HIGHLY MODIFIED BINDERS ORBITON HiMA

Transcription

1 HIGHLY MODIFIED BINDERS HiMA Application Guide Version 2015/1e

2 HIGHLY MODIFIED BINDERS HiMA Authors: Krzysztof Błażejowski (PhD Civ.Eng) Jacek Olszacki (PhD Civ.Eng.) Hubert Peciakowski (M.Sc. Chem. Eng.) Copyright by ORLEN Asfalt sp. z o.o. ul. Chemików Płock Both the Authors and ORLEN Asfalt Sp. z o.o. have exercised due diligence to ensure that the information contained herein is accurate and reliable. However, they shall not be liable for any consequences of the use of information contained in this document, in particular for a loss of any type and form. The reader shall be solely responsible for the use of these data. 2

3 HIGHLY MODIFIED BINDERS HiMA CONTENT Introduction Principle of HiMA HiMA product family Purpose of HiMA HiMA test results Properties as per EN (Polish National Annex NA 2014) Low-temperature properties testing Superpave PG system Asphalt mixture cracking resistance tests, TSRST method Testing of properties at intermediate temperatures - fatigue resistance Superpave PG system Asphalt mixture fatigue, 4PB-PR test Testing of properties at high temperatures Classical method with DSR (G* and ) MSCR test Rutting resistance of asphalt mixtures Additional tests Experimental sections in Poland Technological guidelines Viscosity dependence on temperature Process temperatures Binder samples at the lab HiMA binder storage Asphalt mixture production Asphalt mixture transport Placement Acceptance tests CLOSURE LITERATURE

4 HIGHLY MODIFIED BINDERS HiMA INTRODUCTION Research conducted by numerous academic centres over recent decades has corroborated the claim that higher polymer content in binder produces additional quality benefits, substantially contributing to the durability improvement of asphalt pavements in terms of cracking resistance, rutting and fatigue. Particularly encouraging was exceeding the limit of SBS polymer content (about % m/m), after which the polymer phase in the polymer-modified binder becomes continuous. However, such a significant quantity of SBS for binder modification carried with it specific technical consequences for the production and application of modified binder, connected with following aspects: stability problems during the storage and transport of modified binder (high risk of polymer separation from the product), very high viscosity of polymer modified binder, which means that such binders would have to be heated in the mixing plant to a much higher temperature than conventional modified binders with lower polymer quantity and there are significant problems with compaction of the asphalt mixture containing highly viscous binders at the road construction site - rapid stiffening of the mixture occurred and low compaction ratios were achieved. The above limitations to the concept of highly modified binder for road engineering uses represented a challenge not only for road binder manufacturers, but also for polymer suppliers. However, research work conducted by the polymer industry has produced positive outcomes, resulting in the market availability, for the past few years, of a polymer which enables the production of highly-modified binder without the limitations referred to above. Binders of this type are referred to as HiMA - Highly Modified Asphalt. Research and implementation work on new highly modified binders with a new type of polymer have shown that they are products above standard functional properties, characterised by, inter alia, very good resistance to rutting, water and frost and excellent fatigue strength and cracking resistance [Timm et al. 2012, 2013; Kluttz et al. 2013; Willis et al. 2012; Scarpas et al. 2012]. In terms of structure, courses with HiMA are stiffer than those with conventional modified binders while maintaining high tolerance to increasing tensile strains (so-called fatigue strains) [Kluttz et al. 2009; West et al. thus potentially allowing a reduction in the thickness of the set of asphalt courses. Full-scale testing conducted since 2009 on the experimental track in the US (NCAT Pavement Test Track) showed that the experiment based on reducing pavement thickness by 18% and simultaneous use of a highly modified, special HiMA binder was a success the surface proved to be resistant to rutting and fatigue cracking [West et al. 2012]. 4

5 HIGHLY MODIFIED BINDERS HiMA 1 PRINCIPLE OF HiMA As already mentioned, the primary purpose behind highly-modified binders is to counteract pavement cracking and plastic deformations (ruts), and to increase the fatigue resistance of asphalt courses. To achieve that, high polymer content in excess of 7% m/m is used, which leads to phase reversal in the mixture of binder with the polymer (Figure 1.1). SBS polymer Binder HiMA (continuous polymer matrix) SBS polymer Binder Conventional modified binder (continuous binder matrix) Figure 1.1. Volumetric proportions between binder and polymer in conventional polymer-modified binder and highly-modified binder The advantages of a continuous polymer network (polymer phase), acting in the binder and bituminous mix as an elastic reinforcement, can be clearly demonstrated taking the example of limiting crack propagation in asphalt mixture courses by highly-modified binders. Figure 1.2 shows schematic representations of two hypothetical cases: Figure A: propagation of cracks through the asphalt mixture course with a conventional modified binder with non-continuous polymer network (marked with dispersed yellow dots) - here, the crack can pass through the binder course, finding weak spots between the polymer network sections, Figure B: propagation of cracks through the asphalt mixture course with highly-modified binder with a continuous polymer network (marked with yellow lines) here, the passage of the crack through the binder course is difficult because of the barrier formed by the polymer network. 5

