Construction and Building Materials 40 (2013) 1168–1173

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Construction and Building Materials

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Production of recycled sand from construction and demolition waste

C. Ulsen a, H. Kahn a,⇑, G. Hawlitschek a, E.A. Masini a, S.C. Angulo b, V.M. John c

a Department of Mining and Petroleum Engineering, Polytechnic School, University of Sao Paulo. Av. Prof. Mello Moraes, 2373, CEP 05508-030 São Paulo, SP, Brazilb Institute for Technological Research. Av. Prof. Almeida Prado, 532, CEP 05508-901 São Paulo, SP, Brazilc Department of Construction Engineering, Polytechnic School, University of Sao Paulo. Av. Prof. Almeida Prado, 83, CEP 05508-900 São Paulo, SP, Brazil

a r t i c l e i n f o a b s t r a c t

Article history:Available online 14 March 2012

Keywords:Recycled sand productionConstruction and demolition wasteMineral processing

0950-0618/$ - see front matter � 2012 Elsevier Ltd. Adoi:10.1016/j.conbuildmat.2012.02.004

⇑ Corresponding author. Address: Departamento dPetróleo da Escola Politécnica da USP, Av. Prof. Mello MSão Paulo, SP, Brasil. Tel.: +55 11 3091 5151; fax: +55

E-mail addresses: carina@lct.poli.usp.br (C. Ulsen(H. Kahn), gustav@lct.poli.usp.br (G. Hawlitschek), escangulo@ipt.br (S.C. Angulo), john@poli.usp.br (V.M.

Existing construction waste recycling technologies and standards have long been applied in constructionand demolition waste recycling. However, they have been essentially focused on the production and useof coarse recycled aggregates. This paper presents a technology that permits the production of high qual-ity recycled sand. The selective removal with a vertical impact crusher of the cement paste attached torecycled aggregates and the potential improvements in the quality of the recycled sand that is producedwere investigated. The results showed that the proposed method permitted the production of low-poros-ity sand from construction and demolition waste and may contributes to changing the construction recy-cling model.

� 2012 Elsevier Ltd. All rights reserved.

1. Introduction

The composition of construction and demolition waste (CDW) isdictated by different construction types and their components; ingeneral, CDW is composed of concrete, asphalt, brick and ceramicmaterials [1]. The problems related to waste dumping have dra-matically increased with the growth and development of large cit-ies. In the UK, for example, over 50% of landfill waste comes fromconstruction use [2] and the US alone produces around 200–300 million tons of CDW annually [3]. The exhaustion of naturalsand deposits close to large urban centers necessitates the initia-tive to use CDW as a potential raw material.

Previous studies have shown that the fine fraction (particlesbelow 4.8 mm) represents about 50% of the weight of the crushedC&D waste in coarse recycled aggregates production [4]. For along time, the fine fraction was disregarded or used as a roadpavement base because it was believed to have low qualityproperties. However, regardless of any limitations that may exist,the use of recycled aggregates in concrete will be essential in thevery near future [5]. As well, recent studies have shown that finefraction properties are not that different from coarse fractionproperties, and can even be improved with appropriate processing[6]. Experimental tests have shown the viability of the partialreplacement of natural sand by crushed bricks in the mortarproduction [5,7].

ll rights reserved.

e Engenharia de Minas e deoraes, 2373, CEP 05508-030,11 3091 6037.

), henrique.kahn@poli.usp.bramfsini@usp.br (E.A. Masini),John).

The quality of the recycled aggregate is strictly related to thecontent of porous and low strength phases as well as the patchesof cement that remain attached to the recycled aggregate. Thisphase accounts for the increase in water absorption, which length-ens mixing time and affects the strength of the recycled aggregates[5], in particular in replacement of virgin aggregates over 15–20%of coarse (op. cit.) or fine aggregates [8].

The specific surface area directly influences water demand andconsequently increases cement consumption in a set water/cementratio [2]. If the same cement ratio is maintained, the free water inthe cement paste rises and there is an increase in porosity [5]. Kruset al. [9] explained this by considering that water is a strong polarliquid and can thus slip between the mineral layers of the cementpaste and widen the distances between them, allowing new porespaces to be created.

