This section summarises the contents of some of the laws that comprise the regulatory framework applicable to the Construction and Demolition Waste (CDW) in Spain.
3.2. Chilean Reality
3.2.1. Political Constitution of the Republic of Chile
Point eight of Article 19 of Chapter III: On constitutional rights and duties, says that the Constitution ensures every person’s right to live in a pollution-free environment. It is the State’s duty to ensure that this right is not affected and to protect the preservation of nature. Laws may establish specific restrictions to the exercising of certain rights or freedoms to protect the environment [11
3.2.2. Chilean Law No. 19.300—Law on General Environmental Framework
A law approved by the Ministry of the Presidency in 1994. It establishes the legislative framework that regulates the right to live in a pollution-free environment, the protection of the environment, the preservation of nature and the conservation of environmental heritage. It also regulates the instruments for environmental management such as the Strategic Environmental Assessment, the Environmental Impact Assessment System and the Access to Environmental Information, the Liability for Environmental Damage, the Inspection and Environmental Protection Fund, and Chilean environmental institutionalism [12
3.2.3. NCh 3562: Waste Management—Construction and Demolition Waste and Excavation Material—Classification and Guidelines for a Management Plan
CDW are inert substances or objects, waste similar to that produced in the household and hazardous waste, which are generated during construction and/or demolition works and whose generator disposes of or has the intention or obligation of disposing of them in accordance with current legislation. The Management of CDW encompasses all the operative actions to which a construction and demolition waste is subjected to, including its gathering, stocking, transportation, pre-treatment, treatment and disposal.
This draft standard, prepared by the National Standards Institute [13
] (INN in Spanish) (Non-profit private law foundation created by CORFO in 1973, as a technical body on the issue of infrastructure quality control (Chile)), is currently in a public consultation process. Some of its objectives are:
Promote the integral management of inert waste and construction work excavation materials, to decrease their environmental, social and economic impact.
Promote the reduction, reuse, recycling and recovery of waste.
Ensure an appropriate waste classification and placement for the final disposal of the aforementioned waste.
It establishes basic considerations for the management of inert CDW from excavation, demolition or construction, which the various factors involved, must comply with, such as: Waste and excavation material generator (client and construction company), inert CDW manager (company or organisation that transports, recovers and disposes of it) and carrier of the excavation material for construction and demolition. Furthermore, it decrees the classification of waste from construction and/or demolition works and materials from excavation or roll forming. On the other hand, this standard does not establish basic considerations for the management of hazardous waste similar to that form households, which must be managed in accordance with current legislation.
This standard has 5
annexes, which are the following [14
ANNEX A: List of inert CDW;
ANNEX B: List of hazardous CDW;
ANNEX C: List of CDW similar to that from households;
ANNEX D: List of excavation material;
ANNEX E: Minimum contents of a Management Plan.
3.2.4. Chilean Law No. 20.920—Framework for the Management of Waste, the Extended Liability of the Producer and the Promotion of Recycling
It was passed on 17 May 2016 and then published on 1 June of the same year. The body responsible for this law is the Ministry of the Environment. The purpose of this law is to decrease the generation of waste and promote its reuse, recycling and other types of recovery, through the implementation of the extended liability of the producer and other waste management instruments, with the goal of protecting the health of the people and the environment.
The execution of this law was inspired by a series of principles, such as gradualism, inclusion, waste management hierarchy, the principle of “he who pollutes, pays”, free competition, the liability of the waste generator, transparency, traceability and disclosure.
For the purposes of the use and understanding of this law, it included a list of definitions. These are: Storage, life cycle, marketer, consumer, industrial consumer, distributor, ecodesign, disposal, generator, manager, management, reception and storage installation, handling, environmentally sound handling, best environmental practices, best techniques available, preparation for reuse, pre-treatment, priority product, producer of a priority product or producer, waste picker, recycling, collection, waste, reuse, management system, treatment, recovery and energetic recovery.