6 HIGHLY MODIFIED BINDERS HiMA Magnification of Detail 1 Magnification of Detail 2 Detail 1 Detail 2 Wearing course with typical PMB Binder course Wearing course with PMB HiMA Binder course Crack propagation "upwards" from the binder course Figure 1.2. Crack propagation through asphalt courses, a) with typical polymer-modified binder, b) with highly-modified binder 2 HiMA PRODUCT FAMILY Since 2011, the Technology, Research and Development Department of ORLEN Asfalt has been working to develop a new family of polymer modified bituminous binders. Three new highly-modified binders have been developed as a result of laboratory work and production tests. These are: 25/55-80 HiMA 45/80-80 HiMA 65/ HiMA All HiMA types are classified according to the European Standard of PN-EN Figure 2.1. presents a Pen25-SP R&B (Penetration at 25 C vs Softening Point Ring&Ball) chart showing how the new products are positioned relative to the paving-grade binders and (conventional) modified binders which have been used to date in Poland. A significant increase in the SP R&B softening point range for all types of HiMA products can be clearly seen, which is a direct result of their high polymer content. 6

7 Softening Point TR&B[ C] HIGHLY MODIFIED BINDERS HiMA Legend: paving-grade binder as per PN-EN 12591:2010. typical modified binder as per PN-EN 14023:2011. highly-modified binder HiMA Penetration at 25 C [0.1 mm] Figure 2.1. Positioning of HiMA relative to paving-grade binders and conventional polymer modified binders in the Pen25-SP R&B chart 3 PURPOSE OF HiMA HiMA can be used in technologies and locations for which the required durability is very high. 25/55-80 HiMA is intended for a typical asphalt base courses and asphalt base courses of long-life pavements (type: perpetual pavements ), high AC WMS modulus mixtures (EME/HMB) and places with slow traffic. 45/80-80 HiMA is intended for wearing courses and binder courses of pavements exposed to very heavy loads and working at low temperatures, as well as for other courses in specific places, e.g. on bridges, 65/ HiMA is intended for special technologies, e.g. SAMI courses, for the production of asphalt emulsions used in slurry seal; because of its high penetration, it has limited use for hot-mix bituminous mixtures. 4 HiMA TEST RESULTS Highly-modified asphalts from the HiMA family have been tested in the course of laboratory works, process tests and road trial sections. Below are the test results of binders and asphalt mixtures containing those binders compared with other road binders manufactured by ORLEN Asfalt. 7

8 HIGHLY MODIFIED BINDERS HiMA 4.1. Properties as per EN (Polish National Annex NA 2014) Table 4.1. shows the required properties and the control test results of HiMA in reference to the National Annex, Table NA.2. of PN-EN 14023:2011. Table 4.1 The properties of HiMA as per PN-EN 14023:2011/Ap1:2014 (National Annex NA 2014) Property Test method Unit 25/55-80 HiMA NA requirement Test result 45/80-80 HiMA NA requirement Test result 65/ HiMA NA requirement Test result Penetration at 25 C EN mm, from 25 to from 45 to from 65 to Softening point EN 1427 C Cohesion Force ductility by ductilometer method (tension of 50 mm/min) EN EN J/cm 2 TBR (at 15 C) 5.5 TBR (at 10 C) 3.7 TBR (at 10 C) 3.5 Change in mass % Ageing resistance Retained penetration EN % Softening point increase C Flash point EN ISO 2592 C Breaking point EN C Elastic recovery at 25 C EN % at 10 C EN % TBR 71 TBR 76 TBR 85 Softening point drop after testing as per EN Elastic recovery at 25 C after testing as per EN Elastic recovery at 10 C after testing as per EN EN 1427 C TBR 0.0 TBR -1.0 TBR 0.0 EN % EN % TBR 69 TBR 70 TBR 80 Storage stability (3 days) Softening point difference TBR To Be Reported EN EN 1427 C <5 1.0 <5 0.0 < Low-temperature properties testing Superpave PG system In the Performance Grade system, the Bending Beam Rheometer (BBR) is used to test binder behaviour at low temperatures. 8

