106 831 'THS__ ummartnrmw‘mm autumn-mt " mmmmut; 6.0.DOWD 1035' f ,1; r. ‘ . /~ , r ‘ K301 a/‘K V, 1'9“: («pkg x“ « CL ‘ /" f I"/ k t. t. t * ('( t7 5» Cy ,(. t, («EC 2. L) An Investigation of the Use of Emulsified Asphalt with Sand and Clay A Thesis submittoé to The Faculty of MICHIGAN STATE COLLEGE of AGRICULTURE AND APPLIED SCIENCE By G ° 04,139...” Candidate for the Degree or bACHELOR OF SCIENCE“ March 1935 THES'“ CONTENT Forward............................................. page 1 Introduction.................1,..................... “ 2 The Investiga£1on................................... " 8 Conclusion.......................................... ' 26 BibliographyOOOO00.00.00.000...00.000.000.00...0.0... u 28 1021910 3. FORWARD "An Investigation of the Use of Emulsified Asphalt with Band and Clay” was chosen for my thesis because I believe that there is a great deal that can be learned from such an investigation which will be of great value in the construct- ing of secondary road surfaces both now and in the future. i believe that the experience obtained in performing this thesis has been of great value in that it is doubtless ex- perience which I could not have obtained otherwise. I wish to thank the Civil Engineering Department for the use of the necessary equipment; to thank Mr. E.A.Finney for his aid, advice and criticism; and to thank the American Bitumuls Company for the emulsion.used in the investigation. JWJ W -2- INTRODUCTION In the United States there are more than three million miles of roads of Which more than two thirds are earth roads. Until very recently the public demanded better main roads with little thought of improving the secondary or feeder roads. But the time has now come when the average person is beginning to realize the importance of improving the vast milage of un- improved roads. The pe0ple living in rural districts have for many years supported the various state highway programs with the hope that they too might obtain better roads -- which are a neces- sity of community life. it is over these roads that commodities consisting prin- cipally of foodstuffs vital to the life of the nation are carried. because of the present-day economic conditions, a large amount of research has been carried on in order to dis- cover a way of building cheaper surfaces which will require little upkeep and yet will be adequate to handle the demands pladed upon them. To build cheaper roads it is necessary to use the mater- ial at hand in so far as possible along with some type of bonding material. With this in mind this investigation was carried on, using both fine and coarse sand, and clay as the materials, with emulsified asphalt as the bonding material, making use of the mix-in-place method in order to eXperiment with the construction of a cheap durable road surface. -5- This investigation will be limited to the state of Michigan although it is a poor state to use for this study because of its abundant supply of natural material such as sand, clay, and gravel. Sand and clay are very common and very widely distributed materials. Sand-clay roads have been constructed in many sections of the country under various conditions. In this study I desire to determine the suitability of various sand- clay mixtures when mixed with emulsion, which will prove to be suitable under all weather conditions for light-traffic roads. -Sand consists of small particles of rock. It has very little, if any, power of cementation because it undergoes no further decomposition under weathering. When wet, each parti- cle is surrounded by a film of water which possesses some binding power. Thus a sandy road may, when wet, producee.c1 surface that is comparatively firm and stable. However, when dry, the sand has no way of being bonded together. Each particle separates from its neighbor, thus giving no firm surface and hence making travel difficult if not trea- cherous. Clay on the other hand produces a very firm and stable road when dry because clay possesses cementing properties. But, when wet, clay becomes plastic, sticky, or slushy, de- pending upon the amount of water present. Clay is composed of small particles of stone dust which do not possess