natgillin/translations-raw huggingface dataset:
Rezultati pokazuju da reciklirani asfalt, u određenom udjelu, može biti prikladna zamjena za prirodni agregat.
The results show that recycled asphalt can be used, in some proportions, as a suitable replacement for natural aggregate.
Ključne riječi: nevezani nosivi sloj, reciklirani asfalt, granulometrijski sastav, fizikalno-mehanička svojstva, nosivost
Key words: unbound base course, recycled asphalt, grading, physicomechanical properties, bearing capacity
Asphalt mixtures are used for construction of pavement wearing courses on more that ninety percent of the road network in Europe [1] and, according to some sources, the situation is quite similar in other parts of the world [2].
Na više od 90 % [1] cestovne mreže u Europi, prema nekim izvorima i u svijetu [2], te na gotovo cjelokupnoj cestovnoj mreži u Hrvatskoj [3] završni su slojevi izrađeni od asfaltnih mješavina.
More than 50 million tons of recycled asphalt are produced each year during the maintenance and rehabilitation of asphalt pavements in Europe [4], and as many as 100 million tons in the USA [5].
Tijekom održavanja i obnove ovih kolnika godišnje se u Europi proizvede više od 50 milijuna [4], a u SAD više od 100 milijuna tona recikliranog asfalta [5].
Recycled asphalt is most often used as a replacement for natural aggregate in mixtures for construction of asphalt pavement courses (wearing, binder and base) and, in this respect, cold or hot recycling procedures are applied, either in-place or inplant.
Reciklirani se asfalt najčešće primjenjuje kao zamjena za prirodni agregat u mješavinama za izradu asfaltnih (habajućih, veznih, nosivih) slojeva kolničkih konstrukcija, pri čemu se primjenjuju postupci hladne ili vruće reciklaže, na gradilištu (in site) ili u postrojenju (in plant).
Considering top limits for allowable proportion of recycled asphalt, and other requirements concerning asphalt mixtures and courses made of such mixtures, there are still considerable quantities of recycled asphalt that can not be reused in this way [6].
S obzirom na gornje granice dopuštenog udjela recikliranog asfalta, kao i druge zahtjeve koji se postavljaju na asfaltne mješavine i od njih izvedene slojeve, još uvijek postoje znatne količine recikliranog asfalta koje se ne mogu iskoristiti na ovaj način [6].
Consequently, alternative solutions have to be found to avoid recycled asphalt disposal costs, i.e. to prevent its illegal dumping.
Stoga je, kako bi se izbjegli troškovi postupanja s recikliranim asfaltom, odnosno spriječilo njegovo ilegalno odlaganje, potrebno pronaći alternativna rješenja.
One of possible alternatives is to use this material as replacement for natural aggregate in unbound base courses.
Jedno je od mogućih upotrijebiti takav materijal kao zamjenu za prirodni agregat u nevezanim nosivim slojevima.
Research on possible use of recycled asphalt in unbound base courses has been in progress since the mid 1990s.
Istraživanja o mogućnosti primjene recikliranog asfalta u nevezanim nosivim slojevima provode se od sredine devedesetih godina prošlog stoljeća.
Although the use of recycled asphalt in unbound base courses is considered inferior when compared to its use in asphalt courses, this method of using recycled asphalt has nevertheless gained in popularity because it is a material recovery technique, and because of its favourable environmental effects (conservation
Iako se primjena recikliranog asfalta u nevezanim nosivim slojevima smatra inferiornom u odnosu na njegovu primjenu u asfaltnim slojevima, budući da se radi o tehnici oporabe materijala, zbog pozitivnih ekoloških učinaka (očuvanje prirodnih resursa, smanjenje količine otpada) kao i ekonomskih ušteda ova metoda upotrebe recikliranog asfalta postaje sve popularnija.
of natural resources, minimisation of waste), and economic benefits.
Međutim, zbog nedostatka sustavnih laboratorijskih i terenskih
However, because of the lack of systemic laboratory and field tests, and due to problems that occur during sporadic use of such mixtures, they have still not been accepted as a standard material for construction of unbound base courses [6, 8- 10].
ispitivanja, kao i problema koji su se javljali prilikom sporadičnih primjena ovakvih mješavina, one još uvijek nisu prihvaćene kao standardni materijal za izradu nevezanih nosivih slojeva [6, 8-10].