9 Temperature [ C] HIGHLY MODIFIED BINDERS HiMA In BBR, the degree of binder stiffness at a low temperature is being evaluated. It was assumed that creep stiffness S(t) may not exceed 300 MPa, which should ensure the appropriate cracking resistance (no binder over-stiffness). The value of the m parameter should in turn be greater than 0.300, which is related to the relaxation of stresses present in the binder when the temperature drops. Table 4.2 presents low-temperature property testing results, with the test carried out by the Bending Beam Rheometer, and the samples aged in RTFOT and PAV. Test parameters: Testing at four temperatures: -10, -16, -22, -28 C. Sample temperature control time: 60 min. Values recorded after 60 s of loading: S(60s) MPa, m(60s) Table 4.2. Low-temperature property testing results for HiMA after ageing (RTFOT+PAV), by the Bending Beam Rheometer at S(60) = 300 MPa, m(60) = 0.3 and stiffness S at -16 C) Binder type Critical temperature at S(60) = 300 MPa T(S)60 [ C] Critical temperature at m(60) = 0.3 T(m)60 [ C] Binder stiffness at -16 C S(T)-16 [MPa] EN 14771, AASHTO PP 42 25/55-80 HiMA /80-80 HiMA / HiMA Figure 4.1. shows a comparison of low-temperature properties for HiMA with conventional modified binders and paving-grade binders with a similar penetration range. (left bar) S(60) = 300 MPa (right bar) m(60) = 0.3 Figure 4.1. Comparison of low-temperature properties for HiMA (critical temperature at S(60) = 300 MPa and at m(60) = 0.3) with conventional polymer modified binders and paving-grade binders with a similar penetration range. 9

10 HIGHLY MODIFIED BINDERS HiMA Asphalt mixture cracking resistance tests, TSRST method Next to the testing of HiMA binders, tests have also been conducted on asphalt mixtures containing those binders. Asphalt concrete AC 16 S with the same grain size and varying binder types (for comparison) was used for the tests (comparative mixture). The results of the TSRST (Thermal Stress Restrained Specimen Test) as per EN is shown in Figure 4.2. The presented results show a conventional failure point defined in the TSRST testing conditions, at a temperature drop gradient -10 K/h, on a rectangular beam of AC16S mixture. It should be noted that HiMA perform better in comparison with other binders having a similar penetration range. Failure point Tfailure[ C] Figure 4.2. Pavement cracking resistance test results, TSRST method as per EN Testing of properties at intermediate temperatures - fatigue resistance Superpave PG system The DSR (Dynamic Shear Rheometer) is used for the binder fatigue test. The test of binder resistance to fatigue cracks is conducted at an intermediate temperature (depending on the PG type). The requirements limit the stiffness G* sinδ to a maximum value of kpa (the newer version of the PG system raises this requirement to kpa). Table 4.3. shows the results of DSR tests to determine the conventional critical temperature depending on fatigue cracking and Figure 4.2. shows a comparison with other binders having a similar hardness. 10

11 Fatigue critical temperature [ C] HIGHLY MODIFIED BINDERS HiMA Table 4.3. DSR test results for the properties of HiMA binders. Binder type Critical temperature at G* sinδ = kpa Critical temperature at G* sinδ=6 000 kpa binder after RTFOT+PAV [ C] binder after RTFOT+PAV [ C] AASHTO T 315 AASHTO T /55-80 HiMA /80-80 HiMA / HiMA Figure 4.3. Comparison of fatigue properties in the DSR (G* sinδ=5 000 kpa) using the Superpave method (the lower temperature the better result) Asphalt mixture fatigue, 4PB-PR test In consideration of the working method of an internal polymer network in HiMA, those binders are characterized by a very high fatigue resistance. Tests performed at the laboratory of the Gdansk University of Technology were conducted using the four-point bending scheme (4PB-PR), with rectangular beams, as per PN-EN for a reference AC16W mix (for 25/55-80 HiMA: Binder=4.6 % m/m, Vm=4.9 % v/v, VMA=15.7 % v/v, VFB = 69.2 %; for 45/80-80 HiMA: Binder=4.6 % m/m, Vm=4.1 % v/v, VMA=15.1 % v/v, VFB=72.7 %; the same aggregate mix in both cases). The tests showed that the fatigue resistance of HiMA AC16W mix is extremely high and, in particular, that it is possible to safely resist the course deformations which are much more severe than the typical ones without downgrading the pavement performance. This confirms the results achieved in the US on the NCAT Pavement Test Track. 11

