HHHHI HHW U)(ON numm 7049302an on ‘ ‘ muvam momma or; PAVEMENTS I000 1 1 ' T Thou b: the Ruin} $3.5. WCHIGAN STATE COLLEGE Edward Bergman “ I942 ,,,,, ‘‘‘‘‘‘‘ ....... .......... i “1”le IIII {HHIHINNTWTIIIIHWW ssssss 1 31298 00836 6282_ Treatment to Becrease or Prevent Skidding on Favements A Thesis Submitted to The Faculty of VICHIGAE STAT? 0371?“? of AGRICUEWMRE AVD A“fiLIED SCITUC7 Edward Bergman Candidate for the Degree of Bachelor of Science June 1942 AC T—ff’! ?- "'B.‘ 2".) {P 7 3‘3 T I Wish to extend my thanks to all those who have aided me in prepar- ing this paper. ?oet of all I thank Frofeeeor Allen, *rofeeeor Rothgery, and “r. Coeens, all of the Civil Engineering deaartment for their ad- vice and assistance. 143080 In the field of highway engineering there has been great development in technique and practice from the standpoint of both convenience and safety; but one phase of the safety side has been over-looked, that of skidding. It is the author's belief that this paper is the only work of its kind that covers some theory, method of test- ing, and prevention of skidding on pavements. So far as detail is concerned the paper looks this quality; but in essence it outlines a survey of the problem. Originally it was the author's intention to deal sole- ly with treatment to decrease skidding on ice covered pavements, but this problem from a practical viewpoint was wholly e maintainence problem that did not offer any field for diversion. Instead a survey of skidding on pavements under all Conditions was chosen and numerous scraps of material found in reference sources were acc~ umulated and compiled under the this Of this thesis A lack of equipment did not enable the author to conduct any personal exocriments but from the information obtained it is his belief that some worthy conclusions and results were obtained. ‘ Edward Bergman Fichige State College June 1942 Treatment to Decr;sse or Frevent Introduction Skiiding is a thou tut that is not borne in mind by the designers of roads and pavements in states of e aspe- graphical nature like “ionigsn and other states where they do not hive to contend with share cursz, hills and natural obstructions, hit its 1 nor ence is not to ‘1 be overlooked because even here in 'iohisnn treatment to prevent this hazard has proven verv effective. n th (D o ' I . ,1 V . . In, ‘ ,. ‘. . Winter of 1938»? there was a reiuetion of 70w in traffic accidents in the state Eiqhsuy svstem due to ice control \ and surding on strnirhtawsy as Well as hills and curves. ”hat there are many serious occidents caused by skidding is shown by the statistics of tee Travelers Insurance ’4. Company of America. the r figures show that there ere approximately 1,500 persons killed annually and 3L,OGO '2‘? persons injured each year in the United ates by eccir * attributed, directly or indirectly, to skidding on road '0! surfaces that were slippery. hile some of these an Mi ents were no doubt c‘_tused by *3 :orisis drivin” st envesviv speeds, it is reasonable to assure that more drivers ex- ercise extreme caution in winter and et times when the pavement is nrone to be slippery. The psychological eff- ect is an ever present source of discomfort and uneasiness to the motorist even though no acoidt Hit