The influence of recycled asphalt and natural aggregate type on physical-mechanical properties, compaction parameters, and bearing capacity of mixtures for construction of unbound base courses, is studied in this paper, and the quality of mixture is estimated taking into account requirements specified in General Technical Requirements for Road Works (OTU) [11].
U radu je prikazano istraživanje utjecaja udjela recikliranog asfalta i tipa prirodnog agregata na fizikalno-mehanička svojstva, parametre zbijanja i nosivost mješavina za izradu nevezanih nosivih slojeva, te je dana ocjena kvalitete mješavina s obzirom na zahtjeve navedene u Općim tehničkim uvjetima za radove na cestama (OTU) [11].
2. Experimental analysis
2. Eksperimentalni dio
Testing program, harmonized with the corresponding OTU requirements [11], was conducted in order to estimate possibilities for using the recycled asphalt and natural aggregate mixtures for the construction of unbound base courses.
Da bi se ocijenila mogućnost primjene mješavina recikliranog asfalta i prirodnog agregata za izradu nevezanih nosivih slojeva, proveden je program ispitivanja usklađen sa zahtjevima koji se postavljaju na takve mješavine prema OTU [11].
The testing program was divided into two phases: definition of mixture composition and laboratory testing.
Program ispitivanja podijeljen je u dvije faze, definiranje sastava mješavina i laboratorijska ispitivanja.
Definition of mixture composition
Definiranje sastava mješavina
According to OTU requirements, the use of natural stone aggregate is allowed in the construction of unbound base courses.
Prema OTU, za izradu nevezanih nosivih slojeva dopuštena je upotreba drobljenog i/ili nedrobljenog prirodnog kamenog agregata.
Taking this into account, the research was conducted on recycled asphalt and limestone, as well as on recycled asphalt and gravel mixtures.
Uzimajući to u obzir, istraživanja su provedena na mješavinama recikliranog asfalta i vapnenca kao predstavnika drobljenog te šljunka kao predstavnika nedrobljenog prirodnog agregata.
The following basic materials were used in the preparation of the mixtures:
Za izradu mješavina odabrani su sljedeći osnovni materijali:
- recycled asphalt obtained by mechanical milling (R), (Ceste
- reciklirani asfalt dobiven postupkom strojnog glodanja (R),
Karlovac d.o.o.);
(Ceste Karlovac d.o.o.);
- limestone (V), fractions 0/4, 4/8, 8/16, and 16/32 (Zvečaj
- vapnenac (V), frakcije 0/4, 4/8, 8/16 i 16/32 (kamenolom
Quarry - ARKADA d.o.o.);
Zvečaj - ARKADA d.o.o.);
- gravel (S), fractions 0/4, 4/8, 8/16, and 16/32 (Motičnjak
- šljunak (S), frakcije 0/4, 4/8, 8/16, i 16/32 (šljunčara
Gravel Pit - COLAS Hrvatska d.o.o.);
Motičnjak - COLAS Hrvatska d.d.).
Basic material
Osnovni materijal
Limestone (V)
Vapnenac (V)
Gravel (S)
Šljunak (S)
Recycled asphalt (R)
Reciklirani asfalt (R)
Passing [%]
Ostatak na situ [%]
Particle size distribution results for basic materials
Rezultati ispitivanja granulometrijskog sastava osnovnih materijala
After selection of basic materials, which is the first step in the definition of mixture composition, their particle size distribution (grading) was tested according to HRN EN 933-1 [12] (Table 1).
Nakon odabira osnovnih materijala, što predstavlja prvi korak u postupku definiranja sastava mješavina, provedeno je ispitivanje njihovog granulometrijskog sastav prema normi HRN EN 933-1 [12] (tablica 1.).
Figure 1.
Granulometrijski sastav recikliranog asfalta
Particle size distribution of recycled asphalt
Kako bi se dobile mješavine koje zadovoljavaju postavljene granulometrijske zahtjeve,
It was established during the design procedure that the maximum proportion of recycled asphalt that would be compliant with grading requirements for construction of unbound base courses amounts to 50 % .