mech- anical bond as do the sand particles when wet. Thus a wet clay road is as bad, if not worse, than a dry sandy one. a 1; he: .4 -4- A mixture of sand and clay can overcome many of the dis- advantages of either the sand or the clay, when used alone. Such road surfaces, made of sand and clay,will prove satis- factory or unsatisfactory depending upon the proportions of the sand and the clay that they possess. A well proportioned sand-clay surface will prove to be a good surface both in dry and wet weather because it possesses the resisting power of the sand in wet weather and the cementing power of the clay in dry weather. Sand and clay, as I mentioned above, have often been comp bbned for road surfaces and it is this frequency of their use together that has given them.the official title of "sand- clay" roads. The term "sand-clay" road is applied to an earth road which is surfaced with especially selected or pre- pared earth containing sand and clay combined in such prepor- tions as to increase the resistance of the road to wear. The theory of a sand-clay mixture is that the sand grains shall be in contact and interlock with an amount of clay Just sufficient to fill the voids, hold the sand particles together and prevent disintegration in dry weather. The road receives its stability from the sand and must contain enough of this aggregate to support the traffic and resist grinding and crushing action. The purpose of the clay is to act as a binder for the particles of sand and the use of the preper amount of clay is absolutely essential if this type of road is to be a success. If an excess of clay is used in the mixture the grains of sand, which are forced out of contact with each other, are free to move about in the -5- mass so that they offer no more resistance to pressure than if the entire mass were made of clay. If an insufficient amount of clay is present, the mixture will lack the required binding power and will disintegrate. Because of the extensive application of surface treatment in the construction of low cost roads and the great need for further information on this subject, representatives of the tar industry and the Bureau of Public Roads have recently made a field and laboratory study in North Carolina of surface treated roads in which tar was used. This particular type of treatment consisted essentially in the application of a light tar to the untreated base followed by an application of hot tar with a cover of mineral aggregate, a third application of tar being applied with a mineral aggregate cover after the surface had been subjected to traffic for a period of time. This method of treatment was designed to provide a wear-re- sisting surface that would adequately protect the base from deterioration and which would be economically maintained in a satisfactory condition. Various investigations,with different materials,have been conducted from time to time, some of which have proven very successful while others were not so successful. In all these investigations however, asphaltic emulsions seem to have been left in the background, supposedly because of their newness in the field. New I believe that a sand and clay roadbed with a binding of asphaltic emulsion has a great many advantages over these other types. By the term asphaltic emulsion or emulsified asphalt, we -6- mean pure asphalt dispersed, for economy and convenience in using, into ultra-microscopic sized droplets, dispersed in water as the suspending medium for giving the proper fluid- ity. An emulsion saves the cost and inconvenience of heating, eliminates the danger of over-heating which is detrimental to the efficiency of the surface and makes application pos- sible by inexpensive equipment. Its high penetrating quality permits a high percentage of aggregate without affecting the prOper coating with asphalt and enables the asphalt to infiltrate to the very bottom of the coarse layer. When used cold, it is practically the same temperature as the aggregate to which it is applied; hence, there is no sud- den congealing to affect its infiltration. It may properly be used on moist or wet aggregate elimin- ating many wet weather delays. The likelihood of excess asphalt or fat spots is minimized ---thoroughly non-skid surfaces are characteristic of emul- sion construction. It permits the use of a wide variety of aggregate that would not always be suitable for binding by penetration methods. In light surface-dressing work it sets quickly so that there is no throwing or spattering upon cars using the sur- face immediately after its application. With these very apparent advantages in mind, I set out to investigate the feasibility of mixing an asphaltic emul- .. 