occurs. A rather curious problem arieee when motorists are unduly cautious on curves with greet super-elevation be- cause if these curves are encountered at a epeei lees than that for which they were deeigned, the car may slide sidewiys down the elevation. Thie ie not an impossible case as nus been shown by recorfie beeeuee many of the fnrementicnted accidente occured on curfeeee where there was practicdlly no friction between the tire and pavement. The qualities to be poeeeeeed by 2 road surface that allows travel in a safe and primer manner are few but eee- ential. Th. surface should have eu‘fficient reughneee to provide friction euoigh between tires of the veehicle and the road to provide for safe stertivg, etopwing, and steer- ing of such veewiclee. If a eurfece has theee qualities there should be no skidding when the vechicle is properly operated. Theoretical cone idefiatione. Eefore tests were ac mally conaucted on pavements to measure their ability to resist skidding some theoretica work had been done. Fortlnzt 161! Tue theery was re Start- iated ry the ae1ual 10: 1., an it migh? be well to mention D: the elements of thworetical cane: er-tion. -he emoant of resistanc offered b5 the surface is (D measured b5 its coefficient of frie1icn whic is 1he ratio between the force yarellel to the read an r?;'1ce and anfi the normal force of the tires on the road when ekiéding is im— pending or actuallv takirg place. If the my dding is m» pending the ccefficient is called the 'cefficient cf static 854 kine1ie friction vhen amplied 1r “fires on VMVP"1V1 rur- fecee. Thle fact alcne proves thet nething may he gvined b5 cxnerimertat on using only statie frieiian as has been reported b5 e;me investigators. T111 saint is ueefl in eL~ 7)} vertieeents for same paving watflriflls and offers geod, irug evidence but it shows nothing of & pr c1ieaL v lue. The reasen fer vawiation between the 150 $5553 1% due to the fact that the total frictional resistance is the eum of the fri . n81 resistance between thu two sxzrfucep plus tkze resist;.nae offered by the inteslonking of minufie part- icles of ruaber with euue15 9me11 nrnjectionc on the pave- ment surface. The more rigid particlefi on the surface tend to shear the rubbar in the tire. Tdia uhatufi 11y 033339 when a quick Stop 93033333 akii mart3, whisfi 333 ravayea particlefi of rubber she1rcd from the tire. he fareqniirg discusaion 19 trla whzn the pavefient in flry but 33% thar to the 9‘11".“‘133 4.131.". iBrI‘vn’?tfm't (31.713.3'3'23? occur. fan :.4. wet 1: 15,31... face this 1.3.12 2.7le 9.13.1223 .13 2. 11113113111213 :mi 112113239 it :19: ~ . ' r '. -' . 1 4' . 7- ‘ l.‘ 1 a - 4 1v’_ 3‘ . ' - - r. 1‘ squequad cr Elleefiuu am. from £13 sarjaeu 1t 31-1 flu am “g wil l I-esult. +5. rate the tire from the gurfuce and aki'd If 9 eeds ovnr 25 or YO nile3 yer hcur are used there will be no remnvul of tbe mater and asnnequently no Skid p30- teetinn. “ban this water is tragpsd between the tire and ’ f: ‘1. \‘\ i'a ‘fll Kg res1s.an3e “3013 0.1 9.3rnly. p. H. the surface akii ( Where 333 howwvmr n-ny vur133fl63 affecting ekld reyist~ anae. Vhe skid resiwtarce, cf course, varies from pave- ,-~ ‘ ‘ ' (' " 3 g- , 1 ‘q 6_. In ‘ ‘ C " ment t3 pavement 323 may 3130 or $13 5333 L3vement khan 0990r "oyer 35 Iowa Ctate Callege, halis that there are eleven factors, other than the inherent grapertieg of the alrfaca its 3 f, that affect the skid resistance. Cf these actors, the type of 9'iddi~g~~~tr 1.