Postupkom projektiranja utvrđeno je da maksimalni udio recikliranog asfalta, koji zadovoljava postavljene granulometrijske zahtjeve na mješavine za izradu nevezanog nosivog sloja, iznosi 50 %.
The proportion of recycled asphalt and natural aggregate fractions in the designed mixtures is presented in Table 2.
Udio recikliranog asfalta te frakcija prirodnih agregata u projektiranim mješavinama prikazan je u tablici 2.
Mixtures (shown in Figure 2) were prepared according to the designed composition, and the particle size distribution testing was conducted.
Prema projektiranom sastavu složene su mješavine (slika 2.) na kojima je provedeno ispitivanje granulometrijskog sastava.
Test results for all eight mixtures, and the limit grading values, are shown in Table 3.
Rezultati ispitivanja svih osam mješavina te granično granulometrijsko područje prikazani su u tablici 3.
Mixture label
Oznaka mješavine
V100R0 V80R20 V65R35 V50R50 S100R0 S80R20 S65R35 S50R50 Proportion of basic materials in the mixture [%]
V100R0 V80R20 V65R35 V50R50 S100R0 S80R20 S65R35 S50R50 Udio osnovnih materijala u mješavini [%]
Natural aggregate (V; S)
Prirodni agregat (V; S)
Proportion of recycled asphalt and natural aggregate fraction in designed mixtures
Udio recikliranog asfalta i frakcija prirodnog agregata u projektiranim mješavinama
Recycled asphalt mixed with limestone (left) and gravel (right)
Mješavine recikliranog asfalta i vapnenca (lijevo) te šljunka (desno)
0.02 mm), it can be concluded that, as to their grading, all eight mixtures meet requirements set for materials for the construction of unbound base courses.
Temeljem prikazanih rezultata (granulometrijska krivulja, maksimalna veličina zrna, koeficijent nejednolikosti, udio čestica manjih od 0,02 mm) može se zaključiti da svih osam mješavina u pogledu granulometrijskog sastava zadovoljavaju zahtjeve postavljene na materijale za izradu nevezanih nosivih slojeva.
Laboratory testing of mixtures
Laboratorijska ispitivanja mješavina
The above defined recycled asphalt and natural aggregate mixtures were subjected to laboratory testing in order to determine their physical-mechanical properties, compaction parameters and their bearing capacity.
Na prethodno definiranim mješavinama recikliranog asfalta i prirodnog agregata provedena su laboratorijska ispitivanja fizikalno-mehaničkih svojstava, parametara zbijanja i nosivosti.
All these tests were conducted in accordance with the currently applicable standards.
Sva su navedena ispitivanja provedena u skladu sa sadašnjim normama.
The modified Proctor test based on HRN EN 13286-2 [17] was conducted to determine basic compaction parameters,
Da bi se utvrdili osnovni parametari zbijanja, maksimalna suha prostorna masa i optimalni udio vode, provedeno je ispitivanje
maximum dry density, and optimum water content.
modificiranim Proctorovim pokusom u skladu s normom HRN EN 13286-2 [17].
Because of the maximum grain size, the decision was made to select the compaction method involving a large mould (B), 4.5 kg hammer (B), and 45.7 cm drop height.
S obzirom na maksimalnu veličinu zrna agregata, odabrana je metoda zbijanja u velikom kalupu (B), batom težine 4,5 kg (B) i visinom pada bata 45,7 cm.
The bearing capacity testing, expressed by means of the CBR ratio, was conducted according to HRN EN 13286-47 [18] using samples compacted based on the modified Proctor procedure at optimum water content.
Ispitivanje nosivosti izražene koeficijentom CBR-a provedeno je u skladu s normom HRN EN 13286-47 [18] na uzorcima zbijenim modificiranim Proctorovim postupkom pri optimalnom udjelu vode.
Test results were analysed with regard to the type of natural aggregate and the proportion of recycled asphalt in the mixture.
Analiza rezultata ispitivanja provedena je s obzirom na tip prirodnog agregata i udio recikliranog asfalta u mješavini.
The test results were compared with the OTU requirements for mixtures that are used for construction of unbound base courses [11].
Rezultati ispitivanja uspoređeni su sa zahtjevima koji se postavljaju na mješavine za izradu nevezanog nosivog sloja prema OTU [11].