7. sion with various proportions of sand and clay in order to find a surface that would resist wear and weathering and be suitable for a secondary road. THE INVESTIGATION After deciding to continue the investigation carried on by R.C.Monnett and J.L.Scott, I collected the required material to carry on my problem. I decided to study the effects that different sands have in the mixture while at the same time leaving out silt. This problem was carried on with Just one asphalt which passes the requirements shown later. The sands I used were concrete sand which is a course sand and dune sand which is a fine sand. The mechanical al- alysis of soil was run on a sample of each sand and clay. This analysis was run by the hydrometer method under the dir- ections of a bulletin by G.J.Bouyoucos of Michigan State College. Various mixes were then made varying the amounts of sand and clay content, using the method of obtaining percentage of ingredients used in the design of sheet asphalt pavement. The liquid limit test was run on each sample to determine the amount of water it would be necessary to use in the sample. These mixes were then made using 9 percent by weight asphalt in all the mixes. All the samples were mixed by hand. After the samd and clay were thoroughly mixed, the amount of water was added that would give the sample its liquid limit. After the mixture was thoroughly mixed the asphalt was added. This was then mixed thoroughly and allowed to stand for a period of 24 hours. At the conclusion of this time the sample was compressed into a pat 6 inches in diameter and about 1% in. -9- in depth. These samples were placed outside where weathering action would take place. While outside, they were subjected to both freezing and thawing action. These samples, shown in Figs. 4 and 7 were left outside for 5 weeks and then dried in the laboratory. The shear test was run on these samples and curves, as shown on plates 3 and 4;were drawn. After this set of samples was mixed, I made up samples of the same percentages by weight as the above samples. One set was made with samples 4 inches in diameter and about 2% in. in depth, which were cured in the laboratory. These samples are shown in Figs. 3 and 6, and are used as comparison same ples. The other set of samples were 2 inches in diameter and approximately 2 inches in depth. These samples were placed in the water bath and their weights were recorded each day for a period of two weeks. The absorption percentage was obtained from.this data and curves, as shown in plates 1 and 2 were drawn. Figs. 2 and 5 show these samples. All samples were compressed into pats by the machine shown in Fig. l, which is shown below. There was applied to each pat the equivalent of fifteen hundred pounds per square inch of pressure, which is approximately the pressure exerted by an average sized road roller. A new set of samples was made using a constant percentage of sand and clay, while increasing the percent of asphalt. This was done after the previous samples had been cured. Samples 1A and 1B shown in Figs. 3 and 6 respectively, show 710' a very good color. These samples contain 70 percent sand, 21 percent clay and 9 peccent asphalt. From all outward appearances there is just the right amount of asphalt, sand, and clay in these samples. Samples 5A and 5B have 71 per- cent clay, 20 percent sand, and 9 percent emulsion. The color of these pats was a Very light color, making them appear as if they hadn't had a high enough asphalt content. It was with this mix that I varied the content of asphalt, attempting to get a mix whose color approximated that of samples 1A and 1B. It was found that with a mix of such high clay content, it would be