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In the last quarter of 2021, there was a very significant eruption of the Cumbre Vieja volcano on the island of La Palma, belonging to the Canary Islands, Spain. It generated a large amount of pyroclastic volcanic materials, which must be studied for their possible applicability. This work studies the properties and applicability of the lava and volcanic ash generated in this process. The need for reconstruction of the areas of the island that suffered from this environmental catastrophe is considered in this study from the point of view of the valuation of the waste generated. For this purpose, the possibility of using the fine fraction of ashes and lava as a supplementary cement material (SCM) in the manufacture of cement is investigated. The volcanic material showed a chemical composition and atomic structure suitable for replacing clinker in the manufacture of Portland cement. In this study, the cementing and pozzolanic reaction characteristics of unprocessed volcanic materials and those processed by crushing procedures are analysed. To evaluate the cementitious potential by analysing the mechanical behaviour, a comparison with other types of mineral additions (fly ash, silica fume, and limestone filler) commonly used in cement manufacture or previously studied was carried out. The results of this study show that volcanic materials are feasible to be used in the manufacture of cement, with up to a 22% increase in pozzolanicity from 28 to 90 days, showing the high potential as a long-term supplementary cementitious material in cement manufacturing, though it is necessary to carry out crushing processes that improve their pozzolanic behaviour.

La actual exigencia técnica del manejo de programas de diseño en el ámbito de la Ingeniería Civil y la Edificación lleva a plantear de forma indispensable la necesidad de formación de los futuros profesionales en la metodología BIM (Building Information Modeling).Mediante el presente Proyecto de Innovación Docente se ha desarrollado un modelo de implantación de esta metodología adaptándolo al programa actual de cada asignatura y a las competencias exigidas. La metodología y conocimientos teóricos y prácticos de las herramientas BIM han sido impartidos a 40 alumnos aproximadamente pertenecientes a tres títulos y niveles universitarios diferentes. Los resultados obtenidos muestran una evaluación satisfactoria por parte de los alumnos, respondiendo mediante la enseñanza de nuevas herramientas de diseño a las crecientes necesidades profesionales y enriqueciendo las habilidades de los estudiantes universitarios.

This work develops the manufacture of self-compacting concrete (SCC) with 50% cement reduction. As an alternative binder to cement, the viability of using an alkali-activated combination of stainless steel slag (SSS) and fly ash (FA) has been demonstrated. SSS was processed applying three different treatments. Binders were manufactured mixing 35% SSS with 65% FA, as precursors, and a hydroxide activating solution. This binder was replaced by the 50% cement for the manufacture of SCC. The results obtained show good mechanical properties and durability. The study shows a reduction in the use of cement in the manufacture of SCC reusing two wastes.

In recent years, the use of self-compacting concrete has been a great advantage and garnered undoubted interest in construction. Due to the environmental impact caused by the consumption of natural aggregates in the manufacture of concrete, a more sustainable approach is needed. An approach for more sustainable construction is to use industrial waste such as bottom ash from the combustion of biomass as a replacement for natural aggregates. This research aims to use biomass bottom ash as a replacement for natural sand (10%, 20% and 30% replacement); in addition, by utilizing a crushing process of the bottom ash, the ash has been used as a filler replacement (replacement 20%, 40% and 60%). The fresh and hardened properties have been evaluated according to the standard. The results show the feasibility of using biomass bottom ash in self-compacting concrete, providing a sustainable alternative in order to minimise environmental impacts related to the extraction and depletion of natural resources., FEDER/ Ministry of Science, Innovation and Universities—Agencia Estatal de Investigación (State Research Agency)/Valorisation of biomass bottom ash for sustainable construction applications (1264457-R)—BIOCEM

The use of industrial byproducts as construction material can help to achieve sustainability in this industry. Phosphogypsum (PG) is a waste obtained in the phosphoric acid (PA) manufacturing process, produced in large quantities, especially from the soil fertilizer industry. Alternatively, in the disposal of these materials in landfill, several investigations have applied PG as a substitute for natural gypsum in the production of Portland cement to control the hydration reaction rate of cement and also in concrete, bricks, plaster panels, and others. The composition and characteristics of PG are closely related to both the composition and origin of the feedstock used (phosphate rock), showing high gypsum content, and high levels of natural radionuclides, especially from U-series. These properties depend on the PA production process and the origin of the raw material. In this chapter, the possibilities of using this waste in cement-based materials are presented, to encourage future research lines based on this waste/byproducts.