Chapter II of this law establishes everything related to waste management, such as prevention and recovery, obligations of waste generators, obligations of waste managers and obligations of waste importers and exporters.
On the other hand, Chapter III, named “of the extended liability of the producer”, is comprised of three paragraphs. The first details the general provisions, establishing the concept of “extended liability of the producer”, the obligations that priority product producers must comply with and the list of priority products. The second paragraph establishes the collecting and recovery goals and other associated obligations. Lastly, the third deals with everything related to waste management systems.
Chapter IV of this law details the support mechanisms for the extended liability of the producer, and lastly, Chapters V and VI establish the information systems and inspection and sanction regimes [15
3.2.5. Integral Management of Solid Waste Policy (PGIRS in Spanish)
This policy is born from the instructions provided by the Environmental Policy for Sustainable Development, approved by the Executive Council of the National Environment Commission (CONAMA in Spanish) in January 1998, which offered different tools to improve the deficiencies diagnosed in the current situation regarding waste handling, identifying the actions to develop, both in the short and medium terms.
The purpose of this policy is to guide the implementation of a hierarchical strategy, promoting the prevention of its generation and, if its prevention is not possible, to promote, in this order, its reuse, recycling, energetic recovery, treatment and final disposal, all for the purposes of protecting the health of the people and the environment.
Furthermore, one of the important points included in this policy is the suggestion of the need to have an integral management of waste, whose starting point is the very development of the product. This concept is already successfully implemented in a majority of developed countries and the main objective is to prevent its generation. In the case where this is not possible, minimisation measures are followed in a hierarchical and orderly manner. These are: Reduction, reuse and recycling; with treatment and final disposal as the last and least desirable option.
On the other hand, this management policy includes the different guiding foundations and principles that surround its development, as well as its different lines of action, which are the specific measures that allow compliance with and the success of the objectives proposed by this policy; and the regulatory framework, which establishes the goals to be reached in the short and medium term [16
3.2.6. Clean Production Agreement (APL in Spanish)
This is a voluntary agreement held between the representative corporate association of a productive sector and public bodies which are competent on several issues, the purpose of which is to improve the productive and environmental conditions in terms of hygiene and labour safety, energetic and hydrological efficiency, emission decrease, waste recovery, good practices, productive encouragement and other issues addressed by the agreement, looking to create synergies and economies of scale, as well as compliance with the environmental laws, which favour an increase in productivity and competitivity among companies.
To strengthen this tool, a key factor is the development of four Official Chilean Standards, which establish the guidelines for the development and implementation of, and accreditation of compliance with, Clean Production Agreements:
NCh 2797.Of2003 “Clean Production Agreements (APL)—Specifications”.
NCh 2807.Of2003 “Clean Production Agreements (APL)—Diagnosis, Monitoring and Control, Final assessment and Accreditation of compliance”.
NCh 2825, on “Requirements for the final assessment auditors”.
NCh 2796, on “Vocabulary” applied to this Accreditation System.
Since the year 2016, the National council for Clean Production has decided to publicly report the decreases of emissions achieved through Clean Production Agreements in accordance with the Directive of the Ministry of the Environment. Between the years 2012 and 2016, estimated reductions reached 3,242,301 tonnes of CO2
, making the APL the first Chilean mitigation action to report reductions back to the United Nations [17
3.2.7. Research Programmes Conducted in Chile
First Report on the Handling of Solid Waste in Chile (Based on the “Gathering, Analysis, Generation and Publication of National Information on Solid Waste in Chile” Project, Year 2010)
This report has been developed by CONAMA and summarises the main results of the “Gathering, analysis, generation and publication of national information on solid waste in Chile” project, completed in the year 2010.