Physical-mechanical properties
Fizikalno-mehanička svojstva
The suitability of an aggregate for use in unbound base courses is proven by testing its physical-mechanical properties.
Pogodnost agregata za primjenu u nevezanim nosivim slojevima dokazuje se ispitivanjem njegovih fizikalno-mehaničkih
Grading of recycled asphalt and natural aggregate mixtures
Granulometrijski sastav mješavina recikliranog asfalta i prirodnog agregata
Grading properties of recycled asphalt and natural aggregate mixtures
Granulometrijske karakteristike mješavina recikliranog asfalta i prirodnog agregata
OTU request
Otvor sita
Sieve size
[mm]
Proportion of grains smaller than 0.02 mm [%] **
Udio zrna manjih od 0,02 mm [%] **
* 15 to 50 for crushed stone material; 15 to 100 for gravel ** hydrometer analysis for determining the proportion of grains smaller than 0.02 mm was conducted for mixtures V100R0 that had the highest percentage of grains smaller than 0.063 mm, and it was assumed that other limestone and recycled asphalt mixtures have a smaller proportion of grains than the obtained 3.28 %; as in gravel mixtures the proportion of grains smaller than 0.063 mm is smaller than the required 3%, the hydrometer analysis was not conducted for these mixtures
* 15 do 50 za drobljeni kameni materijal; 15 do 100 za šljunak ** postupak aerometriranja kojim se određuje udio zrna manjih od 0,02 mm proveden je za mješavine V100R0 koje su imale najveći postotak zrna manjih od 0,063 mm te je pretpostavljeno da ostale mješavine vapnenca i recikliranog asfalta imaju niži udio zrna od dobivenih 3,28 %; budući da je na mješavinama šljunka udio zrna manjih od 0,063 mm manji od zahtijevanih 3 %, na ovim mješavinama nije proveden postupak aerometriranja
Shape of coarse aggregate - proportion of unfavourably shaped grains
Oblik zrna-udio zrna nepovoljnog oblika
According to OTU, the proportion of unfavourably shaped grains (3:1) must not exceed 40 %.
Prema OTU, udio zrna nepovoljnog oblika (3:1) ne smije biti veći od 40 %.
Test results have revealed that the proportion of unfavourably shaped grains ranges from 4.9 to 14.7 % in recycled asphalt and limestone mixtures, and from 9.8 to 17.2 % in recycled asphalt and gravel mixtures.
Provedenim je ispitivanjima dobiveno da udio zrna nepovoljnog oblika iznosi od 4,9 do 14,7 % na mješavinama recikliranog asfalta i vapnenca te od 9,8 do 17,2 % na mješavinama recikliranog asfalta i šljunka.
The influence of the proportion of recycled asphalt on the proportion of unfavourably shaped grains is presented in Figure 3.
Utjecaj udjela recikliranog asfalta na udio zrna nepovoljnog oblika prikazan je na slici 3.
Considering the type of natural aggregate, it can be seen that gravel mixtures have a greater content of unfavourably shaped grains compared to mixtures with limestone.
S obzirom na tip prirodnog agregata vidljivo je da mješavine sa šljunkom imaju veći udio zrna nepovoljnog oblika u odnosu na mješavine s vapnencem.
The proportion of unfavourably shaped grains increases with an increase in the proportion of recycled asphalt, which is more pronounced in mixtures with limestone compared to mixtures with gravel.
Povećanjem udjela recikliranog asfalta povećava se i udio zrna nepovoljnog oblika, što je izraženiji na mješavinama s vapnencem u odnosu na mješavine sa šljunkom.
Such trend is due to great difference in the proportion of unfavourable shaped grains between recycled asphalt and limestone, while these differences between the gravel and recycled asphalt are only pronounced in fraction 16/32.
Takav trend posljedica je velikih razlika u udjelu zrna nepovoljnog oblika između recikliranog asfalta i vapnenca, dok su te razlike između šljunka i recikliranog asfalta izražene samo na frakciji 16/32.
By increasing the proportion of recycled asphalt from 0 % to 20, 35 and 50 % , the proportion of unfavourably shaped grains increases by 79, 140, and 200 % for mixtures with limestone, i.e. by 31, 53, and 76 % for mixtures with gravel.