The removal of adhered cement paste is a crucial factor foraggregate performance, and this is not a simple task. The literatureshows that it can be achieved by successive comminution stages[10], thermal treatments [11,12] or electrical discharge [13,14].However, so far, none of these technologies have actually managedto reach the large available market.

Mineral processing has been long applied to CDW recycling,although few authors focus on the production of recycled sand.On the other side, the production of sand from crushed stone (arti-ficial sand) has been conducted for over a decade by vertical shaftimpactors (VSIs). This equipment consists of a rotor revolving athigh speed. The rotor centrifugally throws the material into thecrushing chamber where the comminution occurs by rock-on-rockimpact, attrition and abrasion [15]. The main advantage of the VSIcrusher is its ability to produce cubic particles in all size fractions,contributing to a better aggregate morphology [16,17].

C. Ulsen et al. / Construction and Building Materials 40 (2013) 1168–1173 1169

Regarding the use of VSI, some operational advantages deserveto be mentioned here: control of product size distribution by rotorrotation [17]; low labor costs; the fact that it does not crush thefines; and consumption of 6% less energy than the conic crusherfor the same feed rate [18]. The rotation (rotor speed) is the param-eter that mostly influences the shape, size distribution and poros-ity of aggregate particles [17].

The selective removal of the cement paste attached to recycledaggregates by a vertical impact crusher and the potential improve-ment in the quality of the recycled sand produced were investi-gated. The main properties of recycled aggregates are discussedand compared to the previous C&D waste.

Fig. 2. Laboratory procedure.

2. Experimental

2.1. Sampling

The investigation was carried out on C&D waste from ‘‘Urbem Tecnologia Ambi-ental,’’ a private recycling plant located in the city of Sao Bernardo do Campo in theSao Paulo metropolitan region in Brazil. The composition of the waste was basicallylow and medium-strength concrete (around 80%) and masonry.

The operational flowsheet of the plant is summarized in Fig. 1. It consists of avibrating grizzly to remove the fractions below 4.8 mm before crushing (C&D sandfraction), comminution by impact crusher, magnetic separation to remove theremaining steel bars, and finally, a two-deck screen to perform the dry sievingand grading of the products into three size fractions: <6.3 mm, 6.3–39 mm and39–150 mm. The organic materials such as paper, wood, plastic and others are re-moved from the mineral fraction by hand sorting, either before or after crushing.The attained products are commercialized for base pavement applications; fraction<4.8 mm have limited marked and sometimes are sent to landfill.

The sampling procedure was replicated twice a week for 60 randomly selecteddays. The samples were collected at the four product stock piles in the same propor-tions as they are produced (2:5:2:3 as shown in the flowsheet). An average sampleof the four products was composed by mixing all aliquots (Urbem CDW). The totalmass collected was about 4 tons.

The experimental flowsheet is shown in Fig. 2 and described below, as are thecharacterization procedures.

2.2. Crushing

The total sample (about 4 tons) was comminuted in a laboratory jaw crusherwith a closed circuit screen to obtain a product below 19 mm (3/400), which washomogenized by horizontal elongated piles [19]. A secondary sampling was per-formed for the attainment of three representative and equal aliquots.

Each aliquot (below 19 mm) was crushed by a vertical shaft impact crusher(VSI) at different rotor speeds, respectively 55, 65 and 75 m/s, with a closed circuitwith a 3 mm aperture screen. The tests were conducted on a Barmac 3000 at theMetso Process Technology Centre in the city of Sorocaba, São Paulo, Brazil.

Fig. 1. Flowsheet of Urbem recycling plant.

2.3. Products characterization

The characterization procedure was conducted on the head sample (<19 mm),on CDW-sand (fractions <3 mm obtained by the head sample sieving) and on theVSI products.

The main parameters to be characterized were particle size distribution, parti-cle shape, chemical composition, cement paste content, distribution in density clas-ses from heavy liquid separation, water absorption, specific surface area andporosity. The objective of the product characterization was to compare the mainproperties of the recycled sand with the previous C&D waste.

Particle size distribution was determined by wet sieving for more accurate re-sults. The objective was to evaluate VSI conditions and the amount of fines gener-ated below 0.15 and 0.074 mm and to also make a comparison to the original CDWsand fraction.

The particles shape was evaluated with dynamic image analysis on a QICPIC realtime particle analyzer (Sympatec) to assess the influence of the attrition and abra-sion crushing on particle sphericity as well as to compare the effects of the rotorspeed.