In May of that year, Chile became the first full member of the Organisation for Economic Cooperation and Development (OECD) in South America. This status enforces a high standard on their public policies on environmental issues. With this, one of the commitments of Chile is to develop time series mainly associated to the generation, recovery and disposal of waste that facilitates the obtaining of indicators. The information exhibited in this report is part of the objectives of the Integral solid waste management policy. Furthermore, it meets the commitments that Chile has with the OECD regarding disseminating information on the handling of waste to the population. Among other sources, surveys, waste generation factors and diagnostic studies were referred to in order to conduct this report. The Government and the Ministry of the Environment have set as the main goal to continue improving on waste treatment issues. The ideal scenario is to enforce measures to stop seeing waste as rubbish, but instead as a raw material which can be minimised, reused and recycled.
This report is part of the “Gathering, analysis, generation and publication of information on solid waste in Chile” project, conducted in 2009. Its purpose is to deliver a general viewpoint of the amounts and handling of waste in Chile. The idea is to continue examining this information in coming years, in order to improve the national management standards.
As of the year 2005, through agreement No. 265 of the Council of Ministers of CONAMA, the country has:
The purpose of the Integral Solid Waste Management Policy is to guide the implementation of a hierarchical strategy, promoting the prevention of its generation and, if its prevention is not possible, to promote, in this order, its reuse, recycling, energetic recovery, treatment and final disposal, all for the purposes of protecting the health of the people and the environment. Likewise, among the lines of action until 2010, is to “Merge and complete the regulatory framework”. In regard to this there is the Waste Act (Chilean Law No. 20,92), which includes essential concepts such as: Hierarchical strategy, extended liability of the provider and integral management of waste.
Chile, by becoming a member of the OECD, must comply in the established terms, with an information structure associated to solid waste which takes into account a series of requirements regarding definitions, regulations and the cross-border movement of waste, among others. As of 2010, Chile has a new environmental government body comprised of:
Ministry of the Environment.
Superintendency of Oversight.
Environmental Assessment Service.
With the purpose of standardising the requirements, analysis and comparing of information on solid waste on an international level, the OECD suggested a detailed classifying of waste generation sources, which is linked to the classifications used in studies related to solid waste in Chile. Taking into account the main information structure available in the country and the separation of the source of the solid waste, they are classified as industrial solid waste and municipal solid waste [18
Final “Gathering, Analysis and Generation of Information on Construction Waste” (Solid Waste Group of the Pontificia Catholic University of Valparaíso PUCV) Report
Its purpose is to provide complete information on the generation and handling of construction waste in Chile, in order to meet the requirements enforced by the OECD.
Furthermore, the following points can be established as specific objectives:
Review the available information on construction and demolition waste.
Complete and update the information on the generation and handling of construction waste, specifying the amounts and associated characteristics.
Fill out the information requested on the OECD tables.
The executing of the following activities was requested in order to conduct this report:
To review the available information associated to construction waste on a national and international level.
To modify and update the information associated to construction waste in Chile.
To complete with the background information obtained from the model, the waste policy information on the OECD tables.
To study of the “Gathering, analysis, generation and publication of national information on solid waste in Chile” report.
On the other hand, different measures are suggested to be added to the PGIRS. These are born from the results and conclusions obtained during the development of this study and are suggested with the purpose of continuing to improve the development of future research. The first one is a summary table which includes several items, then their current development situation and, lastly, the desired situation or condition to be met. Lastly, different ideas are suggested to enable the obtaining of future information [19
Analysis of waste streams.
Waste generation estimate.
Assessment of the most favourable scenario for future management.
Third Report on the State of the Environment, 2017 Edition. Chapter 13: Waste
This report corresponds to the third instalment, corresponding to the year 2017, which delivers an update of the country’s environmental indicators and statistics, which makes it possible to monitor the evolution of the main components of the environment, as well as some of the problems that affect the country on this issue.
This report corresponds to the continuation of the first and second report on the environment, from the years 2013 and 2015, respectively. Likewise, as recommended by the OECD and as part of the advanced work on the issue of Sustainable Development Goals, as of this report, indicators are added which make it possible to measure the progress registered by the country regarding green growth, one of the great challenges in the medium and long term in order to promote an economic development which ensures the maintenance of the resources and the services they provide for people’s quality of life [20
Construction Waste in Antofagasta, Preliminary Study (by the Studies Unit of the Chilean Construction Chamber (CCHC in Spanish), in Antofagasta)
This study was conducted by the Studies Unit of the Chilean Construction Chamber (CCHC) in Antofagasta together with the work team from the Civil Construction degree of the Catholic University of the North, with the purpose of delivering a tool that helps improve the management of construction and demolition waste in this region.