Stabilization is a traditional strategy used to improve soils with the main objective of ensuring that this base is compliant with the technical specifications required for the subsequent development of different infrastructures. This study proposes the use of commercial nanomaterials, based on a solution of silicates, to improve the technical characteristics and bearing capacity of the expansive soil. A physical–chemical property study was carried out on the additive nanomaterial. Subsequently, different mixtures of expansive soil, selected soil and artificial gravel with quicklime and commercial nanomaterials were developed to evaluate the improvement obtained by the use of nanomaterials in the technical characteristics of the soil. Compressive strength and the Californian Bearing Ratio index were considerably increased. A full-scale study was carried out in which the nanomaterial product was applied to two different sections of stabilized road compared to a control section. The results obtained showed that the use of nanomaterial led to the possibility of reducing the control section by 30 cm, thus achieving less use of quicklime and a mechanical means for preparing the road section. The use of commercial nanomaterial improved the behavior of the stabilized sub-base layer. Through life cycle assessment, this study has shown that the use of nanomaterials reduces the environmental impact associated with soil stabilization., FEDER/Ministerio de Ciencia, Innovacion y Universidades-Agencia Estatal de Investigacion/Ecaryse RCT-2017-6202-5

The application of recycled aggregates (RA) from construction and demolition waste and crushed concrete blocks is a very important challenge for the coming years from the environmental point of view, in order to reduce the exploitation of natural resources. In Spain, the use of these recycled materials in the construction of road bases and sub-bases is growing significantly. However, presently, there are few studies focused on the properties and behavior of RA in civil works such as road sections or seaport platforms. In this work, two types of RA were studied and used in a complete real-scale application. Firstly, recycled concrete aggregates (RCA) were applied in the granular base layer under bituminous superficial layers, and secondly mixed recycled aggregates (MRA) which contain a mix of ceramic, asphalt, and concrete particles were applied in the granular subbase layer, under the base layer made with RCA. Both RA were applied in a port loading platform in Huelva, applying a 100% recycling rate. This civil engineering work complied with the technical requirements of the current Spanish legislation required for the use of conventional aggregates. The environmental benefits of this work have been very relevant, and it should encourage the application of MRA and RCA in civil engineering works such as port platforms in a much more extended way. This is the first and documented real-scale application of RA to completely build the base and sub-base of a platform in the Huelva Port, Spain, replacing 100% of natural aggregates with recycled ones.

The volume of slags generated from the steel industry is a source of possible resources which is constantly increasing. Specifically, in the production of stainless steel, specific and singular slags with unique characteristics are obtained, which allows considering an approach aimed at their use in new recycling ways. This work shows the feasibility of using stainless steel slag as a substitute for limestone filler in the manufacture of self-compacting concrete. The influence of different treatments applied to slags on physical and chemical properties was studied. On the other hand, the mechanical behaviour, as well as the durability acquired in self-compacting concrete, has been analysed. Very encouraging results were obtained, since this research demonstrates the possible application of this stainless steel slag as a construction material, improving sustainability and promoting circular economy processes, which are achieved through the minimisation of the waste disposal and accumulation.