The chemical analyses were carried out by quantitative X-ray fluorescence at aAxios spectrometer (PANalytical) in fused beads and the loss on ignition was as-sayed at 1050 �C.

The distribution in density classes was performed by heavy liquid separation.The procedure consists of placing a sample in a heavy density organic liquid. In thissituation, the light particles float and the heavy particles sink, which separates par-ticles with different porosity and oven-dry density, parameter that influences themechanical properties of the aggregates [20].

The measurement of the water absorption for fine aggregates is usually per-formed according to ASTM C 129. However, the standard method has long been crit-icized since the remains of cement paste affect the results of the experiments thatwere designed for ordinary natural aggregate [2]. Water absorption was thus mea-sured according to the methodology proposed by Daminelli [21]. This methodologyconsists of saturating the pores with water using a vacuum system and then dryingthe sample with a microwave. The loss of weight has to be measured constantly.Graphing the drying rate versus time and the drying rate versus moisture allowsthe parameters to be determined for calculating water absorption, such as dry mass,saturated surface dry mass and mass under water.

Scanning electron microscopy (SEM; Quanta 600 FEG, FEI) coupled with an en-ergy disperse spectrometer (EDS; Quantax, Bruker) was used to characterize thephases association through backscattered images and X-ray digital mapping forthe major elements (Si, Al, Fe, Na, K, Ca).

3. Results and discussion

3.1. Effect on particle size distribution

The particle size distributions of the characterized products areshown in Fig. 3.

Fig. 4. Sphericity classes of recycled sand from CDW; absolute and cumulativefrequency of particles.

1170 C. Ulsen et al. / Construction and Building Materials 40 (2013) 1168–1173

The CDW head sample represents the aggregates after the sec-ond crushing stage at Urbem recycling plant (crushed < 19 mm).Around 50% of this product’s weight is below 4.8 mm (sand frac-tion) and 6% is below 0.15 mm. Regarding just the fraction bellow3 mm of head sample, named as CDW-sand, it has 15% of its weightbelow 0.15 mm.

The comminution of the CDW head sample in a vertical shaftimpactor (VSI) at three different rotor speeds produced sand withsimilar grading (Fig. 3), and featured a subtle decrease in the finefraction percentage at the lowest speed. Furthermore, the VSI ter-tiary crushing did not noticeably increase the amount of fines, so itcan be concluded that the sand produced by tertiary crushing atVSI has quite a similar size distribution to the CDW-sand fraction(Fig. 3).

3.2. Shape analysis

The shape analysis results of VSI products and the CDW-sandfraction are summarized by the frequency of particles with certainEQPC (diameter of a circle of equal perimeter) for each class ofsphericity. Comparative results are shown in Fig. 4.

Since the sphericity of particles for the three crushing condi-tions is very similar, the effects of rotor speed on the VSI crushedsand are very subtle. On the other hand, the sphericity of CDW-sand is rather different from the VSI crushed sand. In conclusion,rock-on-rock crushing improved the morphology of recycled sandas compared to the sand fraction from C&D waste. However, the ro-tor speed did not greatly influence particle shape.

3.3. Chemical composition of the main oxides

The composition of fractions of the recycled aggregates above0.15 mm is represented mainly by silica (65–75%), calcium oxide(7–11%), alumina (6–10%) and iron oxide (around 2.5%). Loss onignition is around 6 to 9% on average. Minor compounds areNa2O (0.5–2%), K2O (1.5–3%) and MgO (1–2%). Adding togetherthe SiO2, Al2O3, Fe2O3, CaO and LOI grades exceed 90% of the totalcomposition. The fractions bellow 0.15 mm represents between15% (CDW-sand) and 20% (VSI-sand) of the total weight and hasa different composition with a remarkable decreasing on silica con-tent (48–53%) and increasing on calcium oxide (15–17%) and LOI(12–15%).

The sum of the silica, alumina and iron oxide grades can be cor-related to the content of silicates from natural rock phases, sandand ceramics while the sum of the grades of calcium oxide andthe loss on ignition is directly related to the binder content [4].

