TITLE: by: A New Mix Composition to Increase the Storage Life of Indonesian Bitumen Emulsion M Hermadi and A B Sterling TRL Limited Crowthorne Berkshire RG45 6AU United Kingdom PA3328198 PA3328/98 HERMADI, MAND A BSTERLING (1998). New mix composition to increase the storage life of Indonesian bitumen emulsion. TRANSIT NEW ZEALAND 1998. Proceedings of the 9`/ Road Engineering Association of Asia and Australasia Conference (REAAA), Wellington, New Zealand, 3 -8 May 1998. 222 NEW MIX COMPOSITION TO INCREASE THE STORAGE LIFE OF INDONESIAN BITUMEN EMULSION Madi Hermadi Institute of Road Engineering Research and Development Agency Ministry of Public Work -Indonesia Dr A B Sterling Transport Research Laboratory Road Research Development Project IRE, Indonesia Madi Hermnadi is a researcher, born on August 9, 1964. Graduated from Department of Chemistry, Institute for Islamic Studies, Bandung, Indonesia, 1992. Involved on road materials research at IRE since 1985. Dr Sterling graduated in 1963 and ga 'ined his Ph.D. in highway engineering in 1975. He is an independent consultant and has been working as a Pavement Engineering Specialist at IRE as a member of the UK Transport Research Laboratory team since 1995. 1 INTRODUCTION Bitumnen emulsion is often used for pavement mixes in Indonesia, especially in locations where there is a shortage of hot-mix plants. Current formulations of emulsions have a storage life of about three months. In Indonesia the typical site storage time is frequently more than three months, nine months being quite common. This situation arises because supplies to outlying areas fend to be made only at quite long intervals. The fact that emulsions are stored for longer than three months leads to poor quality asphalt or total loss of the emulsion. IRE research in 1995 (Tjitjik, 1995) about the ways of handling bitumen emulsion showed that bitumen emulsions made in Indonesia, especially CSS type, had storage lives of only Iwo months when retained in a drum without turning. When the drums were turned once a month, the storage life increased to, typically, five to six months. This paper describes an IRE research project designed to find formulations for bitumen emulsion that will significantly increase storage life. 2 LITERATURE 2.1 Bitumen Emulsion Bitumen emulsion is a mixture of two phases, that is an aqueous emulsifier solution as continuous phase and tiny droplets of bitumen as the discontinuous phase. The bitumen particles are typically in the size of 0.1 to 5 micron and are usually stabilized by an ionic emulsifier 2.2 Emulsifier Based on the charge, there are three types of emutsifier. Those are cationic, anionic, and non-ionic emulsifiers. Indonesia currently uses cationic emulsifiers. 2.3 The Ways of Increasing Storage Stability of Bitumen Emulsion According to Stoke's law, the rate of settlement is determined by the following formula: v = 219 x gr' (dl-d2) I, where, v = the rate of settlement g = gravity r= radius of bitumen particles cl 1= specific gravity of bitumen cd2 =specific gravity of liquid phase p= viscosity of liquid phase Considering the formula, we can see the rate of settlem~ent depends upon: . Viscosity of the continuous phase. * Difference in specific gravity between the two phases, and * The size of bitumen particles. It follows that there are changes in the formulation of bitumen emulsions that may be expected to improve storage stability. They are as foltows: ~~~~~~m ~~~~~~~~~~~~~a#i 1 'a5a5E5E-aa aaaaa a) The higher the specific gravity of bitumen the faster the bitumen phase will settle. Adding kerosine to the biturnen, before emulsifying, will decrease the specific gravity of bituiiien phase which should reduce the rate of settlement. Likewise, increasing the specific gravity of the aqueous phase should also reduce the rate of settlement. b) Storage stability of bitumlen emulsion should be increased by increasing the viscosity of the aqueous continuous phase. c) Reduction of particle sizes of the bitumen phase should increase storage stability. Additional factors that should/may alter storage stability are. a) Type and quantity of emulsifying agent. b) Bitumen content andlor viscosity of the emulsion. 