economically impossible to mix enough aSphalt with the mix and obtain a good dark color. These samples tn which I varied the asphalt content, were placed in the water bath and the percentage of absorption was obtained for a 7-day period. These samples are shown in figures 8-11. Table 2 gives data obtained from samples in which I used varying percents of asphalt, while running the clay down to zero. Table 3 gives data obtained from samples in which a combination of coarse and fine sand was used with a con- stant percent of asphalt. The samples for these last two tables were oven cured and allowed to come to room temperature before testing. The shear test was run by placing a sample in a 2 inch cylinder with an inch and one-half knife-edged throat, and then the 'pressure was noted at which the briquette pushed through the throat. -11- Particular note should be made of the deterioration of the samples as shown in the pictures. The samples that cracked the worst were the ones that had the higher per- cents of clay in them. The samples in the water bath crack- ed badly. Sample 5A of Fig. 4. cracked so badly that it was impossible to cut out briquettes in order to run the shear test on that sample. The samples in which the asphalt con- tent was varied cracked up very condiderably, showing that the clay content was too high and not enough sand was pres- ent to give the necessary bonding property. Very strangely the shear increased as the percentage of clay increased. However I believe that smaller shear can be had with safety, when.using a mix of less clay and more sand. I believe that the shear increased as it did because the clay became so brittle when dried and thus caused a much tougher sample. Tests for wear and abrasion were to have been run on the treadometer, using various mixtures. But these tests could not be run because the use of the treadometer was not avail- able, and because of an insufficient amount of time for further investigation on this subject. I believe that a great deal of valuable information could be obtained by making such tests. I hope that I may some day be able to run these and many more tests and thus carry this investigation on to its true conclusion. It is certain that a great deal of worth while work can be done in this field, since emulsified asphalt is a compara- -12- tively new surfacing material. It is very economical and easy to apply, and makes a very good road surface. Therefore I believe that it is one of the best materials we have avail- able today for surfacing low-type roads. Fig. 1. Compression Machine. -15.. Fig. 2. Coarse Sand Mix--absorp- tion test; 14 days in water. Fig. 3. Coarse Sand Mix--lab. cured. Fig. 4. Coarse Sand Mix--a1ternate freezing & thawing for 5 weeks. -14- Fig. 5. Fine Sand M11--absorption test; 14 days in water. .-'J‘ Fige 60 Fine sand Mix--labe cured. —'\.\‘ Fig. 7. Fine Sand Mix--alternate freezing & thawing for 5 weeks. - 15- Fig. 8. Coarse Sand & Clay with Varying Asphalt Content-~lab. dried. Fig. 9. Same as Above--subjected to 7 days in water. Fig. 10. Fine Sand & Clay with Varying Asphalt Content-lab dried. Fig. 11. Same as Above-~subjected to 7 days in water. -17- Requirements for Emulsified ASphalt XRM Grade 0 Bitumuls XRM is a homogeneous emulsion of asphalt, water, emulsifying and stabilizing agents. It is miscible with pure water in all preportions and shows no separation of asphalt, after thorough mixing, within thirty days after delivery, pro- vided separation has not been caused by freezing. When tested as hereinafter specified, the emulsions conform to the follow- ing requirements: Viscosity - Saybolt Furol - 60 cc. at 25° C. Not more than 60 sec. Miscibilityz - - No appreciable separation in 2 hrs. Mixing - -------- Break, not more than 2 % Total combined amount of all saponifiable substances, including petroleum acids - - - -Not more than 1 % Residue at 163° c. 3 hrs., 50 gms. Not less than 55 % Settlement, 10 days - - - - - - - - - Not more than 3 % Demulsibility - ----------- Not more than 1 % The residue obtained from the test at 163° 0, shall con- form to the following requirements: Penetration at 25° C. - - - - - - - - --- 200 to 300 Solubility in carbon