Povećanjem udjela recikliranog asfalta s 0 % na 20, 35 i 50 %, udio zrna nepovoljnog oblika se povećao 79, 140 i 200 % za mješavine s vapnencem, odnosno 31, 53 i 76 % za mješavine sa šljunkom.
Proportion of unfavourably shaped grains as related to recycled asphalt content
Udio zrna nepovoljnog oblika u ovisnosti o udjelu recikliranog asfalta
Despite the negative influence of the proportion of recycled asphalt on the proportion of unfavourably shaped grains, this influence is below the allowed maximum of 40 % in case of all mixtures.
Unatoč negativnom utjecaju udjela recikliranog asfalta na udio zrna nepovoljnog oblika, on je na svim mješavinama manji od maksimalno dopuštenih 40 %.
Water absorption
Upijanje vode
According to OTU, the maximum percentage of water absorption is 1.6 % for granular stone materials used in the production of unbound base courses.
Maksimalni postotak upijanja vode zrnatog kamenog materijala za izradu nevezanih nosivih slojeva prema OTU iznosi 1,6 %.
The testing has revealed that the water absorption varies from 0.4 to 0.8 % for the recycled asphalt and
Provedenim je ispitivanjima dobiveno da upijanje vode iznosi od 0,4 do 0,8 % na mješavinama recikliranog asfalta i vapnenca
limestone mixtures, and from 0.8 to 1 % for the recycled asphalt and gravel mixtures.
te od 0,8 do 1 % na mješavinama recikliranog asfalta i šljunka.
The influence of the proportion of recycled asphalt on water absorption is presented in Figure 4.
Utjecaj udjela recikliranog asfalta na upijanje vode prikazan je na slici 4.
Considering the type of natural aggregate, it can be seen that gravel mixtures have a greater water absorption capability compared to mixtures with limestone.
S obzirom na tip prirodnog agregata vidljivo je da mješavine sa šljunkom imaju veću sposobnost upijanja vode od onih s vapnencem.
Water absorption increases with an increase in the proportion of recycled asphalt in the mixtures, and the influence of recycled asphalt on the affinity of mixtures toward water absorption is more pronounced in mixtures with limestone compared to mixtures with gravel.
Povećanjem udjela recikliranog asfalta u mješavinama povećava se i postotak upijanja vode, samo što je utjecaj recikliranog asfalta na sklonost mješavina prema upijanju vode izraženiji na mješavinama s vapnencem u odnosu na one sa šljunkom.
By increasing the proportion of recycled asphalt from 0 % to 20, 35 and 50 % in mixtures with limestone, the water absorption increases by 25, 75, and 100 %.
Na mješavinama s vapnencem povećanjem udjela recikliranog asfaltna s 0 % na 20, 35 i 50 % upijanje vode se povećalo 25, 75 i 100 %.
In case of mixtures with gravel, the change in the proportion of recycled asphalt from 0 % to 20 and 35 % results in the 12.5 % increase in water absorption, while this increase amounts to 25 % when the proportion is changed from 0 % to 50 %.
Promjena udjela recikliranog asfalta s 0 % na 20 i 35 % na mješavinama sa šljunkom rezultirala je povećanjem upijanja vode za 12,5 % te povećanjem od 25 % promjenom udjela s 0 % na 50 %.
Water absorption as related to recycled asphalt content
Upijanje vode u ovisnosti o udjelu recikliranog asfalta
Because of hydrophobic properties of bitumen, it may be expected that the recycled asphalt will exhibit a lower water absorption capability compared to natural aggregate.
Zbog hidrofobnih svojstava bitumena očekivalo bi se da reciklirani asfalt ima manju sposobnost upijanja vode od prirodnog agregata.
In all mixtures tested, water absorption was lower than the maximum allowed 1.6 % .
Upijanje vode je na svim ispitanim mješavinama manje od maksimalno dopuštenih 1,6 %.
Loose grains content
Trošna, nekvalitetna zrna
According to OTU, the proportion of loose grains in the mixtures for construction of unbound base courses should not exceed 7 %.
Udio trošnih, nekvalitetnih zrna u mješavinama za izradu nevezanih nosivih slojeva, prema OTU, ne smije biti veći od 7 %.