A diagnosis of the current situation of construction waste management is submitted in this document. This assessment shows monthly generation indexes of these wastes, the role that construction companies must fulfil in the management of construction waste, and analyses potential options of locations to be used as final disposal points. Furthermore, an analysis of construction wastes, their origin, composition and classification are also submitted, as well as their optimal management and the review of an example of waste management both in Chile and abroad.
3.3. Interviews with Experts
shows the interviewed experts from the construction sector of Chile.
3.3.1. Roberto Tedias Araya (Construction Engineer, General Manager of the TVIAL Ltda. Construction Company), Jorge Fuentes Fuentes (Civil Engineer, Technical Manager of the Brotec Ltda. Construction Company)
They are both aware of the future shortage of aggregates in Santiago de Chile, which is why they see recycling as a solution. They argue that it could be used directly on site without a washing process, which is conducted in a laboratory in order to run tests. Their experience in the use of recycled aggregates has been with crushed granular base and subbase, with structural landfill or embankment.
3.3.2. Francisco Mora Frtiz (Civil Engineer, Metropolitan SERVIU)
He says that recycled aggregate is not considered a construction material in any Chilean regulations, and that adding it would be quite interesting considering the future shortage of natural aggregate in the metropolitan region. Metropolitan SERVIU is interested in including sustainability in its regulations, but the problem is that there is no document which allows its insertion in the institution. Documents that state both technical and environmental specifications on the use of recycled materials are required. His argument is based on the fact that, for now, it is not good business because it cannot compete with natural aggregate. His experience with recycled aggregates is the following: Filler for sewers and crushed granular base and subbase as an aggregate to manufacture concrete for footpaths. At the SERVIU they are aware of the NCh 3562 standard.
3.3.3. Gabriela Muñoz Rojas, Gabriel Palma Papic (National Roads Laboratory)
The National Roads Laboratory has applied the Rubblizing (Technique that consists of fracturing concrete pavement through resonance, in order to intertwine the wastes, turning them into crushed granular base or subbase), making it possible to obtain recycled aggregate to be used as crushed granular base and subbase in the same location. They have used recycled aggregates in embankments and other types of fillers.
3.3.4. Víctor Reyes González (Civil Engineer, Ministry of Public Works)
The Ministry of Public Works is aware that natural aggregate is gradually becoming a less and less available resource, and that there will be greater difficulties to extract it from deposits or quarries. The closest that has been done regarding the use of recycled materials, is the RAP (RAP: Recycled Asphalt Pavement (Asfalto Reciclado para Pavimento)). At the Ministry of Public Works there is an interest to include innovation in regulations, and for this purpose there is a defined protocol which makes it possible to submit technology proposals to a specialised unit, which awards the use of “test sections” through the National Roads Laboratory. The greater the use of recycled materials, the less exploitation of natural aggregates, which will lead to a decrease in the levels of CO2 released into the environment.