12 HIGHLY MODIFIED BINDERS HiMA Figure 4.4. shows the fatigue curves for AC16W mixes of 25/55-80 HiMA and 45/80-80 HiMA. Nf 50=1E+11e ε R 2 =0.94 Deformation [ ] Nf 50=3E+11e ε R 2 =0.98 Fatigue performance N f50 [cycles] Figure 4.4. Fatigue curves for AC16W mix with highly-modified 25/55-80 HiMA (red line) and 45/80-80 HiMA (green line) binders in 4PB-PR test, temperature 10 C, frequency 10 Hz Deformation required to achieve 10 6 cycles for tested AC16W mixtures.: AC16W with 25/55-80 HiMA 430 AC16W with 45/80-80 HiMA 381 In summary, it can be said that in the case of typical road pavement, in which the deformations in the asphalt base course are usually within the range of µε, the use of an HiMA binder will change this pavement into a perpetual type, which has a fatigue durability of up to 50 years. If HiMA is used additionally in AC WMS high stiffness asphalt concrete, the period of durability is theoretically even longer Testing of properties at high temperatures Classical method with DSR (G* and ) According to the classical Superpave method (currently withdrawn from the specification), the resistance of the binder to high temperatures is determined in the DSR by measuring two parameters: complex stiffness modulus G* and angle phase of the binder prior to RTFOT, complex stiffness modulus G* and angle phase of the binder after RTFOT. It is required that binder demonstrates specific parameters tested in the DSR at its expected maximum pavement service temperature (so-called high PG): G*/sin > 1.00 kpa for binder before RTFOT, 12

13 Critical temperature [ C] HIGHLY MODIFIED BINDERS HiMA G*/sin > 2.20 kpa for binder after RTFOT. Table 4.4 presents the DSR test results for the relevant properties. Test parameters: complex stiffness modulus G* and angle phase of the binder prior to RTFOT to determine critical temperature at G*/sin =1 kpa, complex stiffness modulus G* and angle phase of the binder after RTFOT to determine critical temperature at G*/sin =2.2 kpa, Table 4.4. DSR test results for the properties of binders. Binder type Critical temperature at G*/sin =1 kpa binder prior to RTFOT [ C] AASHTO T315 Critical temperature at G*/sin =2.2 kpa binder after RTFOT [ C] AASHTO T315 25/55-80 HiMA /80-80 HiMA / HiMA Figure 4.5. presents a comparison of upper critical temperature in the DSR test taking into account two parameters (G*/sinδ) for HiMA and comparable binders. (left bar) at G*/sin = 1 kpa (right bar) at G*/sin = 2.2 kpa Figure 4.5. Comparison of upper critical temperature in the DSR test for HiMA with conventional modified binders and paving-grade binders with a similar penetration range. 13

14 Complex stiffness modulus G* [kpa] Complex stiffness modulus G* [kpa] HIGHLY MODIFIED BINDERS HiMA Figures 4.6. to 4.8. present Black curves for paving-grade binders and polymer modified binders with penetration ranges similar to that of HiMA. A Black curve is used to evaluate the dependence of the binder's complex stiffness modulus G* on angle phase. As shown in the drawings, at the small and large values of the complex stiffness modulus G* they are correlated with the elastic constituent of the binder. Legend: Phase angle [ ] Figure 4.6. Comparison of Black curves for 25/55-80 HiMA with 25/55-60, 10/40-65 and paving-grade binder 35/50 (all non-aged binders). Legend: Phase angle [ ] Figure 4.7. Comparison of Black curves for 45/80-80 HiMA with 45/80-55, 45/80-65 binders and paving-grade binder 50/70 (all non-aged binders). 14

15 Complex stiffness modulus G* [kpa] Complex stiffness modulus G* [kpa] HIGHLY MODIFIED BINDERS HiMA Legend: Phase angle [ ] Figure 4.8. Comparison of Black curves for 65/ HiMA with 65/ binders and paving-grade binder 70/100 (all non-aged binders). Figures present master curves of the complex stiffness modulus G* and angle phase 8 depending on frequency. The test was conducted in the frequency range of Hz at -10, 0, 10, 25, 40, 60, 70 C, and then, using the temperature and frequency superposition, master curves for 25 C were obtained. Legend: Frequency Figure 4.9. Master curve of the complex stiffness modulus G* depending on the frequency for HiMA binders before ageing. Sweep in the frequency range from 0.1 to 10 Hz, superposition to 25 C 15

16 Phase angle [ ] HIGHLY MODIFIED BINDERS HiMA Legend: Frequency Figure Master curve of the angle phase 8 depending on the frequency for HiMA binders before ageing. Sweep in the frequency range from 0.1 to 10 Hz, superposition to 25 C MSCR test In the original PG system, the results of critical temperature tests with parameter G*/sin 1 kpa for binders before ageing and G*/sin 2.2 kpa for binders after RTFOT indicate binder resistance to permanent deformation (and basically binder share in the resistance of a asphalt mixture to deformation). Currently, however, this relationship has been challenged and the PG system was adjusted based on the newly introduced MSCR test, which has gradually come into use in the US since The MSCR ( Multiple Stress Creep Recovery test) involves the measurement of certain binder properties in order to determine (inter alia) the resistance of a asphalt mixture with the binder to permanent deformation (rutting). The MSCR test is conducted according to the following standards: AASHTO TP 70 Standard Method of Test for Multiple Stress Creep Recovery (MSCR) Test of Asphalt Binder Using a Dynamic Shear Rheometer (DSR) and ASTM D7405 Standard Test Method for Multiple Stress Creep and Recovery (MSCR) of Asphalt Binder Using a Dynamic Shear Rheometer. The MSCR test is intended to replace additional tests of modified binders specified in the so-called PG plus : elastic recovery, force ductility, toughness and tenacity. The following mechanisms are examined in the course of the MSCR: binder sample creep mechanism during the 1-second stress application, binder sample recovery mechanism during the 9-second relieving cycle (after the stress is removed). 16