~ht skiil. siie skié ding, 3r impending skid—-, the angle of inclination in side skH d1 3, tire pressure, caniition of tire, tyye of tire trend, and canditian of brakes; 3133 the tvmp— erature and mois ture of tne D2"onrnt 3.r.d3e ; and the mted ani load, a? e of prime impartunce. Relative to the Davement surfana it may be generally A ‘ ‘ t stated that the coefficients of fr 13ti3n are hi m} er on fine or sandy textured sarfacqe than on the rougher eur- faeee when the airfacee are dry. $3 a smooth surface the tire tends to hug the navenent and to maintain al- most cometawt Contact. 3n roach gavefients this comptint Contact is not so well 3313331333 are the tire te”d3 to clear the pmvenent betweezl the individ111 3r3* weti .3 . On wet pavemente this an .3ta at 19 no loLyer maintained die to t.1e 133 3131f133 film of water. Tine or sandy texm tured pavemente have relatiV3‘y “£33 noeffieierte of friction when dry 33d relatively low noeffi«lente when met, while the coareer surfaces have coefficients inter— mediate in Vilue 1rd practically tne same either wet or dry. .1 I I At (5. _ . 732'?! u I )II ‘11 ‘U ‘JL\‘V of 3 (" 3 1 I 3 4.1 : (‘1 '." 1ffia1 "K '\1 .s 319 l l used to 14? (‘, . '*ioh 1 n‘ _ 7.- 71‘ {1 F3, r930 1'} ~ L 1 ."f r“- I 3 {on e.- ,‘ 1!. . J 3 1|; ()0 4" b 3:11? 9:2”“n 1‘ {3"}. I I J be 0 .3. utively 8 v 3-... oceaen '0 I" - . a," 1 ., . .1z*(141 111.13: 11:; l lr‘“ ‘-D.. l .145 ‘ equ13* the 'nd. 13 ki i of :t ‘3 ? 5 W1 -' “v- \:"‘I_ 2 ~1ja'5f I r b3st the V _.,, 85'3"!" ‘31-: J. in 3 d 115': {fr (i ;-‘ L). . ’5 . .. T“ I \J. I. ~ 1 to}: .L 8 F935;" 1 V out 0'? , t‘ ..=_.. ‘ .tjrfl .d“-~' 1.. I 9 —- ' w " . 1.; ‘ ‘.. t J I L A. 3 t ‘ I § IO. A v! :4 4.». ‘I C alt? lit bod A .. r! 9 f n 41-4 ‘2 Y‘s} poi ~A. \ ‘.. 1 wit? 1 .\L n - Cre 1?? Viv -? 9.1:. Gd in N reuair- ’"rce '1‘» «Wu .(. ul-c- ,1," u -. 7. Test Trailer used by Oregon State Highway Department fi'! '~ .. ~ . ..= .- 3 ~ ,7? . . 1., ',. he lefefrdflnj dxnflnanafes L? a u3Vi$Q décoLoned ax! I .~ 0 .$ w , 3 a s. . -A . ,. u.- . n by ona 3 4.2 allaqn 32. in u V~rr jflflwrufw Ween? 0f 9 “-'fi“ . ‘ 49.23:": 1.1). --) 11 firfle. It a nmigtfi a? W ha? flnfi~ *- .-I Lu . meapnrlhg tainlng ah elliwticfil baring that cha3z@§ «name Tfifif a null 13 oxevfied awn; it. 3?: P1 ‘t i‘+%etnc in wrawnsi- A .. _ - ‘ . jxnzdl to tflda ?d W“; 199 ;;fi rv e,gw*: and revslatinn 331*fierv it 1v pneflifile fio y~2 a ratiq nf the force argliefl as} due r‘wis*inr fnvné. 'I‘T-le n )e-‘ition a: t'la b351,}? "3?) Iouldt0& P991 1 maatev 0 its nonnention ask;n: UlaTG thrutah a flexible flyfir;ulia q IIOSB. ‘ule t (“V «I .. r1 er '4 y. . 32. we 6 .et .1 ,. .4 s 'N 24 t 1" § .0 0—! I) Q >3 v) ‘1 (‘9' L: ; J .3 w § p- o H v 4. L ’1 . v . ., . .9. .. ' . m: .‘ w . - epreaent tie vor;u anerltLHQ chdifiaua. .ue bot udwve 'fila axle was diviied [Uta 031)&vu2%7.2 with u.n.pi 1a.} ,w M‘ ' ‘ Q' 5 I h ‘ ." "‘ L" ' I n ' ' . L . x 0‘. of 1,600 93m¢¢0. .Ja U0mjl7fim§nu3 preqeatél Phign.nt w. the loud, anl ugalrai a dwifarw1‘fivafl lfiai c? 830 DOIW5?. ,. P: , .3 . ,.. . - 1 ‘-. :11: .3 pn-trmq 3m“ Rwy-113'” mm- .