3 EXPERIMENT IN LABORATORY The research investigated both cationic medium setting (CMS) anid cationic slow selling (CSS) emulsions t0 find the optimum compositions by varying:. * Colloid Mill condition i.e. particle size distribution of bitumen droplets, . enmulsifiei type. * kerosene content of bitumien, * bitumien content of the emulsion, . emulsifier content of the aqueous phase, and . CaCI2 content of the aqueous phase. 3.2 Emulsifier Type Figure 1. Effect of Emulsifier Type on Settlement 1.6 6.4. 1.2 -. 1.0 0.8 0.6 04. 02. 2 3 aLAB IX mLAR3 2X C0PiANT 6 a Numb.' of ---pl.. There are only five emulsifiers currently available in Indonesia. Three of these are for CMS, namely Asfier-103, Asfier-123, Asfier-208. Two are for CSS, namely Polyram-SL and Redicote. The research examined the changes in settlement rate caused by use of each of the above. The results are shown in Figure 1 above. 3.1 Colloid Mill Condition In this investigation, bitumen emulsions in many compositions were produced using a laboratory colloid mill. The gap size and the rotor speed of the laboratory colloid mill cannot be changed. Theretore, the laboratory colloid mill cannot be adjusted to achieve the same particle size distribution as the factory colloid mill. Storage stability of bitumen emulsions produced by the laboratory colloid mill are lower than those produced by the factory colloid mill. Therefore, the first step of this investigation was calibration to determine the correlation between the storage stabilities of emulsions from the two sources. Seven bitunmen enmulsions were produced by each of the following processes: • the factory colloid milfl, * the laboratory colloid mill using a single pass and * the laboratory colloid mill with double passes. The bitumen emulsions were compared in settlement value anid thle results are shown in Figure 1 below. Settlement value is the difference in residual bitumen content, percent, between samples taken fron, the lop and bottomn of a 500 ml cylinder after storing for one or five days. Figure 1 shows that bitumen emulsion produced by a single pass through the laboratory colloid mill had higher settlement values than those produced by the factory. Those usinrg a double pass through the laboratory colloid mill had very similar settlement values to emulsions produced by the factory. Hence double passes through the laboratory mill were used for the rest of the experiments. As shown in Figure 1, the emulsifiers that produced bitumen emulsions with the lowest settlements were Asfier-103 for CMS and Redicote for CSS. These emulsifiers were used for the remainder of the experiment s. 3.3 Variation of Penetration Grade Bitumen The penetration value of the bitumen feedstock influences the storage stability of the emulsion, possibly via changes in the bitumen specific gravity (SG) and/or through the effect of bitumen hardness on particle size distribution. The influence of bitumen penetration on the settlement of emulsion is shown on Figure 2. Figure 2. The Influence of Penetration on Settlement of Emulsion 0 a 0 ? 0 6 : 0 00 0 J 03. P-11.1.. n of I-r O o -4m1-lo 223 1 1 --- - 0 1 224. Figure 3. The Effect of Adding Kerosine on Penetration 500 40011' r c0 '4 CL 300 _____ 250 -__ i___ - - 200. ____ - -__ ._ 1s0 -- ;7- ~7- -- __ __ - 50, 0 -+-, '--I, 450 400 'i0U:U).92