17 Recovery MSCR [%] HIGHLY MODIFIED BINDERS HiMA The test has been conducted for two stress values: 0.1 kpa and 3.2 kpa, and at the upper temperature limit at which the pavement with the tested binder is to operate. The planning assumed that maximum pavement temperatures in Poland would not exceed C, and therefore all binders were tested at 64 C and additionally at 70 C in order to examine how the behaviour of the HiMA binder changes with extreme changes in temperature. The temperatures of 64 C and 70 C are compatible with the PG system used in the US. In effect, two pairs of results are obtained: non-recoverable creep compliance J nr [kpa 1 ] and the average percentage deformation R [%] for two stress values (0.1 kpa and 3.2 kpa). Of those parameters, Jnr3.2 kpa is crucial for binder classification, as it is the measure of binder resistance to deformation the smaller Jnr3.2 kpa, the greater the rutting resistance. R 3.2 recovery, in turn, indicates the effectiveness of binder modification and is in some sense a measure of its elasticity (if modified binder is tested). Two additional indicators are calculated from the results of J nr0.1 kpa, J nr3.2 kpa, R 01 and R 32: J nr,diff - a percentage indicator of the difference in J nr after the change (increase) in the stress from 0.1 to 3.2 kpa this is a measure of binder sensitivity to load increase; the increase Jnr must not be greater than 75 %, R diff - percentage indicator of the difference in elastic recovery after the change (increase) in the stress from 0.1 to 3.2 kpa this is a measure of binder elasticity under load increase conditions. The American tests [Anderson, 2011] have determined experimentally the line separating modified binders from non-modified ones or, in other words effectively modified binders from non-modified binders. That line is presented in Figures 4.11 and Figure 4.11 presents test results for various binders manufactured by ORLEN Asfalt and tested by MSCR at 64 C, and Figure 4.12 presents test results obtained at 70 C. Figures also present the line separating modified binders (i.e. binders which meet the requirements for modified binders in terms of recovery R 3.2 correlated with J nr3.2 kpa range). In both cases, the charts refer to the stress 3.2 kpa. Legend: Neat binders Recovery MSCR = *(Jnr at Pa) Modified binders Non-modified binders J nr at Pa [kpa -1 ] Figure Presentation of binder results on the MSCR chart: elastic deformation R as a function of Jnr at a load of 3.2 kpa at 64 C 17

18 Recovery MSCR [%] HIGHLY MODIFIED BINDERS HiMA Legend: Neat binders Recovery MSCR = *(Jnr at Pa) Modified binders Non-modified binders J nr at Pa [kpa -1 ] Figure A presentation of binder results on the MSCR chart: elastic deformation R as a function of Jnr at a load of 3.2 kpa at 70 C Table 4.4 presents a summary of the results of HiMA binders in the MSCR test. Table 4.4 MSCR test results for HiMA binders at 64 C and 70 C (binders after RTFOT) Property as per ASTM D /55-80 HiMA 45/80-80 HiMA 65/ HiMA at 64 C at 70 C at 64 C at 70 C at 64 C at 70 C Recovery [%] R R Rdiff Jnr [kpa-1] Jnr Jnr Jnr,diff Classification and traffic designation (classification according to AASHTO MP 19) Real PG PG (Superpave) Traffic designation as per Jnr3.2 result E (extremely heavy) E (extremely heavy) E (extremely heavy) 18

19 Rut growth rate WTSAIR [mm/1 000] HIGHLY MODIFIED BINDERS HiMA Rutting resistance of asphalt mixtures In a similar manner as cracking resistance tests at low-temperature, the high-temperature properties of asphalt mixtures rutting resistance have also been tested. The same asphalt mixture was used for the tests (AC 16 S) conducted as per PN-EN in a small apparatus (method B), sample in the air, at 60 C, with loading cycles. The results are shown in Figure Figure Results of pavement rutting resistance test, parameter WTS AIR, method EN , small wheel tracker (method B), sample in the air, at 60 C, with loading cycles Additional tests The results of other additional tests are shown in Table 4.5. Table 4.5. Results of additional tests Property Test method Unit 25/55-80 HiMA 45/80-80 HiMA Test result 65/ HiMA Fraass Breaking point after RTFOT EN C Softening point increase/drop after RTFOT Softening point increase/drop after RTFOT+PAV Storage stability (7 days). Softening point difference EN EN 1427 EN EN EN 1427 EN EN 1427 C C C