— -, 1*», ‘ . -: '. ’_"+- n~ ‘ .w ~ ,rofe §Hn'r.)tnrerg of 10 A» U} Juite .uLLefl» dev I I . c5 '0 - ‘ .‘2 1 '-"'v ".f g" ‘ '¢ . 3 ' - : ~ e1 1 gimzlar trgilor b1. v.tz the .1-..101¢l wr3vi?Lfid ‘.. .,'| . : +1.- " . .. .r .2 , . tn-t «31039. ..a rqoeis to ba tlrnc. 45 rirht 433133 .3 M ..- 4- -P.. -.=1° : .-.1 1:. tn) :‘ciitjrrt‘éf‘m -‘ OJ." uww.lt:.3'{'.-;3_ S’r:;d__.,r All I ‘0 .3 m + ifth PQVIE‘VI‘TJf.‘ 151:3 vmiau-r‘ rm‘1.31:~ds: of g":.-:}:i?::: a 1..-"e" t. far friction using equipfient ag n 3%ove there are certain “Vt ruleg 9r tefitihq. ”85t9 fikfiuli he mad? at a nafibwr 0f differett anthnt n.00ia P3? 13 20, 7O, and 40 mile: he? hfiur. 7t hi? been phaWh hv fé‘tn that at 90091? Pr91t~ er tagn 40 31109 ner hour there in little an reaiahle change in the confficient. A great ammunh number of trials fluvt he made at each Freed to ohfajn a stubilizei :+ be gverage. Of courfie It i? immerative that the 1 .‘ est made over a rerresentative fitrfitoh of the surface in order to pet usable results. $ne test whael of the trail- er should track in line with one of the paths followefl by venhicler travellina the road. . Gneruéxon of the brake and dynamometer have to he handlad by an overdtor in the tominz veehicle who. upon 91;: 1 from the driver thmt the correct Roeed has bean attained, will mat the brake and start tue dynamnni *1 I . ;. U \l‘ J in use. A reneat trial aver the same course Phouli be run with the sqrfdce in 4 "at condition. In this Wdy Ewe u. temperature effect waald be minimized. 0 ‘fi ‘1. “I 4km“ Results of tests on various surfaces. Although not a great deal of recorded material is availiable on the results of friction tests those that have been performed are complete enough to show how diff— erent surfaces behave and their characteristics. Those surfaces tested include portland cement concrete, bitumin- ous, brick, and oil mat. A consideration of each type with statements of its characteristics will follow. Portland cement concrete surfaces: This type of surfaceing is probably the most existcnt type of pove- ment in use today in the United States. Tts standard of quality is very uniform and it is being more widely uscd and more standardized than any other surfacing. From tests conducted on portlcnd cement concrete relative to its skidding properties it was found that when wet it only had a skid resistance equal to that of certain bit- uminous surfaces; but it did have the most consistsnt properties when tested in both the wet and dry state. The method of finishing is an important factor in deter- minine the amount of skid protection. If the surface is finished to a smooth top the cemen paste drawn to the surface forms a smooth, hard layer that allows slipping to take place. mhe finish should bring the sharp sand grains to the surface in order that a gritty pavement top will result. This may be accomplished by using a canvas belt, operated laterally across the pavement at the time of initial set of the concrete. This also breaks p53 up the coating of cement paste tfb t mirht forzn on the sur- face. If this paste is allowed to stay on top of the pove- ment it not only is moderately smooth to begin with, but is polished to a fine finish by the action of tref_ic. If, at the time