Clay soils are widely distributed throughout the world and are the source of multiple technical problems in their application for the construction of sub-grade and sub-road bases. These types of soils are found in areas where civilian infrastructure such as roads and rural roads must be built. Therefore, in many situations it is necessary to use stabilized expansive soils, in the formation of the foundation and structural layers of linear infrastructures. Soil stabilization is used to increase the load capacity of the soil, and mixtures of lime and cement are generally used as binders. In recent years, interest in the recycling of industrial products and by-products has increased. One example of this is the use of biomass combustion in power plants. The management of significant amounts of waste (biomass bottom ash) from biomass power plants remains a problem. This paper presents the results of an experimental study for stabilizing expansive soil to determine its bearing capacity and mechanical properties via a triaxial test of the addition of biomass bottom ash. A double objective was targeted: reduction of the problems in using this type of soil and provision of a use for this type of waste. The results showed significant improvements in the mechanical. Therefore, herein is proposed the use of biomass bottom ash as a stabilizing agent for expansive soils, to improve the efficiency of the construction process by incorporating this product into a second life cycle as road bases.

This document studies replacing cement by stainless steel slag waste and improving the mechanical properties of the slag waste by using different types of treatments. The application of stainless steel slag waste reduces the use of raw materials for manufacturing cement and provides a profit from the large amount of waste generated. This study analyses the cementation and pozzolanic reaction characteristics of stainless steel slag waste to evaluate its strength activity index and its environmental impact. The cement was replaced with different substitution percentages of untreated stainless steel slag waste and slag waste that was processed through crushing, burning and both treatment to determine the optimum replacement ratio according to its mechanical properties. A study based on multivariate factor analysis was developed to compare these processed wastes according to their mechanical behaviour. The decision mechanism consists of a feature extraction method to evaluate the wastes used as a cement substitute.

The use of biomass for power generation is increasingly common. However, one of the most important problems when using biomass is the amount of waste produced in the combustion process such as ash, which must be transported to landfills for deposition. Biomass bottom ash may contain a large amount of organic matter which is the most restrictive property for reusing this by-product. The potential reuse is determined by chemical and physical properties. The presence of light particles and organic matter confer to biomass bottom ash certain physical and chemical characteristics which significantly reduce the possibility of reuse. Previous studies have demonstrated the possibility of using biomass bottom ash in cement-treated materials, but its properties imply a decrease of compressive and flexural strength. Therefore, this paper reported the study of the mechanical and durability properties of mortars containing biomass bottom ash applying different processing methods. Cement was replaced with different rates of substitution of biomass bottom ash and several samples were treated applying different techniques, such as grinding, elimination of lightweight particles and combustion. The results showed significant improvements in the mechanical and durability properties of mortars in which some treatment were applied. Lightweight particle extraction and organic matter removal by burning considerably improved the mechanical behaviour of the manufactured mortars. Therefore, mortars with crushed biomass bottom ash without floating particles and without organic matter led to a 10% of compressive strength decrease with respect to the control mortar. Thus, this study displays a possibility of waste valorisation by means of to the reuse of this type of by-product in mortars and concretes manufacture.

Recycled aggregates (RA) have been extensively studied in the production of concrete. Normally, the coarse fraction of recycled concrete aggregates (RCA) is the most commonly used to manufacture recycled concretes. The manufacturing of concrete with fine fraction of RCA and/or recycled mixed aggregates (RMA) (from a mix of concrete, asphalt, masonry, etc.) has not been studied in depth. In most cases, the recycling plants produce RA with an ALL-IN particle size distribution. These recycled materials could be named as ALL-IN RECYCLED CONCRETE AGGREGATES (aiRCA) and ALL-IN RECYCLED MIXED AGGREGATES (aiRMA). Applying these aiRCA or aiRMA, limiting the percentage of the substitution of natural aggregates (NA) by the aiRCA, is more beneficial for both the production costs and the environment. In recent studies, other by-products, such as biomass bottom ash (BBA) were used in concretes, substituting natural sand (NS) and improving the mechanical properties in concretes with low quantities of cement. It is possible to improve the properties of the BBA via mechanical processes (like screening or flotation) to reduce the organic matter content and there by obtain processed BBA (Pr-BBA). This study provides interesting data on the mechanical and durability properties of the concretes manufactured with 30% aiRCA and aiRMA, and also by applying different replacement rates (0, 15, and 30%) of NA by BBA and Pr-BBA. The mechanical and durability properties were analysed over different time durations in different mixtures. It was demonstrated that it is possible to apply these recycled materials in non-structural concrete mixtures by limiting the replacement rate. The application of BBA and Pr-BBA reduced the properties of the concrete. However, this reduction was less significant with the use of Pr-BBA.