0 1 69 3 45 '435 5 26 6.19 714 8 11 % of Kerosine Bitumens produced in Indonesia by Pertamina are AC pen 60/70 and AC pen 80/100, The literature indicates that pen 180/200 is a more common bitumen grade for use in production of emulsion. In order to produce a bitumen of 180/200 grade, 60/70 was blended with kerosene. The effect on the penetration grade, of adding kerosene to 60/70 bitumen is shown in Figure 3. As may be seen in Figuire 3, above, 4.3% kerosene must be added to the bitumen to increase the penetration value to 200. This also has the effect of reducing the bitumen SG. 3.4 Variation of Bitumen Content Increasing the bitumnen content of a bitumen emulsion increases both emulsion viscosity and storage stability. The influence ot bitumen content on storage stability and viscosity of bitumen emulsion is shown in Figures 4 and 5. 350 300 250 200 150 100 50 Figure 5. The Influence of Bitumen Content on Settlement of Emulsion * css.1.25C * CMS-2,50C 60 63 65 68 70 75 80 Biiurnen Conteni (%l Figure 5, above, shows that a higher bitumen content leads to increased storage stability of bitumen emutsion. Bitumen contents used in current production are designed to achieve emulsion viscosities complying with the relevant specifications. The specified viscosity range for CSS-1, at a temperature of 25'C, is 20 to 100 seconds. For CMS-2 it is 50 to 450 seconds at a temperature of 500C. Considering Figure 6. the ideal viscosity of CSS-1 is 60 seconds which can be reached at bitumen content of 70 to 72 %. The minimal residue content of CMVS-2 is 65 0/, so bitumen containing about 10 0/ of kerosene would leave 650/ residue if 72 0/ of cutback bitumen emulsion were used in the emulsion. 3.5 Variation of. Emulsifier Content Figure 4. The Influence of Bitumen Content on Settlemet of Emulsion 4~~~~~~~- ; c ssiii( day) __________________________i days) & CMs.2 __ __ __ _ __i day) 60 63 65 68 70 75 80 -- Bitune,, Conlicni (%i The amount of emutsifier used in bitumen emulsion depends on the bitumen content of the emulsion. There is an optimal content of emulsifier to achieve the highest value of storage stability. If the content of emulsifier is too low, the bitumen droplets will soon precipitate. If the content of einulsifier is too high it can cause the emulsion to bubble and excessive air content can destroy the emulsion. The influence of emulsifier content to storage stability of bitumen emulsion is shown in Figures 6 and 7. Figure 6 shows that the optimum content of emulsifier Asfer-103 is 0.4 % for CMS-2 bitumen emulsion, Figure 7 shows that the optimal content of Redicote emulsifier is 0.48 % for CSS-1 biturnen emulsion. At those emulsifier contents, the emulsion had the lowest value of settlenient. ~1 __ __ __ j1__ 6 Ea'i~
W, W W a A A 2 a 2 W IN a a W, a 19 12 5 - aa au-a aa au yWa-a Figure 6. The Influence of Emulsifier Content on Settlement of Emulsion CMS-2 Type Figure 8. The Influence of CaCI 2Content to Sattlement of Emulsion 5'.5 > 3. 1 C' 2.5. 2 C', 1,5 0.50 *.,1 day1 6 0 0.1 0,2 0.3 0.4 0.5 0.6 0.7 0.1 Ernuis~ifi, Coiiont 1%) Figure 7. The Influence of Emulsifier Content on Settlement of Emulsion CSS-1 Type ., 3 0) 0 * 1 day *5 days 0 0.1 0.2 0.3 0.4 0.5 0.6 0.1 0.8 E nuls~ifier Conient % 3.6 Variation of CaCI 2 Sometimes cationic emulsifiers combine with unexpected anions and are precipitated as sediment. Calcium Chloride, in cationic bitumen emutsion, acts as a stabilizer that inhibits such sedimentation. CaCI 2also increases the density of emulsifier solution and hence increases the storage stability of the emulsion. The influence Of Ca1C1 2on storage stability of bitumen enmulsion is shown in Figure 8. Figure 8, below, indicates that the optimnal content of CaCI 2is 0.3 %. This condition gives the best storage stability of CMS-2 bitumen emutsion. The optimal content of CaCI 2could be different if the quality of water in the emulsion changed. cad?2 Content (%1 * cM5.3I 1day 5 days A css-i 25 I day 5 days 3.7 Optimal Composition of Bitumen Emulsion Using the results of the experiments described above, the optimal composition of bitumen emulsion was determined and is presented in Tables 1 and 2. Table 1. Composition of Bitumen Emulsion CMS-2 Type Element of emulsion Composition CMS-2 Type 'Modified Conventional Bitumen, % 65.00 63.00 Kerosine, % 7.00 7 00 Emulsifier, % 0.40 0.30 Hl-c, % ____0.40 0.30 CaCI,. % 0.30 0.10 Water. % 27,90 29.30 Table 2. Composition of Bitumen Emulsion CSS-1 Type Element of emulsion Composition CMS-2 Type Modified Conventional Bitumen. % 65.20 59 00 Kerosine. % 2.80 1.00 Emulsifier, % 0.48 0.40 Hcl, % _____ _0.48 0.40 Cad.. .