of finishin 0, excessive manipulation, vibrating, or floatirg is pernitted this results in a sliom oery surface and should be avoided. “ropcr headline of equipment and only a reasonable amount correct broominn and belting will make for a very non~skid surface. The coefficients of friction of concrete surface: range from .4 to .9 for straight skidding and from .5 to .8 for sidewiee skiidin_. The coefficients of dry, rough textured portlend cement concrete pavements range from .8 to 1.0 for straight skidding and from .9 to l.0 for sidewise skiddirg. A Go mperison of friction coefficients when the nave- ment is slightly met and when it is dry show a greater variation as to range on the drv p vement to in on the net. This effect of moisture on the . even.cn t as previously stet— ed is substantiated by the tests. It shows that the frict— ion coe effi cients arranced thcnselves directly as the course- ness of the surface texture; an inverse relationship existed when dry. Bituminous pave: ents: These pave rents exibited s more wide range of coeffic iento than any other surfioe tested. ”here the coefficients were low they were very much so. rThis state of condition is very bed because once the motorist is subject to this slippery surface he is prone to believe that all such surficee are just as bad. This is espec- ially true when bituninous pevenents are wet. n"'h‘izt this contention is not altogether false was substantiated by test, as some of the pavements tested were dangerously' slippery when Wet. Eut in another res ect this contention carries no truth because on some of the surfaces tested the coefficients of friction on wet pavement were substant- ially higher than on any other type of pavement teeted. Professor Uoger as well aha many other engineers believe that it is possible to build a bituminous roe that would be as skid prodf as any road in use today. Of our leteet bituminous surfaces built in the United States most of them are relatively skid proof. The reaeon for skidding on theee surfaces is that a layer of excess bituminous material had been present on the surface. This may have been caused by the use of too C5 much material or a too slow curing asphalt. Those eve~ ments tested that had the greatest resietance to skifid~ ing were the ones that were covered with sharp, herd rand or finely crxshed rock that wee bonded in place by the bituminous material acting as a cement. This sandpaper like finish offered high resistance to skidding. The friction coefficients for high type surfaces of an asphaltic nature when in a wet condition were higher than that obtained on any other surface tested. Very low coefficients were encountered on penetration mace am when wet, especially if a soft seal coat was need in its top. From data collected on the eurfanee teeted 1t wa- shown that there was a higher coefficient on those sur- faces that had a greater hardness than thoee that were Brick pavements: Tests on brick pavemente vere carried on exclusively by “rofeeeor ”oyer fine the test regulte showed that brink has a coefficient (as a whole) slight— ly less than that of portland cement concrete. The mod~ ern paving brick of today is quite skid reeistant. This is due to new manufacturing methods. Deuaired, vertical fiber, and