Fig. 3. Particle size distribution of each product. CDW – head sample; CDW-sand –fraction <4.8 mm from the head sample, VSI-55, 65, 75 – sand produced fromtertiary crushing by VSI crusher in different rotor speed.

The comparative analysis of the content and distribution ofCaO + LOI for fractions above 0.15 mm for each product is shownin Fig. 5. Distribution means the proportion of some compoundin such a fraction or product in relation to the total content ofthe whole sample.

In this sense, almost 90% of the total content of CaO + LOI is pre-sented at a fraction above 0.15 mm for the CDW head sample,while the sand fraction for the same product represents 87% ofthe total CaO + LOI. For VSI crushed sand, the amount of the samephase is reduced to values of 67.6–62.5% for the same fractions.

These results are consistent with the previous ones and showthat the cement paste concentrates at the fine fractions. Moreover,the distribution curve decreases more abruptly than the mass dis-tribution, indicating an enrichment of cement paste for fine frac-tions. The crushing rotor speed did not have a crucial influenceon chemical composition; the results for the three speed rotor testswere quite similar.

The relative proportion of quartz and aluminum silicates (mainlyfeldspar) can be seen in the ratio between the SiO2/(K2O + Na2O)grades, as presented in Figs. 6 and 7. The quartz is related to sandand crushed stone while the aluminum silicates (mainly feldspar)originate from crushed stone (essentially granite).

The results of the head sample (Fig. 6) indicate a remarkable in-crease of quartz grades in fractions of between 2.0 and 0.15 mm.The increase in Na2O + K2O grades in relation to SiO2 highlight that

Fig. 5. Comparative weight, CaO + LOI grades and distribution. Grade (or content) isthe percentage weight of each constituent; distribution means the proportion(percentual values) of each constituent in such fraction or product.

Fig. 6. Relative proportion between quartz and aluminum silicates of CDW.

Fig. 7. Relative proportion between quartz and aluminum silicates for CDW-sandand VSI-sand.

Fig. 8. Comparative weight percentage of sink product.

Fig. 9. Comparative weight distribution on sink product, associated content (grade)and distribution (proportion) of CaO + LOI in each product.

C. Ulsen et al. / Construction and Building Materials 40 (2013) 1168–1173 1171

VSI-sand (Fig. 7) incorporates aluminum silicates from the coarseaggregates during the comminution process.

Regarding the sand produced by VSI crushing (Fig. 7), the rotorspeed also appears to affect the ratio between quartz and other sil-icates. On fractions above 0.30 mm, the SiO2/Na2O + K2O ratioclearly shows that the quartz content decreases inversely to the ro-tor speed and then the aluminum silicates content increases. Thisbehavior indicate a selective comminution of the binder phase(quartz plus cement paste) the higher the rotor speed.

In conclusion, the content of cement paste diminishes in frac-tions below 1.2 mm and above 0.15 mm and increases noticeablyin fractions below 0.15 mm, indicating that the cement paste tendsto concentrate in the finest fraction sizes. The crushing of CDW be-low 3.0 mm leads to a recycled aggregate relatively enriched inaluminum silicates content when compared to the CDW-sand.Moreover, the faster the VSI rotor speed the higher the grade ofaluminum silicates on fractions down to 0.30 mm. The fraction bel-low 0.15 mm is enriched on cement paste, its application on ce-ment industry has been previous mentioned [22] and must beinvestigated since it represents around 20% of the sample weight.

3.4. Density separation

For size fractions above 0.15 mm, the comparative weight per-centage of the sink products from the mineral separation in density

of 2.60 g/cm3 is shown in Fig. 8, while the comparative grades anddistribution of CaO + LOI for these products are shown in Fig. 9.

The results of sand from tertiary crushing compared to CDWshow that the removal of cement paste is improved by VSI commi-nution. As well, an increase in the rotor speed of the impact crusherfrom 55 to 65 m/s reduced the content of porous phase and thusincreased the distribution of the materials in the sink product (den-sity separation of 2.60 g/cm3). However, increasing the speed from65 to 75 m/s did not improve the quality of the product in terms ofenvelop density – not even for the distribution of CaO + LOI.

Moreover, the density distribution in high density productsincreases for the fine fractions, as shown in Fig. 10. Again, thisconfirms that the liberation between cement paste and aggregatesimproves for the fine fractions with a decrease in the porous phasefraction.