In the last 15 years, new types of display technologies have increasingly replaced cathode ray tube (CRT) screens, which has led to an increase in landfill of old discarded CRT televisions, which present a great environmental challenge throughout the world due to their high lead content. In addition, environmental awareness has led to greater use of recycled aggregates to reduce the exploitation of existing reserves. This document aims to study the feasibility of incorporating CRT glass waste with recycled aggregate (RA) in combinations for use in civil engineering, more specifically in road bases and sub-bases. For the mechanical and environmental assessment of all of the samples and materials, the following procedures have been performed: the compliance batch test of UNE-EN 12457-4:2004 for RA, CRT, and mixtures, the Percolation Test according CEN/TS 14405 for the mixtures, CRT, and RA, Modified Proctor and load capacity (the California Bearing Ratio, or CBR) in all mixtures without cement addition, and finally, compressive strength of the material treated with cement at different ages of curing. The analysis of the mechanical and environmental properties through different techniques of lixiviation was positive, showing the ability to use CRT for certain dosage percentages mixed with recycled aggregates.

In recent years the use of biomass for electricity generation in thermal and cogeneration plants has increased worldwide because it is an environmentally clean fuel whose impact measured in greenhouse gas emissions is practically zero. However, biomass bottom ash, a waste produced during combustion, has also increased considerably, which has both a negative economic and environmental impact, due to landfill transport and management of this by-product. Although biomass bottom ash has potential characteristics for application in the manufacture of construction materials, its full-scale application is difficult because of the wide range in physicochemical properties, depending on the type of biomass burned, such as wood residue, olive waste, waste paper sludge, cocoa shell, etc., and the type of combustion process in the plant. This study reviews the influence on the physicochemical properties, mechanical behavior, and durability of different cement-based materials, such as mortars, concrete, and cement-treated granular material, manufactured from biomass bottom ash. The previous studies demonstrate the feasibility of substituting natural materials for biomass bottom ash in cement-based materials, presenting adequate mechanical behavior and durability properties to comply with the required technical specifications in different building materials.

Green philosophy is gaining popularity worldwide. Recycling materials from building demolitions, reutilizing by-products from industrial facilities and exploring the potential uses of waste during a second life cycle are the objectives of this philosophy. In the present article, bottom ashes from electric power generation plants using biofuel combustion were evaluated to verify their potential use as expansive clay stabilizers. Two objectives are pursued: (1) finding a new use for waste that is typically landfilled despite its great potential arising from its technical properties and (2) improving the mechanical properties and reducing the expansive nature of the expansive clays identified during the construction of a motorway. Based on this framework, the present study demonstrated the potential of biomass bottom ashes to stabilize expansive clays. The optimum dosage to improve the properties of clays was determined based on performance parameters, such as plasticity, free swelling or soil collapse. Afterwards, the contaminating potential of ashes was evaluated, being classified as hazardous waste. However, the stabilized mixtures were classified as inert products, thus guaranteeing the environmental feasibility of their use. Finally, the technical application of the stabilized clays as filling materials for embankments and subgrade for light traffic roads was proved. Graphical abstract.