lagged brioke have a finish that will stand up and is very gritty in nature. WitHcheoe properties aha proper installation uning a hard filler the reeultant pavement will he very safe. 011 mat surfaces: ?heee surfaces are different from bituminous maeadame 1n thickneee only. In the oil mat surface the heavy eurfaae and base is omitted. The friot~ ion coefficients of theee surfaces are eporoxinately the same as those of bituminous EHC&3BM except that they are more prooe to bleeding and consequentlv are more slippery 'A. as they grow old. Treatment t-D grevent or aeoreeee ekidiieg: t 18 not p ocal.le that the r0339 in the Waited Qtetee tefiev vi} 1 he rtel see by new reads that are of a Mki ree- ietaizt natire but that many of the d.h5croua ages can be improved by tr citreet er maint irence ie eonethi 2r thei can be anticipatei. Proteeeor R.A. Voyer of the Iowa Engineer- ing preriment static on perfor1°i teets on vari one pave- ments and prlvei that any surface can be maie virtually skid resistant with traa+melt. $3 ehcwed too that by pro- per maintainance the effect? 01 encw, ice, and mud can be controlled ta make far safe driving. The epee ei factar is ion. This has far flung effects because on wet eeracee at 40 miles per hour the friction aveiliable is onlv l/4 to 1/5 as great c9 at 10 miles per hour. These surfaces might be he tore safe than if ice coverei r0319 if they ('9' offer little resistance when we . The correctinn of this prollem of treating or re— surfacing a pavement to make it skid resistant is one of a relatively simple but costly nature. It old pave- mente are to be r.owz faced the pribe regiie its is to ]_av a coverihg that his a fine ehiro text ere. In cozn< rete thie miv be cocc.cli.1ed by t.e finishing eeerntion. In ‘- bitumino -ne c verinz it is necessary to control the type of cement, the quality of the exeregvte, and most of all the means of construction. The azrv‘t of tar, cat-back, or whatever mi:rht be noel must be hard, of low hemetretion, and so anplied that it does not com 9 t3 the eurrface due to wear or heat free the sun. A more cemnlete deecristian of the ex1ct means of aecomnlishinn t“ie end "ill be diem ~sed later. Probablv the most dangeroue cc nnditlcn of a read ie when it is covered with mud, snow, er ice. It make? no difference 89 to how the rec id mav be CJnC ructcd, thcee elements render it unsafe. Central cf the menace caueca by these factnre is clearly & maintainsnce problem and methods of its treatment shall new be pat forth. The first rule in caring far a ccnditicn where ice or snow is to he removed is prcmntneee. If ice is allowed te form, or sleet nernitted to pile an the frictional ree~ ietance will only be about 1/5 that nrovided by a concrete surface. If send or cindere are applied at the time which freezing begins, which is near the freezinp temperature, the frictional reeietznce may be raised 8 or 4 timee that of the icy surface. When these abrasives are applied at a relatively low tenecrature hey do net become embedied in the in cc and the result& Lt actiws: cf mind and traffic may result in their removal from th e exrfac e. If temperatures drop suddenly, or sleet falls making it imnoeeible to treat the pavement at high temperatures, the abrasives may be heated