20 HIGHLY MODIFIED BINDERS HiMA Table 4.5. Results of additional tests cont d. Property Test method Unit 25/55-80 HiMA Viscosity (to determine temperatures for pumping, aggregate mixing and bituminous mixtures compaction): Dynamic viscosity at 90 C (Brookfield spindle no. 18) Dynamic viscosity at 135 C (Brookfield spindle no. 18) Dynamic viscosity at 160 C (Brookfield spindle no. 18) Dynamic viscosity at 200 C (Brookfield spindle no. 18) Dynamic viscosity at 135 C after RTFOT (Brookfield spindle no. 18) Dynamic viscosity at 160 C after RTFOT (Brookfield spindle no. 18) 45/80-80 HiMA Test result 65/ HiMA ASTM D Pa.s no data ASTM D Pa.s ASTM D Pa.s ASTM D Pa.s EN ASTM D EN ASTM D Pa.s Pa.s Dynamic viscosity has not been tested by Brookfield method at 60 C (and at 90 C for 25/55-80 HiMA) as the measured temperature is lower than the softening temperature of the binder using the Ring and Ball method. 5 EXPERIMENTAL SECTIONS IN POLAND In October 2013, the first experimental section of road pavement with 65/ HiMA was completed in Poland. This was the 6 th section constructed with HiMA in Europe and the first in Poland. The section was located on a road managed by the Road Administration in Katowice (Silesian Voivodeship DoT). Two wearing course sections were placed, one made of AC 11 (layer thickness of 4 cm), and the other of a special SMA 5 DSH mix (so-called silent pavement, 2 cm thick layer). The trial sections provided a lot of process data and proved that the properties of production at the mixing plant and compaction on the road of asphalt mixtures with highly-modified, HiMA-type binder are similar to those demonstrated by conventional SBS-modified binder types. It was also established that 65/ HiMA, which was used in mixtures on the sections, due to its high penetration (softness) should be used in special technologies and the production of cold mixes, rather than for hot-mix asphalts. During subsequent phases of production, transport and placement of HiMA binders in mixtures, the employees of ORLEN Asfalt checked the thermal conditions using a thermal imaging camera. The results of these checks are presented on Figures 5.1 to

21 HIGHLY MODIFIED BINDERS HiMA Figure 5.1. Transport of the asphalt mixture with 65/ HiMA to the trial sections in 2013 the temperature of the mixture in a truck bed after loading at the mixing plant (photo ORLEN Asfalt) Figure 5.2. Lay-down of the mixtures with 65/ HiMA on trial section in 2013 change in the asphalt mixture temperature during compaction (photo ORLEN Asfalt) Figure 5.3. Lay-down of the mixtures with 65/ HiMA on trial section in 2013 distribution of mixture temperature behind the paver (photo ORLEN Asfalt) 21

22 Dynamic viscosity [mpa.s] HIGHLY MODIFIED BINDERS HiMA In 2014, successive sections incorporating another type of HiMA binder with a bit lower penetration (Pen@ ) - 45/80-80 HiMA were completed. These were: August 2014, road No.793 near Myszków, Road Administration in Katowice, length m, wearing course of AC11S, October 2014, road No.928 at Kobiór, Road Administration in Katowice, length 800 m, wearing course of SMA 11S on a railway bridge deck, October 2014, Skawina by-pass, wearing course of SMA 11S, length m, Skawina Road Administration. 6 TECHNOLOGICAL GUIDELINES 6.1. Viscosity dependence on temperature Figures 6.1. to 6.3. show the characteristic viscosity curves of HiMA before ageing and after ageing that can be used to determine the viscosity-temperature characteristics. However, given the unusual characteristics of the binder resulting from the reversal of the asphalt-polymer phase and the specific characteristics of the polymer used, using the viscosity-temperature relation to accurately determine process temperatures does not seem to be very appropriate. Temperatures defined in this way are only approximated. End of compaction Start of compaction Mixing with aggregate Temperature [ C] before RTFOT after RTFOT Figure /55-80 HiMA viscosity curves before and after RTFOT ageing (on the basis of test results obtained by ORLEN Laboratorium sp. z o.o.) 22

23 Dynamic viscosity [mpa.s] Dynamic viscosity [mpa.s] HIGHLY MODIFIED BINDERS HiMA End of compaction Start of compaction Mixing with aggregate Temperature [ C] before RTFOT after RTFOT Figure /80-80 HiMA viscosity curves before and after RTFOT ageing (on the basis of test results obtained by ORLEN Laboratorium sp. z o.o.) End of compaction Start of compaction Mixing with aggregate Temperature [ C] before RTFOT after RTFOT Figure / HiMA viscosity curves before and after RTFOT ageing (on the basis of test results obtained by ORLEN Laboratorium sp. z o.o.) 6.2. Process temperatures As noted earlier, according to the authors, relying on the viscosity of the binder when determining process temperatures leads to their overestimation in the case of modified binders, particularly when using HiMA products. The reason is the change in binder characteristics caused by specific characteristics of the polymer used for modification (i.e. low viscous SBS with vinyl groups). Unlike typical SBS polymers, it does not cause 23

