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Trabajo presentado en: R-Evolucionando el transporte, XIV Congreso de Ingeniería del Transporte (CIT 2021), realizado en modalidad online los días 6, 7 y 8 de julio de 2021, organizado por la Universidad de Burgos, Mobility has been massively disrupted by new-generation telecoms and mobile apps, which allow an optimised utilisation of both transport means and infrastructures. When it comes to this kind of mobility, transport authorities and ‘traditional’ transport planning can only do little. Citizens step in and fill in the gaps at neighbourhood level by co-creating mobility solutions, as they already own or have at their disposal enough assets to work with: private and commercial vehicles, tracking and geo-location capabilities, smart communication devices, a transportation infrastructure grid and so on. Without additional investment in physical assets for marginal uses of the infrastructure, and without adding more vehicles to the streets, it becomes possible to ‘kick start’ a new mobility ‘metabolism’ through collaborative solutions that concatenate several ‘sharing’ approaches: car-pooling, car-sharing, crowd-parking, bike-sharing, cargo-pooling, data-sharing. In sum, crowd-sourcing and shared-economy ideas are turbo-charged by new technologies. Such technologies can bridge social capital and citizen power with the valuable aspects of free market economics. In addition, crowd-sourcing mobility solutions seem to make economic sense and bring democratic thinking and environmental conscience. But are they financially sustainable?

The European Green Deal and its endeavors will make rapid and far-reaching decisions with major implications for the European cement industry in the short- and longer-term. Accordingly, new measures should be dealt with quickly and effectively to minimize the adverse impact on global warming and global climate change by this sector. The aim of this study is to show and assess the measures to be undertaken to reach carbon neutrality by the Spanish cement industry by 2050. They may be categorized into three broad types based on the main materials: clinker, cement, and concrete. The cement sector must implement breakthrough initiatives, inventions, and technologies regarding the clinker and cement production processes. Furthermore, carbon dioxide uptake by cement-based materials must be considered to achieve the carbon neutrality objective. Accordingly, two methodologies named simplified and advanced, consistent with Guidelines for National Greenhouse Gas Inventories elaborated by the Intergovernmental Panel on Climate Change (IPCC), were selected to model the carbon offsetting by mortars and concretes. Finally, the existing climate change mitigation technologies available in Spain are insufficient to reach the net zero carbon footprint. Therefore, breakthrough technologies such as novel and efficient carbon dioxide capture, utilization, and storage (CCUS) technologies should be implemented by the Spanish cement industry to achieve zero carbon dioxide emissions in 2050.

The widespread use of solar-reflective concrete pavements can mitigate climatic change and urban heat islands (UHI) by cooling the pavement surfaces that are made of concrete instead of asphalt. The methodology that was followed is based on the comparison between the asphalt and concrete albedo effects in a specific application and area. In this study, we found that a reduction of temperature in the terrestrial surface, equivalent to the removal of 25–75 kgCO2/m2, could be achieved. Considering all the motorways and freeways of Spain, which is the third country in the world in km, a yearly equivalent carbon dioxide emissions reduction of 13–27 million tons could be reached. This value is quite high considering that the cement sector worldwide released about 2.9 Gigatons of carbon dioxide in 2016. Therefore, there is a positive balance in the use of concrete pavements. Furthermore, concrete is a material completely recyclable at the end of its service life and concrete pavement construction requires local resources, avoiding GHG emissions due to transport. An increase in the Spanish freeway network albedo by replacing asphalt pavements with concrete ones will improve the local climate change mitigation.

As the cement industry continues to address its role in the climate crisis, Portugal&rsquo, s cement industry has started to calculate its net CO2 emissions to become an entirely carbon neutral sector. These emissions are calculated by simply subtracting the total CO2 uptake due to mortar and concrete carbonation from the total CO2 that is emitted during the calcination process (clinker production). However, the procedures given in the Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas (GHG) Inventories to report GHG emissions do not contain any element that would grant this calculation method the status of an internationally recognized procedure. Therefore, some climate models are not accurate because they do not account for the carbon dioxide uptake due to concrete and mortar carbonation, as is evidenced in this paper. Climate models have improved since the IPCC&rsquo, s Fourth Assessment Report (AR4), but they can further improve by implementing carbon dioxide uptake by cement-based materials. In the present paper, a quick and easy method of evaluating net CO2 emissions is utilized (simplified method) along with an advanced method. Portuguese net CO2 emissions of the cement produced from 2005 to 2015 were calculated while taking carbon dioxide uptake during the service-life and end-of-life and secondary usage stages into account. Following the simplified method, 8.7 million tons of carbon dioxide were found to be uptake by mortars and concretes made with Portuguese cement over the ten-year period, in which 37.8 million tons were released due to the calcination process. In addition, an advanced method has been used to estimate the carbon dioxide uptake, which provided only slightly higher results than that of the simplified method (9.1 million tons).