or mixed with ca alcium chloride to provide the sane effect as application at a higher temperature. Direct app- lication of rock salt or nalciun cflor ide to the ice often tiznee result 9 in detrimental effects to the pavement surfac in teat it Will Gama? sealing of cenerefe or unrmeellin, of a bitumineue ewrfaee. It is eLaLAed by the Wild‘ ?b~ urere hf caleiun ehl rifle that the 30311;; nf the age- 01".,” 1.3 not flue to the 9.7.3.11; but 03753011.:9’ the fe'rfnatien of email particles 0f ice in the peeve? suefeee, the fine expev%in3 and breaking the Generate. “It nevefifvs e”? {b P a ("P b «l I \L '1 it is rec m1en ed that inetezfl of ueing any salt, y or mixed with gene or einiern, that the abras- ives be wildly heated enfl emailed in J.1ie manner. $hie But that treatment of abrasi r,s 19 effective was eenw e‘usively ssown in tan a nor auo+ ed by t‘e Iewa State righ- way Denartment in teetq made at Fort Badge, Iowa. The re- Dort at ates that "all dry ahraeivee not treated with «al- ciun chloride rreved to he ineffe'tive and were eaeily brushed off the reed b ":4 (“P ”3' ”D (+- b- "1 6 :1 m ¢* 1;) ,4. L3“ CD rs r... N ‘ D D *5 the abrasives there was no difference in their exid reeee- tanee when in fihe untreatefi state; but then treated with eeleiun chlsriue the coarse “inflere were 42% more efficient rue for sarC r4- '3 (D 0 J 3 I! 3 g...» 5:4 1+ than the mnteeetei Cinders except that fhe betterment was ?l{. The use of oalaium chloride in eeeneetion with abree- lvee 19 for two pureose9° to eebei the 93rd or cindere in the lee, enfi to keee stoeL—pilee e? abraeive material in a eondtti on w1ere they will th ?rc:7e up. The age of stock~jilee of abrasive material is an efficiency measure ‘ . " - l ' 0 r y ' a g“. '. r ' ~ I . I" — , . ' . - . r. h. ', t0 fat-311.1 313,43 .7"! '31"? I’ufi'ili :‘- )VS‘-i.s‘.13_-I;‘ "up ’EX; " ‘?.(?1‘i"‘~1 f‘l‘am 9.8311": (“1 (f 9 {11745 ?’1 ‘5’ u 3." "' '1" .3 5‘- i.‘.-""' ”’31 3“ .1 .‘7 '. -' f (‘3 X "V 5.1"”? V‘ .3" (“3‘ {‘3 «5' $3.. 7‘15? . p ‘N‘ f ‘_ ..".; __‘_.._ ‘1‘ ' w .‘,-7\' ..‘ ‘.’ , ‘ 1"- _, 1 ' ,_ - use .4 (rxLaiu.qu;;uJA(u3 ;& .ya.ls~u (2 er is») n=9 rd?ih51t up \ _.1 J. . .‘4 .. A 5°... 1. a . . , V.— 4: a 0.x are fuf trem.nent era =rx-*.-° n£r4u~e a? it: =1L1m ' ' ‘ " r1 ‘1 u “- V I ' s u 2 .. ‘ ' arqqze :33.» j :4 “pi; §. U._liloi‘3-fi ,‘1’ I; J .' I\( $3.0“d “‘rj 9- 1") , '..'t'- ;’“‘1 %i '.1.511 ‘ L ”1‘ ‘-‘ 1‘ r! '. *‘3 "‘1 l ? """: “~ :3:*'- :7 3"r: 'fl) " i‘: t'? - o *I. ~ ' l‘ ‘a'- ; + - . V "‘ ‘ , ‘ .- 9. '-|_ v .53 1'... ““11": T1) 1.,L‘.);D.3‘[1)T‘I . . )"'” QI‘LE. "1.13-1. : j. 1...! .‘n‘Lhym ' a”, ' -' ‘7'. u. .9 IV" FEAT. ‘ . "“r”,,, ;\ L‘ 1 :L' ‘3! 1 1’16 buL-J‘J ’1‘“ l“ ‘1 ‘o VLLLG- 1”? \J’-1L~’ i. -9 "’ 5.31? L L4,). .3542, salt. : I "’ ' ‘ " s I . v. ‘ c... .v . q . . 0 .~ 49 t3 the t,-: of eerauive .e a~e fLerc are war} thfib "J I ’- g '3 I --\ I mb i- ‘ k . warn-Q r . n - i ‘ . - ‘ have been HSel ‘iC1 fi:c3ufie. -de 339: t? v‘fily neei any”: ivee are eififiere, fine ezni elk”. ere, *hshefl exri, “,9h 1 MD ‘- v. v‘ 4 1 1 g y m; 1 i J. .1 as Fixts. hG 0P. .rue;1n«L e *v€;-te in «n 'n3C1 toes mat .- -- at - ...1- + wan! -.‘ -..9-, . 2n . we» '~. p;_1‘J£3T1358 13‘ LL f !.)T....+:.r pr», ' J:- Am: 1 «It; ‘ ~ ’33 *3 t .0 H t. 1.0 . . ¢ , -’- - ~ on ‘0' -‘ 1 ' n' . ‘ ‘ ' I " "o a”. '2 '. "‘ ' I '9 “"5 ' €?