Nowadays, one of the most popular ways to get a more sustainable cement industry is using additions as cement replacement. However, there are many civil engineering applications in which the use of sustainable cements is not extended yet, such as special foundations, and particularly micropiles, even though the standards do not restrict the cement type to use. These elements are frequently exposed to the sulphates present in soils. The purpose of this research is to study the effects in the very long-term (until 600 days) of sulphate attack in the microstructure of micropiles grouts, prepared with ordinary Portland cement, fly ash and slag commercial cements, continuing a previous work, in which these effects were studied in the short-term. The microstructure changes have been analysed with the non-destructive impedance spectroscopy technique, mercury intrusion porosimetry and the “Wenner” resistivity test. The mass variation and the compressive strength have also been studied. The impedance spectroscopy has been the most sensitive technique for following the sulphate attack process. Considering the results obtained, micropiles grouts with slag and fly ash, exposed to an aggressive medium with high content of sulphates, have shown good behaviour in the very long-term (600 days) compared to grouts made with OPC.

This work represents a paradigm shift in the approach to manage port infrastructure maintenance where the use of the building information modeling (BIM) method is very scarce, and it is now beginning. The new infrastructure conservation management method proposed in this manuscript combines traditional methods with new technology, covering the gap of the implementation of BIM in port maintenance. This new technology is the BIM method, and its use is already mandatory in public infrastructure projects in some countries. In this work, the BIM method is applied to the management of the conservation of port infrastructures to show the benefits that can be obtained using it. After the analysis of the state of the art in the conservation of port infrastructures, two of the main maritime works of the Outer Port of A Coruña were modeled in Revit. This as-built model serves as an inventory model and forms a large database of all the information regarding the conservation of the structures. In this way, all the data on the conservation of the port’s infrastructures are concentrated in a single source of information in which, in addition, there is a three-dimensional and georeferenced representation of the port in question. The main finding of this work is the development of a step by step method to implement BIM philosophy in port maintenance, highlighting the positive and negative points detected during the validation of the method in a real case, detecting future improvement research lines. Although BIM has a lot of advantages and possibilities just now, some improvements are still necessary.

One of the most important consequences caused by the constant development of human activity is the uncontrolled generation of greenhouse gases (GHG). The main gases (CO₂, CH₄, and N₂O) are illustrated by the carbon footprint. To determine the impact of port infrastructures, a Life Cycle Assessment approach is applied that considers construction and maintenance. A case study of a port infrastructure in Spain is analyzed. Main results reflect the continuous emission of GHG throughout the useful life of the infrastructure (25 years). Both machinery (85%) and materials (15%) are key elements influencing the obtained results (117,000 Tm CO₂e).

Nowadays, the use of micropiles has undergone a great development. In general, they are made with cement grout, reinforced with steel tubing. In Spain, these grouts are prepared using OPC, although the standards do not forbid the use of other cements, like sustainable ones. Micropiles are in contact with soils and groundwater, in which the presence of sulphates is common. Their deleterious effects firstly affect to the microstructure. Then, the aim of this research is to study the effects of sulphate attack in the microstructure of micropiles grouts, prepared with OPC, fly ash and slag commercial cements, compared to their behaviour when they are exposed to an optimum hardening condition. The microstructure evolution has been studied with the non-destructive impedance spectroscopy technique, which has never been used for detecting the effects of sulphate attack when slag and fly ash cements are used. Its results have been contrasted with mercury intrusion porosimetry and “Wenner” resistivity ones. The 28-day compressive strength of grouts has been also determined. The results of microstructure characterization techniques are in agreement, although impedance spectroscopy is the most sensitive for following the changes in the porous network of grouts. The results showed that micropiles made using fly ash and slag cements could have a good performance in contact with aggressive sodium sulphate media, even better than OPC ones.

At present, sustainability is of major importance in the cement industry, and the use of additions such as silica fume as clinker replacement contributes towards that goal. Special foundations, and particularly micropiles, are one of the most suitable areas for the use of sustainable cements. The aim of this research is to analyse the effects in the very long-term (for 600 days) produced by sulphate attack in the microstructure of grouts for micropiles in which OPC (ordinary Portland cement) has been replaced by 5% and 10% silica fume. This line of study is building on a previous work, where these effects were studied in slag and fly ash grouts. Grouts made using a commercial sulphate-resisting Portland cement were also studied. The non-destructive impedance spectroscopy technique, mercury intrusion porosimetry, and Wenner resistivity testing were used. Mass variation and the compressive strength have also been analysed. Apparently, impedance spectroscopy is the most suitable technique for studying sulphate attack development. According to the results obtained, grouts for micropiles with a content of silica fume up to 10% and exposed to an aggressive sulphate medium, have a similar or even better behaviour in the very long-term, compared to grouts prepared using sulphate-resisting Portland cement.