disulphide- - Not less than 95% Ductility at 25° C. ------- Not less than 10 cm. Ash - - - - - - - - ------- Not more than 3 % 01 IF U (0 H ’0 014:0:me 70.0 57.0 44.6 52.4 20.0 -13- Key for Tables 1, 2, and 3. shear in lbs. " asphalt by weight fl 0 per sq. percent of absorption in. N N on absorption samples 9' weathered " lab. cured ' coarse sand by weight “ fine 70.0 57.0 44.6 32.4 20.0 clay " n '7 TABLE 1 C. X. 21.0 9.0 54.0 9.0 46.4 9.0 58.6 9.0 71.0 9.0 21.0 9.0 34.0 9.0 46e4 9.0 58.6 9.0 71.0 9.0 819 955 1401 2005 2350 1257 1544 1475 1892 1397 552 1141 1090 965 1550 756 1259 1234 1535 1710 '1 VP 725.45 874.5 1085.5 1288 1485.5 724.25 1271 1644 1415.5 1586 3.23 4.105 6.535 7.845 10.125 2.85 4.98 5.575 7.885 9.025 P‘ ta 2 +4 c> <0 G) -q o: (n e- on to P‘ o 01 .e on re #4:! tn 5. ca N) DAD-O a: rd ca re 0.8. 20.0 20.0 20.0 20.0 20.0 0.8. 75.6 81 86 91 62 72 82 20.0 20.0 20.0 20.0 20.0 FeSe 75.6 81 86 91 62 72 71.0 71.0 71.0 71.0 71.0 71.0 71.0 71.0 71.0 71.0 -19- 10.0 11.0 12.0 15.0 14.0 10.0 11.0 12.0 15.0 14.0 TABLE 2. 15.4 15.4 10 10 5O 50 2O 20 10 CDCDCDCDCD<0< Vw 676 686 705 657 516 245 957 198 1545 1587 1156 1209 1055 1755 1585 1470 1469 1221 889.5 1128 1085 1178 1448 1702 1292 1098 '1000 998 1421 860 1062 975 1070 6.9 6.4 5.84 5.94 l h \ 5.045 7.94 6.94 6.5 7.08 7.92 NO. 14 15 16 17 18 19 20 :z 0 l4 a: :4 to l4 O (D a) '4 O) tn ab 0' CO I“ COS. 75 85 95 0.3. 17.75 50,5 55.25 19 58 57 20.25 40.5 60.5 21.5 45 65.25 75 85 95 F.S. 55.25 50.5 17.75 57 58 19 60.5 40.5 20.25 65.25 45 21.5 10 2O 20 10 10 TIBLE 5. 20 20 2O 15 15 15 10 10 10 -20- ~Q ‘4 ~l '4 NJ '4 a) <0 G) <0 K) (O «D (D G) (O «D (D ¢> >4 VN 555 1552 1299.6 1044 451 255 225 .< 22 486 599 656 756 958 955 686 744 822 577 597 499 ..u4‘*io an... a 01.. 7.". p e . .1... . — 9. It _ ...za.s.il. . i l .e' . p -w g.- I o I L', 3 | . If - -.- . U ..--...-_f-___..-.._1 . . . , t I . aw--.‘ O i ,; , 1 I ! v V‘ . I .. 1 "’79? .. I»... ,- '1' ' A .1 . . o 7“! t .e .. 9 «»4 o J l .. ....¢ sol up . o. a“ a -.... 01....” . ... - .s... .m. .0 . . l . . a. .—.—.—-~- ~ «~- I vf' III- »|. II. n I .uc Im'w Or. “A:\ ACNLAN S. c ' £509.! ‘09}- 7...". HACL he... awe. mc we‘ve-c .‘l l'.wdl96a . .eeue.| e. e 1,. 0 MACLACbcuau a. me 36> r 0.. MRCL ACHI. Ah's. aNC OOS'L‘K _ . . N W . . '0 f .I'- Ilff.’ .77. Mc am Kw HACL ACHLA'n 9 -25- CONCLUSION As a result of this investigation I feel that the follow- ing conclusions are warranted;- 1. '2. 10. Coarse sand gives a stronger and better mix than fine sand. A combination of coarse and fine sand gives a desirable mix provided that the mixture contains about three quarters of coarse sand and one quarter of fine sand. Waggh gigf/reg/rilvgt oughening a mixture . Percentages by weight of aSphalt of over 9 are not econom- ical and do not give good results. These between 7 and 9 are the best for this type of cold-mix road surface. When either fine or coarse sand is used alone with clay and asphalt, a good durable mix demands about 70 % sand, 20 % clay and 8 or 9 % asphalt. A mix of the above proportions will withstand extreme weather conditions without deterioration. Samples with sand content above 81 % and with clay content above 40 % are unstable no matter how much asphalt is add- ed. Cracking will take place on any sample that contains an excess amount of clay. This means mixtures of over 40 % clay. Absorption will be the least in samples with the least amount of clay. Shear increases as the percent of clay increases, but it cannot be used as a guide because in all other respects an increase in clay decreases the strength and serviceability Bf the mixture. 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(b) Tarvia Retread. ‘ BOUYOUCOS,G.J. A Comparison of the Hydrometer Method and the Pipette Method for Making Mechanical Analysis of Soils, with.New Directions. 7 DO! CHEMICAL COMPANY Treatment of Secondary Roads with Calcium Chloride THE OHIO OIL COMPANY (a) Lincoln-its. (b) Linco Cut-Back Asphalt. GRIFFITH,JOHN H. Physical Properties of Earths "Erma use out H'Q. {NC . IOSTON A .L H .c s..- .,.L. 4c a e. MACLACHLAN’S. 1_~c,sosro~ S. INCL, BOSTON :HLANZ MACLAC _ :, ,i N AI‘H l- V41. ~ in. .c ,. . 1.5.0... . .... .. Alfie-files. .. .. 1 .4. 3. ; l 3; i