**1. Introduction**

Concrete is the most widely used building material due to its strength, adaptability, low maintenance requirements during the lifetime of structures, and the economic and extended accessibility of its components [1], which makes it very difficult to replace in many infrastructure applications [2]. In fact, globally, concrete production is estimated at approximately 25 billion tonnes per year [3].

However, a relevant challenge is the amount of harmful emissions produced by concrete [4]. Actually, cement manufacturing and concrete production account for 6–9% of global man-made CO2 [5, 6]. Furthermore, by 2050, this value is projected to increase by 4% due to an increase of 12–23% in cement consumption [7]. Cement production generates, as well, high NOx and SOx emissions, which contribute to the development of acid rain, deterioration of public health and global climate change [8, 9].

Additionally, the high demand for natural aggregates used in the concrete mix generates a loss of vegetation and fauna, a decrease in air quality due to emissions of particulate matter, loss of fertile soil, risks of contamination of groundwater and deterioration of the life quality of people living near the extraction sites [10]. Furthermore, the extraction of aggregates can cause morphological alterations in the shape of the channel, bottom and banks, which has repercussions upstream through rebound erosion, generating a considerable increase in the velocity and shear stress of the flow and favouring the erosion processes in the riverbed [11].

The negative impacts related with the concrete material can be minimised by adopting a sustainable approach [12], where sustainability is understood as meeting the needs of the present without compromising the ability of future generations to meet their own needs [13]. In this context, sustainable engineering implies not only the use of sustainable materials, but a sustainable engineering system, where different engineering stages and processes can include factors such as reduction of environmental impacts, economic accessibility and access to the engineering solution regardless of the geographical location [14]. Therefore, from this holistic approach, the result is an alternative with ae technical, environmental, economic and social balance [15].

As important as it is, sustainability related with the concrete material is more than reducing the amount of cement in concrete mixes. Actually, sustainable characteristics have been reported by optimising the design of structures [16–18], replacing natural aggregate with different types of waste such as recycled crushed concrete, marble waste [19] or waste foundry sand [20] and incorporating nontraditional materials such as fibres [21, 22], biological material [23], hazardous waste material [24] or nanomaterials into concrete [25].

The objective of this book chapter is to analyse different types of contributions to a sustainable development using the concrete material. Although some examples are mentioned for the case of reducing the amount of cement directly in the concrete mixes, the analysis is focussed on the other approaches presented in Section 3 and analysed in Section 4 using different examples, most of them proposed from the concrete laboratory of the University of Concepción, Chile. Related with this, Section 2 presents the fundamental concept of geo-dependency, which is directly related with the development of practical and useful sustainable concrete alternatives.