3.4. Technical Analysis
The materials considered in this study are concrete (for manufacturing roads), as well as crushed granular base and subbase (used as the support base in said roads as well as those built with asphalt). With a rising tide of adoption of recycled aggregate (RA) for construction, investigation on ways to improve the quality of RA has been overwhelming. The adoption of RA brings benefits including savings in the limited landfill spaces and the use of natural resources. However, the poorer quality of RA often limits its utilization to low grade applications such as sub-grade activities, filling materials and low grade concrete. The major reason that affects the quality of RA is the large amount of cement mortar remains on the surface of the aggregate, resulting in higher porosity, water absorption rates and thus a weaker interfacial zone between new cement mortar and aggregates, which weakens the strength and mechanical performance of concrete [21
]. The results of a recent study [22
] indicated that RA affect the resulting mechanical strength of hardened concrete due to the lower specific gravity and higher water absorption as compared to the natural aggregates (NA). Recycled coarse aggregate (RCA) has about 28% higher bonded mortar content (BMC) with porosity of bonded mortar (BM) almost double as that of recycled fine aggregate (RFA). This leads to inferior interface between aggregate and cement paste thereby affecting the overall concrete properties. The presence of mortar has been reported as the main factor causing the lower quality of recycled concrete aggregates (RCA) when compared to natural aggregates (NA). A novel microwave-assisted technique to increase the quality of RCA by partially removing the mortar adhering to RCA particles and breaking up the lumps of mortar present in RCA has been studied [23
]. The intrinsic properties of recycled coarse aggregates (RC), associated with bonded mortar, can be modified with two different pre-treatment techniques viz-a-viz HCl pre-treatment and Na2
]. Other authors report an experimental study to improve the properties of recycled concrete aggregates (RCA) by their impregnation with polyvinyl alcohol [25
Concrete: The Roads Manual (Document produced for the purpose of establishing policies and unifying procedures and instructions in the various technical areas to which they apply (Chile)) establishes a minimum resistance of 5.0 MPa to the bending tension test. According to this requirement, it would be hard to reach this resistance using 100% recycled aggregate, as its use requires a larger amount of water, and therefore has lower mechanical resistance. It is only possible to do this when using recycled aggregates that have been obtained by demolishing high-performance concretes. It cannot be used in these amounts, as a greater amount of cement has to be used, which would not make it feasible in economic terms. Additionally due to the high likelihood of being affected by shrinking, this would cause cracks. The recommended amount of demolition waste to use according to Spanish literature is up to 20% of the weight. One of the features to consider is the curing based on a superficial film (membrane curing), as well as the superficial saturation [26
To make it so that concrete with recycled aggregates reaches an ideal resistance, the surface of the stone material must have a minimum amount of adhered mortar. To do so, there are two possible methods to clean the said surface. The first is to wash it, which has the inconvenience of requiring a large amount of water, a resource that is currently scarce in the country and which would therefore noticeably increase costs. The other solution would be to implement a blower system, which makes it possible to clean the surface, but the problem is that doing so increases the levels of pollution, which is an equally critical factor in Santiago and the other regions [27
Crushed granular base: The Roads Manual establishes the need to obtain a CBR bearing ratio of 60%. The values achieved in this field in international literature are of the order of 40% for subbases, conducted with asphalt waste, and of around 60% when conducted with concrete demolition waste. The use of crumb rubber in certain proportions is also considered, in order to not compromise its structural stability. The structural properties increase even more if asphalt waste such as RAP is used [33
3.5. Result Analysis
Taking into account that which has been analysed, the following can be concluded.
3.5.1. Technical Legislation
In Spain there is technical legislation such as documents PG-3 and EHE-08, which consider the use of recycled aggregates, establishing limits, dosage and other aspects. In Chile however, current legislation only considers recycled materials in asphalt mixtures. The Roads Manual has specifications on the use of RAP, for example. However regarding the use of recycled aggregates, there is no legislation that allows its use in road works as of yet.
The interviewees mention that, in general, the construction sector is resisting considering the use of recycled aggregates, as there is distrust about its properties and a lack of knowledge on its benefits when used in road works.
3.5.2. Legal Legislation
In Spain there are laws that mandate the use of recycled materials and as well as penalising an inappropriate processing of CDW. The likely significant effects of projects on the environment must be considered in relation to criteria set out in points 1 and 2 of the Annex, with regard to the impact of the project on the factors specified in Article 3(1), taking into account, among other aspects, the possibility of effectively reducing the impact. [37
]. The different environmental assessment systems operating within Member States should contain a set of common procedural requirements necessary to contribute to a high level of protection of the environment. [38
]. The Public Administrations will adjust their actions regarding environmental assessment to the principles of institutional loyalty, coordination, mutual information, cooperation, collaboration and coherence [39
In Chile, despite the existence of laws that regulate and penalise the disposal of waste, they only reference other types of waste (domestic and organic, among others), leaving construction and demolition waste out of their reach. As per the comments made by the interviewed professionals, they say that, as there are no laws that make recycling mandatory, it is hard to create a sustainable culture in the construction sector. Furthermore, within the administrative bases there is also no requirement to use recycled materials, not even a certain percentage.