The proportion of loose grains increased with an increase in the proportion of recycled asphalt in the mixture.
Udio trošnih zrna u mješavinama s 20 % recikliranog asfalta bio je 3,9 %.
The proportion of loose grains in the mixtures with 20 % of recycled asphalt amounted to 3.9 %.
Daljnjim povećanjem udjela recikliranog asfalta na 35 % i 50 %, udio trošnih zrna prosječno se povećao za 72 % odnosno 146 %.
By further increasing the proportion of recycled asphalt to 35 % and 50 % , the proportion of loose grains increases on an average by 72 % and 146 %, respectively.
Postavljeni kriterij maksimalnog udjela trošnih zrna od 7 % nisu zadovoljile mješavine koje sadrže 50 % recikliranog asfalta.
Proportion of loose grains as related to recycled asphalt content
Udio trošnih, nekvalitetnih zrna u ovisnosti o udjelu recikliranog asfalta
Resistance to abrasion according to Los Angeles method
Otpornost prema drobljenju i habanju po metodi Los Angeles
According to OTU, the maximum Los Angeles abrasion value is 45 % for aggregates that are used for construction of unbound base courses.
Maksimalna vrijednost koeficijenta Los Angeles agregata koji se koristi za izradu nevezanih nosivih slojeva prema OTU iznosi 45 %.
Test results show that the LA values range from 19.6 to 19.7 % for mixtures with limestone, and from 22.5 to 25.2 % for mixtures with gravel.
Provedenim je ispitivanjima dobiveno da su vrijednosti koeficijenta LA od 19,6 do 19,7 % na mješavinama s vapnencem, odnosno od 22,5 do 25,2 % na mješavinama sa šljunkom.
The influence of the recycled asphalt content on the LA value is shown in Figure 6.
Utjecaj udjela recikliranog asfalta na vrijednost koeficijenta LA prikazan je na slici 6.
LA value as related to recycled asphalt content
Vrijednost koeficijenta LA u ovisnosti o udjelu recikliranog asfalta
Considering the type of natural aggregate, it can be seen that Los Angeles values are higher in gravel mixtures compared to mixtures with limestone.
S obzirom na tip prirodnog agregata, vidljivo je da su vrijednosti koeficijenta Los Angeles veće na mješavinama sa šljunkom u odnosu na one s vapnencem.
The proportion of recycled asphalt does not greatly influence the change in LA value for limestone mixes, which could have been expected as the aggregate used in the preparation of asphalt mixture is of limestone origin, and comes from the same source as the limestone used in the research.
Udio recikliranog asfalta nije znatno utjecao na promjenu vrijednosti koeficijenta Los Angeles na mješavinama s vapnencem, što je i očekivano budući da je agregat korišten pri izradi asfaltne mješavine vapnenačkog podrijetla te iz istog izvora kao vapnenac korišten u istraživanju.
Considering resistance to abrasion expressed by the LA value, it can be concluded that the properties of recycled asphalt are similar to that of limestone.
S obzirom na otpornost prema drobljenju izraženu koeficijentom LA, može se zaključiti da reciklirani asfalt ima svojstva slična vapnencu.
These results are in harmony with the results obtained by Locander [19] and Mokwa
Takvi rezultati u skladu su s prijašnjim istraživanjima Locandera [19] te Mokwa i Peeblesa [20].
and Peebles [20].
Na mješavinama sa šljunkom dolazi do
In case of mixtures with gravel, the LA value decreases with an increase in recycled asphalt content in the mixture.
smanjenja vrijednosti koeficijenta Los Angeles s povećanjem udjela recikliranog asfalta u mješavinama.
By increasing the proportion of recycled asphalt from 0 % to 20, 35 and 50 %, the LA values decrease by 4, 8 and 11 %, respectively.
Povećanjem udjela recikliranog asfalta s 0 % na 20, 35 i 50 %, vrijednosti koeficijenta Los Angeles su smanjene za 4, 8 i 11 %.
In all mixtures, the Los Angeles value was lower than the maximum allowed value of 45 %.
Vrijednost koeficijenta Los Angeles na svim je ispitanim mješavinama manja od maksimalno dopuštenih 45 %.