Self-Compacting Recycled Concrete Using Biomass Bottom Ash.

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.

Feasible Use of Recycled Concrete Aggregates with Alumina Waste in Road Construction.

The management of different industrial by-products, such as recycled aggregates from construction and demolition waste and alumina by-products, as well as the reduction of landfill deposits by incorporating these products in a second life cycle, were the focus of this work. The aim of this study was to demonstrate the technical viability of using these waste and by-product as a material for road pavement base layers. For this purpose, a real-scale application was carried out, and the behavior of three types of materials, applied on a section of an experimental road under real vehicle traffic conditions, was studied and compared. Three materials were used in these sections applied in the road sub-bases. First, a control material composed of a type of artificial gravel was used to be compared with the rest of materials; the second material was composed of recycled aggregates, and the third was composed of a mix of recycled aggregates and alumina waste. The results concluded that the effectiveness of the sections built using recycled aggregates and alumina waste was very positive and similar those constructed using natural aggregates.

Management of Occupational Risk Prevention of Nanomaterials Manufactured in Construction Sites in the EU.

Currently, nanotechnology plays a key role for technological innovation, including the construction sector. An exponential increase is expected in its application, although this has been hampered by the current degree of uncertainty regarding the potential effects of nanomaterials on both human health and the environment. The accidents, illnesses, and disease related to the use of nanoproducts in the construction sector are difficult to identify. For this purpose, this work analyzes in depth the products included in recognized inventories and the safety data sheets of these construction products. Based on this analysis, a review of the recommendations on the use of manufactured nanomaterials at construction sites is performed. Finally, a protocol is proposed with the aim of it serving as a tool for technicians in decision-making management at construction sites related to the use of manufactured nanomaterials. This proposed protocol should be an adaptive and flexible tool while the manufactured nanomaterials-based work continues to be considered as an "emerging risk," despite the expectation that the protocol will be useful for the development of new laws and recommendations for occupational risk prevention management.

GIS environmental information analysis of the Darro River basin as the key for the management and hydrological forest restoration.

This article presents analyses of soil and environmental information for the Darro River basin (Granada-Spain) preliminary to its hydrological and forestry restoration. These analyses were carried out using a geographical information system (GIS) and employing a new procedure that adapts hydrological forest-restoration methods. The complete analysis encompasses morphological conditions, soil and climate characteristics as well as vegetation and land use. The study investigates soil erosion in the basin by using Universal Soil Loss Equation (USLE) and by mapping erosion fragility units. The results are presented in a set of maps and their analysis, providing the starting point for river basin management and the hydrological and forestry-restoration project that was approved at the end of 2015. The presence of soft substrates (e.g. gravel and sand) indicates that the area is susceptible to erosion, particularly the areas that are dominated by human activity and have little soil protection. Finally, land use and vegetation cover were identified as key factors in the soil erosion in the basin. According to the results, river authorities have included several measures in the restoration project aimed at reducing the erosion and helping to recover the environmental value of this river basin and to include it in recreation possibilities for the community of Granada. The presented analytical approach, designed by the authors, would be useful as a tool for environmental restoration in other small Mediterranean river basins.