3.5. Water absorption and porosity

The comparative porosity and water absorption values for eachstudied sand sample are shown in Fig. 11.

Water absorption obtained from the vacuum system are highercompared to the standards method [21] since the water is forced topenetrate into smaller or less accessible pores, thus these valuesare not comparable to the water absorption values assayed byinternational standards. Apart from that, the comparative resultsare very understandable.

Fig. 10. Weight percentage of high density products for each size fraction.

Fig. 11. Comparative porosity and water absorption.

Fig. 12. Images from SEM (a) backscattered images, (b) com

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The sand produced by VSI crushing clearly demonstrates adecrease in water absorption values (Fig. 11b), thus indicating adecrease in the porous phases. The crushed sand form vertical shaftimpactor presented a reduction in water absorption varying from75% to 58% over different comminution conditions, as comparedto the original sand present in the reference C&D waste. As well,the porosity from the CDW-sand fraction is almost double theporosity of VSI-sand.

In conclusion, the crushing step contributes to the production oflow-porosity recycled sand.

3.6. Scanning electron microscopy

Comparative photomicrographies from SEM-EDS of fractions ofbetween 1.2 and 0.60 mm are presented in Fig. 12. In the backscat-tered image (BSE), the lighter phase is represented by ceramic frag-ments and feldspar, intermediate grey by quartz and the darkergrey by cement paste. In the X-ray composed mapping, quartz isrepresented by the color blue, cement paste by magenta and feld-spar is orange/yellow.

In CDW-sand, cement paste occurs both by bonding smallgrains of quartz (sand), or it is adhered to the particle surface.The sand produced from crushed C&D waste has a high contentof particles made up of the fragmentation of natural aggregates(almost free of binder); the decrease in cement paste attached tothe aggregates surface is also notable.

The aggregates with small grains of quartz (sand) observed inthe remaining CDW-sand are present in VSI-sand, indicatingthat liberation/fragmentation is not properly achieved for this sizefraction.

4. Conclusions

It is important to emphasize that the sand fraction originallypresent in crushed C&D waste represents around 50% of the totalwaste [23]. This fraction is not preferably produced but is gener-ated as a result of breaking C&D materials during demolition, han-

position mapping, and (c) Ca – cement paste mapping.

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dling, transportation and production of coarse recycled aggregates.In addition, the focus on the production of recycled sand as a mainproduct is unusual, but the results shown herein confirm that thisapproach might be interesting in diversifying the recycled productsand thus expanding the recycling market.

The grain size analysis demonstrates that it is possible to pro-duce sand from C&D waste with similar grading of the originalsand fraction present in the total waste. As well, the rock-on-rockcomminution by vertical shaft impact crusher (VSI) improved themorphology of recycled sand when compared to the morphologyof sand from C&D waste.

The content of cement paste can be correlated to the sum of CaOgrade and LOI values. The CDW-sand presents a higher relativeamount of cement paste in fractions above 0.15 mm as comparedto the crushed sand, indicating that comminution concentratesthe cement paste in fractions below 0.15 mm. As well, the crushingstep produces relatively enriched aluminum–silicates sand, mainlydue to the feldspars from concrete coarse aggregates.

The results of the heavy liquid separation, water absorption andporosity clearly demonstrate the difference among the samplesand the reductions in VSI sand porosity.

A comparison among the different crushing conditions indicatesthat rotor speed did not have a crucial influence on the grading ofthe recycled sand or on the shape of the particles. On the otherhand, cement paste content and distribution is influenced bythis parameter. As well, the results of density distribution, waterabsorption and porosity showed that the rotor speed also influ-ences the porosity of particles.

In conclusion, the comminution of C&D waste by vertical shaftimpact crusher made the production of lower porosity recycledsand possible. The change in recycling approach contributes towaste upcycling and encourages the use of recycled sand as a po-tential construction material, as a total or partial replacement ofnatural sand.

Further investigations have been carried out to evaluatethe application of VSI sand in mortars and the fine fraction(<0.15 mm) in the cement industry.

Acknowledgments

The authors gratefully acknowledge the financial support pro-vided by the Brazilian National Council of Technological and Scien-tific Development (CNPq, Process 478142/2009-9 and 550437/2010-0), Fundação de Apoio à Pesquisa no Estado de São Paulo (FA-PESP, Process 2010/15543-1 and 09/54007-0) and the PolytechnicEngineers Association (AEP). The technical support provided bySympatec, Urbem Tecnologia Ambiental and Metso Minerals was

also fundamental for the development of this research, and theauthors recognize its significance.

