the best Portland cement constituents for ASR mitigation.

Highlights

Published: 29 May 2021In response to meeting the global warming target of 1.5 ◦ C, signed in the Paris Agreement, an area of paramount concern regarding climatic change mitigation is that of reaching the goal of carbon neutrality [1]
Porosity of the porosities in the mortars made with the blended cements were found betwee Figure
Silica fume mortars followed a of the porosities in the mortars made with the blended cements were found between 12%

Summary

Introduction

In response to meeting the global warming target of 1.5 ◦ C, signed in the Paris Agreement, an area of paramount concern regarding climatic change mitigation is that of reaching the goal of carbon neutrality [1] Another key aspect of sustainable development is circular economy. Comprehensive national and international development strategies should be implemented for mitigating climate change and promoting circular economy, as do the roadmap to a resource efficient Europe [2] and the circular economy package in Europe [3], which include regulations for recycling 65% of global municipal waste by 2035, in line with the European Green Deal targets [1,3] These legislative initiatives will aim to make products fit for a climate-neutral circular economy that is resource efficient. Industrial wastes and by-products used in such cements should provide a durable and safe final product

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