% _________ ~0 30 0 10 Watec% - ~~~~~~30 74 39.10 3.8 The Monitoring Quality Result of Modified Bitumen Emulsion Monitoring the quality of modified bitumen emulsion CMS-2 and CSS-1 shows that it can be placed iii 9 iioviths aud will still comply with the specification. 225 s -- p _ _ _ _ _ _ _ _ _ _ _ 0.05 0.1 0.15 0.2 0.25 0.3 0 -- 226 Table 3. Quality of Bitumen Emulsion CMS-2 Type Characteristic specification CMS.2 Modified CMS.2 Converrtional Mn Max 0M M G 9 m 0 m~ M ~ Viscosiry. SF at 50Gl S 5 450 257.6 25 7.3 2.57.8 257.7 252.6 252.3 253 252.8 SettlernenI lesi, 1 daIL 0/ 0.36 04A7 -0. -07-8 (142 0.4-5 0.63 oGyit Setllement lest. 5 (lays. % 5 3.18 1,55 3.8. 4.22 3.45 34 .2 47 Coaling abilly and whly; resistance*Coaling dry aggregate good good good good good good gooui good 9(10( *Coaling ahfle spraying good good good good good good good good good *Coaling wet aggregate good good good good good good good good toodt *Coaling alber s Pray~ring ,,,,,,, od good good good good good good ,,29d0l1 good Particle cliarge lest Positive * 0 . + Sieve lesl. % 0.1 0 0 0 0 0 0 0 0 Waler content., % 28.20 2 7.21 27.45 27.33 26.48 27.27 20.51 26.13 Oil distillate. 0/% 12 6.1 6,5 6.3 6.2 6,2 6.3 6.3 6. Residue. % 65 66,8 66.8 66.2 66,5 65.5 65.3 65.6 05.4 Test on residue * Penetratron. 25"C. 100g9. 100 250 214 215 215 215 215 214 214 215 0. 1 imm -Ductility,25 0C. cm 40 '140 '140 v140 .140 '140 >140 '140 '140 * Solubility in 97.5 gg 99 99 99 gg 99 99 99 -iclrctoroelhylene. 0/ Specitic Gravity .0.958 0.958 0,958 0.958 0.958 1 0.9580.5 J8 Note: M =Months (Age 01 bitumen emuliron) Table 3, above, shows that the quatity of modified CMS-2 bitumen still meets the specification after 9 months. Table 4. below, shows that the quality of modified CSSi-1 bitumen emulsion still meets the specification after 9 months. Whereas the quality of conventional CSS-1 will not meet the specification in 3 months, and it wilt precipitate in 6 months. Table 4. Quality of Bitumen Emulsion C5SS- Type NOW, m = monrths (Age or Characteristic ISpesitication CSS-1 Modification css-1 Convenioirat Mim Mao Om 3 M m 9M m Om 3M Viscosity, SF at 25'C. s 2-0 100 48.6 48.6 48.5 48.6 20,2 19.5 Sarrierrieni lest, 1 day,0/ % 1 0.13 0.16 0.17 0.85 0.75 2.60 Salitemnent lest. 5 days. % . 5 1.03 1,23 1.82 4,23 4.30 5.23 Pardicle charge test Positif vB v v 0 il~itriren Sieve lest. %t 0.1 0 o 0 0 0 0 Emnulsion Ceenrrt mixinig test. 0/ % 2 1,30 1,32 1,33 1,76 1.80 1.83 s Water conrentl. 0/. 31.62 31.82 31.62 31.62 39.22 39.25 Settled Oit dostriate. Ot% 3.31 3.05 3.45 3.34 0.50 0.71 Resida. 0/5% 54 67.74 65.46 04.62 59.81 C597 lest on resrdu -Penetration. 25C, 100 100 250 135 135 134 135 122 123 -Ouc1)itlYity .2 .IM 40 '140 '140 '140 '140 '140 > I40o Solubility in 9 75 99 99 99 .99 99 99 Trichlofoe~irytene, 0/%______ Specific Gravity 6.96 09-62 0.62 0,962 0.1(60o 0.9(i) ______ 4. USING MODIFIED EMULSION IN FIELD EXPERIMENT A field experiment was performed in which Slurry Seal was mixed and laid to compare the use of modified and conventional CSS-1 emulsions as a binder. The experiments used emulisons, both modifted and new, that had been stored for 3, 7 and 9 months. A control sectton was also latd using new, conventional CSS-1 emulsion. 