References

[1] Xing WH, Fraaij A, Pietersen H, Rem P, Van Dijk K. The quality improvement ofstony construction and demolition waste (CDW). J Wuhan Univ Technol MaterSci Ed 2004;19(3):78–85.

[2] Tam VWY, Gao XF, Tam CM, Chan CH. New approach in measuring waterabsorption of recycled aggregates. Constr Build Mater 2008;22(3):364–9.

[3] Meyer C. The greening of the concrete industry. Cem Concr Compos2009;31(8):601–5.

[4] Angulo SC, Ulsen C, John VM, Kahn H, Cincotto MA. Chemical–mineralogicalcharacterization of C&D waste recycled aggregates from Sao Paulo. BrazilWaste Manage 2009;29(2):721–30.

[5] Cachim PB. Mechanical properties of brick aggregate concrete. Constr BuildMater 2009;23(3):1292–7.

[6] Muller A, Stark UL. Crushed sand – waste or valuable product. AufbereitungsTechnik 2005;10:30–43.

[7] Moriconi G, Corinaldesi V, Antonucci R. Environmentally-friendly mortars: away to improve bond between mortar and brick. Mater Struct 2003;36(264):702–8.

[8] Poon CS, Chan D. The use of recycled aggregate in concrete in Hong Kong.Resour Conserv Recycl 2007;50(3):293–305.

[9] Krus M, Hansen KK, Kunzel HM. Porosity and liquid absorption of cementpaste. Mater Struct 1997;30(201):394–8.

[10] Nagataki S, Gokce A, Saeki T, Hisada M. Assessment of recycling processinduced damage sensitivity of recycled concrete aggregates. Cem Concr Res2004;34(6):965–71.

[11] Ahn JW, Kim HS, Han GC. Recovery of aggregate from waste concrete byheating and griding. Geosyst Eng 2001;4(4):123–9.

[12] Shima H, Tateyashiki H, Matsuhashi R, Yoshida Y. An advanced concreterecycling technology and its applicability assessment through input–outputanalysis. J Adv Concr Technol 2005;3(1):53–67.

[13] Kiss L, Schonert K. Liberation of two component material by single particlecompression and impact crushing. Aufbereitungs Technik 1980;5.

[14] Linss E, Mueller A. High-performance sonic impulses – an alternative methodfor processing of concrete. Int J Miner Process 2004;74:S199–208.

[15] Wills BA, Napier-Munn TJ. Wills’ mineral processing technology: anintroduction to the practical aspects of ore treatment. 7th ed. oxford; 2006.

[16] Tomas J, Schreier M, Groger T. Liberation and separation of valuables frombuilding material waste. Rewas’99 global symposium on recycling, wastetreatment and clean technology, vol. I–III; 1999. p. 461–70.

[17] Bengtsson M, Evertsson CM. Measuring characteristics of aggregate materialfrom vertical shaft impact crushers. Miner Eng 2006;19(15):1479–86.

[18] Lindqvist M. Energy considerations in compressive and impact crushing ofrock. Miner Eng 2008;21(9):631–41.

[19] Petersen L, Minkkinen P, Esbensen KH. Representative sampling for reliabledata analysis: theory of Sampling. Chemometr Intell Lab Syst 2005;77(1–2):261–77.

[20] Angulo SC, Ulsen C, Lima FMRS, Chaves AP, John VM. Processing ofconstruction and demolition waste in European recycling plants. PortoAlegre: National Meeting on the use of Construction Waste; 2009.

[21] Daminelli BL. Study of methods for characterization of physical properties ofcoarse recycled aggregates from construction and demolition waste. SãoPaulo: University of Sao Paulo; 2007.

[22] Tomosawa F, Noguchi T, Tamura M. The way concrete recycling should be. JAdv Technol 2005;3(1):3–16.

[23] Ulsen C, Hawlitschek G, Kahn H, Angulo SC, John VM. Technologicalcharacterization of fine fraction from C&D waste. São Paulo: Progress ofRecycling in the Built Environment; 2010.