Chilean Law No. 19.300;
Chilean Law No. 20.920;
NCh 3562: Waste Management;
Integral Solid Waste Management Policy (PGIRS)
Clean Production Agreement (APL);
Research programmes carried out in Chile.
3.5.3. RESCON Management Plan
In Spain, the CDW management plans are set, and have been dealt with since the year 2008 through Spanish Royal Decree 105/2008, whereas in Chile the only requirement is a certificate that states that the dumping site is one that has been authorised. There is no law that mandates the establishment of a plan to manage waste generated in works. Standard NCh 3562 tries to solve this situation.
3.5.4. Ministerial Structure
There is an entity known as the Ministry of Public Works and Transport, which branches out into several Departments and Administrations. The General Administration of Architecture, Housing and Land, and the General Administration of Roads, are those responsible for Urban Roads and Interurban Roads, respectively (Figure 2
There is no responsible entity such as the mentioned Spanish one (Figure 2
). There are only Ministries of Housing and Urban Development (which, through the SERVIU, is responsible for Urban Roads) and the Ministry of Public Works (responsible for Interurban Roads).
In Spain, the CDW plans (PNRCD I, PNRCD II, PEMAR) establish the objectives for CDW in each respective application period, as mentioned in Table 1
and Table 2
. Furthermore, the PEMAR (2016–2022), establishes the number of permanent and mobile plants and dumping sites, as can be seen on Table 5
On the other hand, in Chile there are only two companies related to CDW. One of them is RESICO, where recycled aggregates are produced from concrete waste and which are then commercialised in two sizes (3” and 1½”), and the other is REGEMAC, a company which transfers this construction waste to authorised dumping sites.
In Spain there are different treatment plants and dumping sites.
In Chile there are only a few companies dedicated to recycling concrete aggregates (Table 6
3.5.6. Implementation of Recycled Aggregates
In Spain, the use of recycled aggregates has become standard practice, to the extent that this type of material is in the market, and with seals of quality. This situation makes it possible to define a wide variety of implementations, such as granular base and subbase, the manufacturing of test pieces (with a quality of up to G-40) (In accordance with Chilean standard NCh 170, Of. 2016 “Concrete—General Requirements”. Mechanical resistance to compression is measured in Degrees, in cylindrical test pieces with a 15 cm diameter and 30 cm height.), concrete prefabs, fillers and embankments, among others.
Meanwhile, in Chile, the interviewed professionals mention a series of implementations such as granular base and subbase. The benefit of this context is that demolition waste can be used immediately, as it can be crushed in situ and then installed right away in the area where the future road project will be executed, aside from the fact that studies back this way of using this type of waste. When dealing with concrete pavement waste, bearing ratios close to 80% can be obtained, whereas asphalt pavement waste can reach a CBR value of 40% at most, which is why its use is limited to granular subbase.
On the other hand, the use of recycled aggregates is not recommended for manufacturing concretes, due to the low resistance levels obtained in tests conducted in their installations, coinciding with the observations made by the construction companies. In practice, the interviewees mention that, despite there being several methods for applying recycled aggregates in works, and the will to apply sustainability in the sector, there are factors that hinder its execution, as in Chile there is still no specific sustainable culture, a process which is currently being developed.
3.5.7. Solutions Proposed by the Experts
the following products are manufactured for construction:
Concrete test pieces (with a quality of up to G-40);
Securing and covering of pipes;
Prefabricated pieces of concrete;
Cement floor and cement gravel.