Biomass is a renewable energy source that is increasingly being used worldwide. However, because of recent increases in production, waste products from biomass combustion are becoming a relevant environmental and economic problem. Other wastes from the construction and demolition sectors have been extensively studied. For this, several research studies have been performed to study the mechanical and some durability properties in concrete manufacturing with recycled concrete and mixed aggregates from different construction origins. In previous works, the lower density of recycled mixed aggregates (RMA) and biomass bottom ash (BBA) with respect to natural aggregates was studied. This feature can be exploited for the production of construction elements that require the use of low-density materials, such as lightweight concrete. For this, the aim of this work was to study the influence of the use of recycled mixed aggregates and biomass bottom ash, as replacements for the natural aggregates, on the mechanical behaviour, durability properties and environmental risk of recycled lightweight concrete. Several replacements for natural aggregates through recycled aggregates and biomass bottom ash were applied in the manufacture of lightweight concretes. To study the concrete behaviour, properties such as density, absorption, compressive strength, flexural strength, UPV, water penetration and drying shrinkage were measured. Due to the incorporation of RMA and BBA, a decrease of the density and mechanical properties of the recycled concrete manufactured was obtained with respect to the control mix. Therefore, the results showed the possibility of applying these types of recycled materials in lightweight concretes for their application in specific constructive elements. Through this study the possibility of reuse of waste and industrial by-products (RMA and BBA) that have so far been accumulated mainly in landfill is demonstrated. The positives results show the possibility of manufacture of lightweight concrete with these by-products, achieving a material with a lower density and mechanical requirements that comply with the current standards for concrete.

Several types of mixed recycled aggregates (MRA) from construction and demolition waste (C&DW) treatment plants in Cordoba and Malaga, Spain, and a sample of natural aggregate (NA) were studied to evaluate the viability of their use in the construction of road layers. The physicochemical properties, mechanical behavior and environmental impact of all samples were determined. The life cycle analysis of road sections manufactured with the materials studied was also determined. All samples of MRA showed a mechanical behavior suitable for use in the formation of road layers. In addition, it was determined that these materials, when they come from C&DW with selective collection at origin, cause less environmental impact than the impact caused by the use of natural aggregates in the formation of road layers.

Background:Rheumatic diseases are associated with accelerated atherosclerosis, and an increase in cardiovascular morbidity and mortality. This process is mediated by classic cardiovascular risk factors (CVRF), chronic inflammation and atherogenic treatments such as corticosteroids. In Systemic Sclerosis (SSc) cardiovascular complications have increased in recent decades, although the studies on subclinical atherosclerosis (sATS) in SSc show discordant results.Objectives:To evaluate prospectively the relationship between subclinical atherosclerosis, cardiovascular morbidity and mortality in patients with SSc.Methods:120 consecutive patients with SSc who attended their medical regular review during November and December 2011 were included. We evaluated the presence of plaques and measured the right CCA IMT by B doppler US for the detection of sATS (IMT> 0.9mm and/or presence of plaque), review of classic CVRF and estimation of Medsger severity and EUSTAR activity index. Patients have been followed for 8 years, with at least annual consultation. In retrospect, the SCTC damage index, published in 2019, was obtained at the time of inclusion in the study. The clinical characteristics of the patients are collected since 1990 in a Prospective Longitudinal Observational Study (PLOS). Descriptive analysis was performed, using contigence tables for qualitative variables, and comparison of means for quantitative variables. The relationship between clinical characteristics, mortality, cardiovascular events (CVE), activity, severity and damage index, and sATS, was analyzed using binary logistic regression, adjusting for age and sex.Results:120 patients with SSc were included (93% female, age 60 ± 12 years). 42 of these patients (35%) had subclinical atherosclerosis. Age was statistically significant higher in patients with sATS compared to those without it (67.9±11.5 vs. 56.1±10.4 years, p Table 1.Relationship between clinical characteristics and activity, severity and damage index with the presence of accelerated atheromatosis.Absent n=78Present n=42Diffuse cutaneous SSc37.18%26.12%NSmRSS7.71 ± 6.326.38 ± 4.92NSHigh mRSS9.69 ± 8.337.57 ± 4.74NSArthritis32.05%28.57%NSLung involvement33.33%30.95%NSPAH10.26%7.14%NSCardiac involvement15.38%9.52%NSDigital ulcers35.90%35.83%NSAntiScl7025.64%21.43%NSESR20.12 ± 13.7726.88 ±17.25p =0.037*CPR0.65 ± 0.610.89 ± 0.7p =0.041*High activity index11.54%19.05%NSDamage index6.67 ± 5.565.62 ± 4.9NSΣ Medsger index5.37 ± 3.55.05 ± 3.45NSConclusion:In our study subclinical atherosclerosis is not related to higher mortality in patients with SSc, but it does seem to influence the occurrence of cardiovascular events. In addition, our results suggest that SSc does not influence the onset of accelerated atheromatosis.Acknowledgments:M Retuerto was recipient of a training grant from Sociedad Española de Reumatologia (SER).Disclosure of Interests:M. Retuerto-Guerrero: None declared, MARIA MARTIN LOPEZ: None declared, Beatriz Joven-Ibáñez Speakers bureau: Abbvie, Celgene, Janssen, Merck Sharp & Dohme, Novartis, Pfizer, José Luis Rosales Grant/research support from: I have received financial support from Novartis, UCB, Pfizer, Abvie to meeting and symposia, Patricia Carreira Grant/research support from: Actelion, Roche, MSD, Consultant of: GlaxoSmithKline, VivaCell Biotechnology, Emerald Health Pharmaceuticals, Boehringer Ingelheim, Roche, Speakers bureau: Actelion, GlaxoSmithKline, Roche