4.1 Specification of Slurry Seal Mixture Here are fottr specification of four types of Slurry Seal mixture. Table 5. Specification of Four Types of Slurry Seal Mixture Characteristic of _________Specification Slurry Seal Mixture Type I Type 11 Type 111 Type IV Gradation of aggregate, % passing:Sieve size :112 -- 100 318 *100 100 85-100 No. 4 100 90 -100 70- 90 60-85 No. 8 90. 100 65-90 45-70 40.60 No, 16 65-90 45-70 30-50 28-45 No. 30 40-60 30-50 18-34 19.34 No. 50 25 -42 18 30 10 -25 12 -25 No. 100 15 -30 10 21 7 18 7 18 No 200 10 20 5 -15 5 -i 4 .8 Residual bitumen content. 10.0 -16,0 7.5 -13.5 6,1 11.0 5.5 -8,0 % weight of dry aggre ate Apptication rate .kg/rng 3.5 - 5,0 5.5 -8.0 8,0 18.0 10.0 -15.0 based on mass ot dry aggegt Condition of Slurry Seatl Semi fluid -Semi fluid -Semi fluid -Semi fluid Mixture -Smooth -Smooth -Smooth -Smooth -Homogenous -Homogenous -Homogenous -Iomogenous -No emutsion -No emulsion -No emutsion -No emulsion run off run off run off run ott 4.2 The Quality of Material for Field Experiment of Slurry Seal The quality of bitumen emulsion and aggregate used in this field experiment is shown in Tables 6 and 7. Table 6. The Quality of Bitumen Emulsion No Ournern Enruision Cirar`actecistic of L 2 4- 6 ~8-~-9 - Viscosiry. SF at 25`C _bi.ttIL.ntioi it e5r. 1(try_ Setttliemert test, 5 (laiys Sieve rest. % cS ei ierot rri v g t %it Oit disoiiiiate. 0/ Rtesiduie I, Specitication uuiatit of fihiunren Lnmutsion Cbb.1 Modified Conven. Units Min Max ~3 M 7 M 9M m tiorral 20 10 68.5 69.2 67.3 20.5 seconds Li 0,15 0.34 0.68 0.65 % 5 1.25 2.31 4.0 7 3,77 % Positive v ). 1 0 0 0 0 %_ 2 1.50 1.70 1,80 1.s0 %/ 29.7 27.6 28.3 38.4 oto 13.25 1 3,32 1 3.12 0.50 % 57 64.2 64,8 63.7 58.6 I w. W WuuW wW uvuW W WW u w u W W Particle chaige test oitumen emulsion) 1 -: p p p pp aa a' M'5 a55 A -- a5 -uvI Specrtication Table 6. The Quality of Bitumen Emulsion (continued) utlatil 01 iiittsnrrer~ni-riil ClSS 1 cLiiaracteirstic ot No. Btium~en Emnulison ____Modified Conivelr Units Min Max 3 M - 7M 9 M timonil 10. Test on residue: Penetration, 25'C. 100g., 100 250 134 134 135 123 0.1 nim 0.1 Frimlr D uctility .25'C, cni 40 > 140 >140 '140 >'140 crrr *Solubility in 97,5 . 99 99 99 99 % Tticlriotoeithyleene 11 -Specific Giavity ____ _____ 0,9585 -0,9588 0.9587 0.9007 Table 7. The Quality of Fine Aggregate ex Cilacap Specilication Result of lest Units No. Characteristic of Aggregate Min Max Gradation ot aggregate. % passing__ ___ Sieve size 3/8 *.100 No, 4 __ _ _ _ _ _ _97.5 No 8 _ _ _ _ _ _ _ _ 82,9 No. 16 *-58.6 __ _ __ _ No 30 -39.5 No 50 _ _ _ _ _ _ _ _ 29.7 No 100 _____ 16,3 0/ No 200 *.7,3 __ _ __ _ 2 Spr152 tic G ravity _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ --lik 2,500 __ _ _ _ _ 2.630 _ _ _ _ _ *SSO 2,500 _ _ _ _ 2.690 __ _ __ _ 3 .AirpaterriAbsr,,bti,O,I enfsii 2.500O 2.790 0.25 - 3 0,15' 3 4.3 Design of Slurry Seal for Field Experiment The gradation of aggregate, ex Cilacap, is shown in Table 7 above, and meets the specification of Slurry Seal Type II. 4.4 Bitumen emulsion CSS-1 Content The content of bitumen emulsion CSS-1 type is staled base on the following formula. P = 0.05A+0.1B+0 5C whtere, P = Percentage of bitumen emulsion A = Percentage of aggregate that contain in No.8 sieve (17.1 0/) B = Percentage of aggregate passing No.8 sieve and retained on No.200 (75.6 %) C = Percentage of aggregate that pass in No.200 sieve (7.3 %/) For modified CSS-1 bitumen emulsion content, multiply the calculated content of bitumen emulsion from the formula by the correction factor of residue content 58.16-64.2. The value of 58.6 is the residue'% of conventional bitumen emulsion and 64.2 is the residue % of modified bitumen emulsion. Hence:Modified CSS-1 bitumen emulsion content Conventional CSS-1 bitumen emulsion content = 10.35 % = 12.07%/ 4.5 The Content of Cement in Slurry Seal Mixture Portland cement, chalk, and fly ash may all be used as mineral fillers in order to meet the specified aggregate gradation or to modify the time-to-break of the bitumen emulsion. We use Portland