24 HIGHLY MODIFIED BINDERS HiMA such problems during the treatment of polymer-modified binder in temperatures above 100 C. Table 7.1. presents a proposal for process temperatures at the lab, mixing plant and construction site. Table 6.1. Process temperatures [ C] at the mixing plant and construction site. 25/55-80 HiMA 45/80-80 HiMA 65/ HiMA Laboratory: Compaction temperature: Marshall sample or gyratory press Component temperature at the mixing plant: Binder pumping over 170 over 170 over 160 Short-term binder storage at the mixing plant up to 190 up to 190 up to 190 Long-term binder storage at the mixing plant up to 160 up to 150 up to 140 Ready hot-mix temperature in the mixing plant's mixer: Asphalt concrete (AC) max. 185 max. 185 max. 175 Stone Matrix Asphalt (SMA) max. 185 max. 185 max. 175 Porous asphalt (PA) max. 185 max. 185 max. 175 Mastic asphalt (MA) max. 190 max. 190 Temperature on site: Minimum temperature of asphalt mixture in paver hopper End of course effective compaction temperature >130 >125 >120 Note 1: Temperature data presented in Table 6.1. have been defined on the basis of preliminary conclusions from experimental sections and relate more to favorable weather conditions. They may change as a result of further experience. Current data are available on the website of ORLEN Asfalt, in the tab Dla laboratoriów (For Laboratories). Please check the validity of information. Note 2: Temperatures provided in Table 6.1. do not apply to mixtures supplemented by an agent intended to reduce the temperature for its production and placement (for WMA) Binder samples at the lab The laboratory receives binder samples from ORLEN Asfalt in metal packaging (closed cans) or, in exceptional cases, in small cardboard containers lined inside with aluminium foil (volume of about 1 litre). The way such binder is handled has a major influence on the test results of both binder and asphalt mixtures. It should be remembered that a binder sample which is heated and/or overheated in the drier multiple times may harden significantly. Multiple heating of binder samples should therefore be avoided. We suggest using a greater number of small samples (for one-off use) rather than a single, large binder-holding container. If it is necessary to use binder from one, large container, it is recommended to heat the container for the first time to achieve homogenisation through mixing, and subsequently to pour into a few smaller containers to be used later. 24

25 HIGHLY MODIFIED BINDERS HiMA The handling of HiMA samples for laboratory tests is presented in Table 6.2. Table 6.2. The temperature [ C] of sample heating at the laboratory The size of the sample in the container 25/55-80 HiMA 45/80-80 HiMA 65/ HiMA container with up to 1 litre in volume, - heating time up to 2 hours container with a volume of 1 to 2 litres, - heating time up to 3 hours container with a volume of 2 to 3 litres, - heating time up to 3.5 hours container with a volume of 3 to 5 litres, - heating time up to 4 hours container with a volume of more than 5 litres, - heating time up to 8 hours max. 180 max. 180 max. 175 max. 180 max. 180 max. 175 max. 185 max. 185 max. 180 max. 185 max. 185 max. 180 max. 140 max. 140 max. 140 Additional comments: the container must not be tightly closed, under no circumstances should the samples be heated at a temperature exceeding 200 C, after the samples are heated in the containers, they should be homogenised by mixing, taking care not to introduce air bubbles into the sample. The maximum mixing (homogenisation) time is 10 minutes, binder samples obtained from the extraction of asphalt mixtures as per PN-EN , PN-EN , PN-EN should be tested promptly upon extraction in order to avoid reheating HiMA binder storage During the storage of highly-modified binders HiMA, the same principles and recommendations apply as with other modified binders. As always, it is recommended to use the binder in the shortest possible time after delivery, and if stored for a longer period, it is recommended to reduce the temperature to approx C (depending on the type of HIMA and set-up of asphalt plant heating system) and to mix it in the tank (circulation). Other notes: before each change in the type or grade of binder in the tank, it should be verified that the tank is empty, HiMA should not be mixed with other binders. The mixing would markedly downgrade the performance of the binder and affect the durability of the pavement, multiple heating and cooling cycles for HiMA are not recommended Asphalt mixture production In the course of binder mixing with aggregate, ageing processes accelerate rapidly (a very thin layer of binder over aggregate, very high temperature and oxygen access), therefore wet mixing time should be carefully selected. Bearing in mind this fact, HiMA binders should not be overheated and the indications in Table