In the last decades, several investigations have been developed on alkali-activated materials (AAM) with cementitious properties and for that reason also called binders, with a particular focus on the specific research areas of design and characterization of binders, mechanical behaviour and durability tests. Geopolymers consist of a polymeric framework of Si–O–Al, which is produced by condensation of tetrahedral aluminosilicate units, with alkali metal ions that balance the charge associated with tetrahedral aluminium. The geopolymers are usually synthesized from a two-part mixture, consisting of an alkaline solution (activator) and aluminosilicate solids (precursor), and the reactions occur at room temperature or slightly elevated. These materials can be used as cement and be applied in concrete and mortar. The excellent performance of cement and concrete with AAMs is attributed to the highly refined pore network, forming a denser structure phase of calcium aluminosilicate hydrate (CASH) or sodium aluminosilicate hydrate (NASH). In the last years, there was an intense development of studies focused on AAMs using traditional precursors such as waste-derived precursors such as blast furnace slag or coal fly ash, and synthetic ones as metakaolin. More recently, several research groups are testing different new waste as precursors and as activation reagents. The state of the art is focussed on precursors based on waste from urban, metallurgical, ceramic, construction and demolition and agro-industry activities. Regarding the activating solution, the state of the art also is focussed on waste derived reagents, differentiating between the cases in which the activating solution was prepared totally or partially from waste. Also recycled concrete aggregates (RCA) have been used with positive results in the manufacture of alkali-activated slag concrete (AASc).

A focus on environmental sustainability during the last decade has led to greater use of recycled aggregates to reduce the exploitation of existing reserves. In addition, environmentally consciousness has led to an increased use of renewable energy. Biomass is an important source of energy, and it also leads to high generation of waste products from biomass combustion. Previous studies have investigated the use of recycled aggregates from construction and demolition in road bases and sub-bases with positive results. This paper aims to study the feasibility of incorporating biomass bottom ash produced in the combustion process mixed with natural aggregates and recycled aggregates for use in civil engineering. The analysis of the mechanical properties was positive, showing the ability to use biomass bottom ash mixed with natural or recycled aggregates in specified ratios. Valuing biomass bottom ash can reduce waste generation and may lead to economic and environmental benefits.

Various treatments of phosphogypsum samples extracted in Huelva, Spain, curing conditions and incorporation ratios were studied to evaluate the viability of being used as set regulator or as supplementary cementitious material to improve the mechanical behaviour of cement mortars. The physical-chemical properties, mechanical behaviour and environmental impact of these phosphogypsum-based cement mortars were determined. It was concluded that the phosphogypsum treatments and curing conditions influence the mineralogical transformations of mortars and therefore also the mechanical behaviour of the mortars tested. Furthermore, the heavy metal impurities in the phosphogypsum were immobilized in the cement matrix, leading to a clear improvement of the technical properties of cement mortars made with this waste compared to the traditional use of natural gypsum.