cement in this trial in order to achieve the break time of 30 minutes, the time needed in field experiment from mixing to pouring the mixture using locally produced equipment. The result of adding cement filler to Slurry Seal is described in Tables 8 and 9. Table 8. Bitumen Emulsion CSS-1 Modification Percent of Cement Breaking Time 0 60 minutes 0,5 45 minutes 1 30 minutes Optimum 1,5 20 minutes 2 15 minutes Table 9. Bitumen Emulsion CSS-1 Conventional Percent of Cement Breaking Time 0 60 minutes 0,5 45 minutes 1 30 minutes Optimum 1,5 20 minutes 2 15 minutes 4.6 Optimising Added Water Adding water in Slurry Seal is to get mixture with characteristics semni fluid, smooth, homogenous and without emulsion run off. The result of adding water to Slurry Seal is described in Tables 10 and 1 1. 227 41 1 228 Table 10. Adding Water for Slurry Seal CSS-11 Modification Adding Water Semi fluid Smoothly Homogenous Norun off 1 5 No No No No 20 No No Yes No 24 Yes No Yes No 26 Yes ___No____ Yes NO 28 Yes No Yes No 3O0) Yes Yes Yes N-1o 32 Yes Yes Yes Yes__ 34 Yes Yes Yes Yes Optimum Table 11. Adding Water for Slurry Seal CSS-1 Conventional Adding Water Semi fluid Smoothly Homogenous No ____________ ___________ ~~run off 10 No No No No 14 No No Yes No 16 Yes No Yes No 18 Yes NO Yes No 19 Yes NO Yes No 20) ~~Yes Yes Yes N 21 ~~Yes Yes Yes N 22~YesYsYe-e Note : ) = ptimum Figure 10. Simple Equipment for Slurry Seal Table 13. Pavement Condition and Traffic Before and After Application of Slurry Seal No Survace CSS-1 Modirication CSS-1 Modification CSS.1 Modification 3 Months Age 7 MonthsAg 9onhAg Condition Before After Before After Aplication Before After Apticat on -Aptication Apticafion ___Apircation Aplication ___________ _ ________ Mod Con. Mod. 1 Con. Mod. Con Avextage. cmeth t.8 00 .6 00 0 .7 Q , A.veraredeph 00c0m06 08 08 0 6 0 2. Skid Resistance 47.5 -62.5 64.7 48.3 -63 7 52 9 -63 4 65 3 3. Survace 453% good good 52.2% barik - 65.3 % good good Condition Ra-lngRavelin ___ Ravering- 4 Tiafic per day 521 51 21 5186 5186 5605 5605 15605 Note Mod = Modification Con. = Convent ional 4.7 The Result of Field Experiment of Slurry Seal Mixture The trial of Slurry Seal was laid in Jatan Jenderal Sudirman KM I-Cilacap on February 5 .1997, in Jatan Gatot Subroto KM 5 Cilacap on May 5 1997 and in Jalan Sutomo KM. 7 Pekalongan. The Slurry Seal was mixed and laid using simple equipment that can easily be built in any part of Indonesia. The equipment is illustrated in Figure 10. 4.8 Pavement Condition and Traffic Before and After the Experiment The condition of Slurry Seat and traffic when the experiment was done is given in Tables 12 and 13. Table 12. Visual Condition of Slurry Seat Mixture 5. CONCLUSIONS a) Because of the remoteness of some of its parts. Indonesia needs bitumen emulsion with high storage stability, that can be stored about 6 to 9 months. b) The storage stability of Indonesian bitumen emulsions, CMS and CSS, can be increased by changing their composition. c) The optimum composition for CMS-2 bitumen emulsion is 65% bitumen. 70/ kerosine, 0.40% emulsifier (Asfier-103), 0.40% H Cl. 0.30e/ CaCI 2and 27.90%/ water. d) The optimum composition for CSS-1 bitumen emulsion is 65,20%/ bitumen. 2.80% kerosine, 0.48% emulsifier (Redicote), 0.48% H Cl. 0.30% CaCI 2and 30.74%/ water. e) The study has shown that bitumen emulsions CMS-2 and CSS-1, with optimum composition, can be stored for up to 9 months. f) A field experiment demonstrated that changing the composition of bituinen emulsion CSS-1 to that described above does not effect the characteristics of Slurry Seal produced with this material. g) Slurry Seal, made with the new emulsion, was placed successfully after storing the emulsion for 9 months. A simple mix-and-spread machine was used that is designed for local production. Note ^ ^ to
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