26 HIGHLY MODIFIED BINDERS HiMA should be followed. The maximum production temperature should never be exceeded, even to improve workability and compatibility on the construction site. The storage period in the tank of a mixture with HiMA depends on its insulation performance and should not be longer than that adopted for mixtures with 45/ Temperatures provided in Table 6.1. do not apply to mixtures supplemented by an agent intended to reduce the temperature for its production and placement (for WMA). ORLEN Asfalt did not perform compatibility tests for such mixtures with HiMA, therefore their use is the responsibility of the asphalt mixture manufacturer Asphalt mixture transport The same rules for the transport of mixtures apply as for other polymer-modified binders. Attention should be paid to covering the mixture with a tarpaulin Placement When placing mixtures containing highly-modified binder HiMA, the same principles should apply that are used with 45/80-65 modified binders. The number and type of rollers as well as number of passes remain unchanged Acceptance tests The same testing methods as with standard binders are used for the acceptance of asphalt mixture courses with HiMA. Where checks include the determination of polymer content in the recovered binder, it should be noted that with high polymer content the result could be less precise. 7 CLOSURE Several years of research work to develop and launch the production of a new group of highly-modified SBS binders referred to as HiMA ended in 2013 with the placement the first experimental section in Poland. Having analysed the results of binder and asphalt mixture tests, as well as conclusions from the placement process, we are confident that binders of this type will soon become an important part of ORLEN Asfalt's offering. They will also be an important step towards more durable asphalt pavements in our country. The tests presented in the publication were conducted at: ORLEN Laboratorium sp. z o.o. (laboratory accredited in PCA No. AB 484), Plock, Poland Research Institute of Inorganic Chemistry, Inc. (VÚAnCh), Czech Republic Gdansk University of Technology, Faculty of Civil Engineering and the Environment, Gdansk, Poland Ekonaft sp. z o.o. (laboratory accredited in PCA No. AB 496), Trzebinia, Poland 26

27 HIGHLY MODIFIED BINDERS HiMA LITERATURE AASHTO TP 70: Standard Method of Test for Multiple Stress Creep Recovery (MSCR) Test of Asphalt Binder Using a Dynamic Shear Rheometer (DSR). Anderson R. M. (2011), Understanding the MSCR Test and its Use in the PG Asphalt Binder Specification, Asphalt Institute. Kluttz R., J Richard Willis, Andre Molenaar, Tom Scarpas and Erik Scholten (2012), Fatigue Performance of Highly Modified Asphalt Mixtures in Laboratory and Field Environment, 7th RILEM International Conference on Cracking in Pavements. Kluttz, R. Q., A. A. A. Molenaar, M. F. C.van de Ven, M.R. Poot, X. Liu, A. Scarpas and E.J. Scholten. Modified Base Courses for Reduced Pavement Thickness and Improved Longevity. Proceedings of the International Conference on Perpetual Pavement, October, 2009, Columbus, OH. Kluttz R. Q., E. Jellema, M.F. Woldekidan and M. Huurman, Highly Modified Binder for Prevention of Winter Damage in OGFCs, Am Soc. Civil E., Timm, D., M. Robbins and R. Kluttz. Full-Scale Structural Characterization of a Highly Polymer-Modified Asphalt Pavement. Proceedings of the 90th Annual Transportation Research Board, Washington, D.C., Timm, D.H., M.M. Robbins, J.R. Willis, N. Tran and A.J. Taylor. Field and Laboratory Study of High-Polymer Mixtures at the NCAT Test Track. Draft Report, National Center for Asphalt Technology, Auburn University, Timm, D., Powell, R., Willis, J. and Kluttz, R. (2012), Pavement Rehabilitation Using High Polymer Asphalt Mix, submitted for the Proc. 91st Annual Transp. Res. Board, Washington, DC. West R., Timm D., Willis R., Powell B., Tran N., Watson D., Brown R., Robbins M., Vargas-Nordcbeck A., and Nelson J., "Phase IV NCAT Pavement Test Track Findings". Draft Report, National Center for Asphalt Technology, Auburn University, February Willis, J., Timm, D., Kluttz, R., Taylor, A. and Tran, N. (2012), Laboratory Evaluation of a High Polymer Plant-Produced Mixture, submitted for the Assoc. Asphalt Paving Technol. Annual Meeting, Austin, TX. 27

28 HIGHLY MODIFIED BINDERS HiMA TECHNOLOGY, RESEARCH AND DEVELOPMENT DEPARTMENT (TRDD) Company department at ORLEN Asfalt within the production division. Active from the company's foundation in The TRDD deals with production technology, tests and development research on binders and asphalt pavements, technical marketing and new product development. It also offers technical consultancy to customers on the application of bituminous binders manufactured by the company. The TRDD achievements include patent applications, gold medal at the International Invention Exhibition IWIS 2007, and the prize awarded by the Polish Minister of Science and Higher Education for achievements in the area of inventions. Technical consultancy is available for the company's customers at: END OF TEXT 28