The European parliament has declared a global &ldquo, climate and environmental emergency&rdquo, on 28 November 2019. Given that, climate change is a clear strategic issue all around the world. Then, greenhouse gas emissions are reported by each country to the United Nations Framework Convention on Climate Change (UNFCCC) every year. In addition, The Intergovernmental Panel on Climate Change (IPCC) in the &ldquo, 2006 IPCC Guidelines for National Greenhouse Gas Inventories&rdquo, give the procedure to calculate and manage the national greenhouse gases (GHG) emissions. However, these guidelines do not provide any method to consider the net carbon dioxide emissions to the atmosphere (released in clinker fabrication minus those due to concrete carbonation) by the Portland cement clinker industry. This topic should be implemented in the climatic models of the next IPCC assessment report. This paper provides an easy procedure of estimating net CO2 emissions proposed in the &ldquo, recarbonation project&rdquo, (simplified method), that is to say, carbon dioxide uptake during the service-life stage is considered as the 20% of the CO2 released by the calcination (process emissions), whereas the end-of-life and secondary usage is only the 3% of the CO2 released by calcination. The outcome of this study reveals that 31,290.753 tons of carbon dioxide will be absorbed by the cement-based materials produced in Spain with the cements manufactured from 2005 to 2015.

Standardization is beneficial for society in general and for research and innovation in particular. Standardization bodies as well as policymakers should promote the use of standards as a way of disseminating knowledge, exploiting research results and reducing time to market for the “innovation”. Several examples are presented here with regard to the standardization of research/innovation in the cement field. From cement manufacturing to nanotechnology applied to additives, cement and special concretes, it is possible to find good examples of innovation/research activities linked to standardization.

The International Energy Agency (IEA) predicts an important increment of primary energy demand until 2030. The electricity generation sector expects that world’s demand gets duplicated, which would mean the installation of new plants up to an additional global capacity of 5,000 GWe. This huge increment of the demand, together with other economic factors, will give fossil fuels (coal, gas and oil) a key role within the energy field.

The alkali–silica reaction (ASR) in concrete occurs by reaction of certain silica phases in the aggregates with alkalis and hydroxide ions in the pore solution of the hydrating cement to produce a hydrous alkali-silicate gel. This gel can swell by incorporating large amounts of water, causing severe and irreversible expansion and cracking of the concrete. The level of expansion and disruption in concrete containing reactive aggregate depends on the alkali content of the concrete and the reactivity of the aggregate. The levels of alkali that trigger the expansion depend, however, on the reactivity of the aggregates. Alkalis from Portland cement (OPC) are one of the major sources of these ions in concrete. The use of industrial by-products such as fly ash and slag has been found to be an effective preventive measure against ASR in concrete. This article presents the performance of biomass fly ash - an industrial by-product - in the mitigation/inhibition of ASR in concrete. Laboratory expansion tests were conducted to evaluate the performance of biomass fly ash, in replacement of OPC by 20% and 30% (w/w) in the experiments (ASTM C1260/ASTM C1567). The results revealed that biomass fly ash has a good potential in the expansion inhibition due to ASR. The authors wish to acknowledge Fundação para a Ciência e Tecnologia (FCT) for the financial support under project EXREACT PTDC/CTM/65243/2006) and PhD grant SFRH/BD/32500/2006. 1 4 7p DM/NMM 2011 3 a 8 de Julho

One of the most popular preventive measures to minimize the occurrence of chemical expansive reactions, namely the internal sulphate reaction (ISR), in hardened concrete is the use of mineral additions. This pathology is due to the formation of expansive ettringite (delayed ettringite formation - DEF) inside the material and is very difficult to deal with, because presently there is no efficient method to repair concrete structures affected by DEF. Hence, there is an urgent need to find preventive methods that may enable the inhibition of DEF in new constructions. Nowadays, it’s recommended the use of mineral additions to sustain this type of degradation. Moreover, their effect depends on the chemical and mineralogical composition and also the cement replacement. The research work presented in this paper deals with the influence of limestone filler, a type I mineral addition, in the inhibition of DEF (Santos Silva et al., 2010a, 2010b), and is part of an extensive study to elucidate the role that the mineral additions have in the mechanism of inhibition of DEF in concrete. For this purpose different concrete mixes were produced by using the same cement type (CEM I 42.5Ra with 3.11% SO3 and 6.4% C3A) and water/cement ratio (0.45), incorporating different amounts of mineral additions, like fly ash, metakaolin, blast-furnace slag, silica fume and limestone filler. The filler influence was followed by expansion and microstructure evaluation of concrete mix at several ages. These studies showed an interesting behaviour of limestone filler, which motivated new concrete formulations with different cement types (CEM I 42.5Rb and CEM I 52.5) that differ in SO3 and C3A contents, in order to investigate its influence in development of DEF. This research includes also a concrete composition with a cement type II (CEM II A-L 42.5R). The results obtained were compared and the conclusions were extracted. It was found that the concrete mixes with limestone filler showing higher expansions than the control composition. According to these results it seems that the limestone filler does not inhibit rather it promotes the expansion due to DEF. Thus, for concretes subjected to high temperatures in early ages, the limestone filler is not adequate to sustain DEF development rather it may even increase the expansion behaviour in concrete mixes. According to these findings, it was proposed that the ISR recommendations must prohibit this kind of mineral addition. The authors wish to acknowledge the Fundação para a Ciência e Tecnologia (FCT) for the financial support under project EXREACT (PTDC/CTM/65243/2006) and project DURATINET for Transnational Programme of Atlantic Area 2007-2013, co-financed by FEDER. 4 2 7 DM/NMM 2011 3 a 8 de Julho