‘1.V.I?)r',h 15139“ t’..‘ T’uL]. U." E): V‘Ilt... ‘- f'.=."..‘.". ."‘ {P'l} -?'/1: ‘1' = 1 1 - “'4 3' b- ' J, _ 7," .9 ._ 'I. A . k . .. ,. ‘ '_ ‘ .v. ,. . ‘.1 I. E‘l ,1:1 ‘1‘ ‘1'. r t r q n ‘ (‘1 {w '3 ' -) ifiq 3. f- i \‘x I.) a“ I {3‘ t i) I ‘ 2. I, r (V ‘ a ; y l ‘1 i? ‘ " iJ - 1‘ j. :1 i “ ' :r‘ f’ g . .._ in7:e 1 "*0 eheu“" in be a difieew it ‘~0 irwvelinw ”14‘12 H *‘b :3 H I :1 L?) R Li ‘5 2?: ' J \D d that? PTIO‘11.i be few) 91”.". :13)” ini‘arfeiw : ‘ 1 ' ' ' P . fi . l. .‘ I g t . p 4. ' . .. .. .. . . t . .-< I: r . -. 9 a. J - ‘ - -v . 1 A w. - - r2,- . J) ‘ v. . _. w is. V.- m . 1 .g (E f‘e.‘.‘ {f- 11,?! '4' ; 1‘1. ' J..,'.'L1. “i- f‘fi'j I) \.-"1' ' ~"V ": .f“._1 L':_ \‘o . "Hi”? .1 "W r "1 .‘ _‘-‘ L4! (3‘ ' l' . ’ ‘3 ' 1L0 , " ' .' ' '-." ‘.~". " ' ‘. '. -4~ , - -- _ ‘ 'w Lhe prev-9,223.1, 0... PPM. on 3 DAY}: Lug-C 5%! J”! 1.13.):‘tann .- w e .. '1‘ l-L-rw “4‘ -=.,.-3:».~.-, ~‘s.',4...._‘ itaj'n innuxeifu m *1“ ( ‘ hunt '2...“ m .u. 9». am: 1219'. :1_z.m1\:1‘a..’»’l 0,. r) '74» .4- " »-.I , . ’. '-L exr2r him! J“- *L- t: . .i'v.‘ ;,€? 9r: r1 1 *c“eL~\)f 1:L,, ;.$! t1) 109. -II CD t111-)'-1€-):'1 anee to ekiiaizn; We cenfiitione cannot be any I‘Ei‘tt? Lugr'nd't}; tiff-3 . I + .v: ' 9r." '~' *3 ('1 ' (‘1 n llyh‘t ILULRD.) J. b -.'-.’ .fi I‘ “ s \ g, 1.10 {3} J :J 11.3, it necseeery on h1119, ari on eurv {‘5 Hi. The Q Hal mainte of 'ifo‘f via. 0‘ 0' . ’1‘? up» 1}»‘.' :_ O Pn\h auen e Leg “313 greeter genlrt- 3- ~'~ »- ~.- :- .- .y“ - a“. a ui‘u’w‘ Of rim mlufmoelle anger nor-3t P1‘€ thfit 168 l” fie“ pr:;rnt’ nr it pnew. The :54rinq effee“ a? SAW? icult t3 ” Ff1;*uiwh ”ran lee Qae19 sand uni elefie“r ;t interraetinne, 58 ee seen 7e tbe snow became: pagk~ inance way epar men a u J a? . rem "fiVel at the gene time the stern starts Lee to n~ntinue it until the Wonim- 14:15: weaned. A skidiluv “rublen tFHt Is rat rarely tWeugnt of is the one v-z’a :1“: 22.1.1. Sets 35: the 9711:»)qu ”31611191, but 221-13. {m a pevemenfi o~netltuea a enrisan hazerfl in wet weather. The 7111-". that bfi‘idffic" E'?‘f-‘3tt.:1’°Cd on T'e?a‘~.’c?;:;‘*nt;3 1191.12.13.31 (”Wear Sham lere ferm drivee, or fieli problee is eidple ani gravel cautinas are a and x. ,3 4* . .. .1 ' , A . ~ -. tee road, er»m mlufiy side TUJUH, A ”x. _, - . 1: entfd"Cufi. -he tr:Jtnent of tOLF r \ ¢ ‘. ' r. w: 'z " -~ . ~ . 1 n. Y Fadflll be & 43:»L LrQCfliQLDQ if pelied to tie mudiy partiona it @111 1. hold it in place. I brief sawmlry of what eeve u. stguce as to central skifliing in :zlatian to the tree? of suffices 1‘ed new and their mlixtfinlnee preeti¢.s eight be of intereet. Venees: 1 eligfiilfi differwnu unp“oaew to the ekidilrp u‘o- b1 m has been tekee b? feneu”. 1e; fire investigating means of eliminu‘inr fine oil strumke Ofldfiéfi by drippinge from Clrs at t;e smarter oointe of roads. It has been found thet ‘. .fu'fi I «7" | " 1 “f. " ‘ _ 1 3...: . v ._ "‘fi I)“; “.f':‘ 3(1rr'f‘. 4b 11‘ J! ' ‘ 11~ (‘(}r Y?{ ,dr.‘.. ., “f 4.4.3 ’1“; 0 O "_ }: ix “om ’ ‘72! ‘4 Hf? ‘1‘ 6). ion ?rate I . ”(703?! . ( _ I. ‘ I J '. .&n~ \ «.1 \> 1 ( '1 :13;"‘ \. \'. . 3(D‘Tfi... ( 10‘?) r‘ 'yc'q" 3}".1 " v .' =.‘\,- ‘l \ luiPG road C!» 5?! 1‘}. 1 -Au.‘ 'vw pave- i Q non-wri -1 I ’s in C '1.” A... h i r: i.“ 'v-ul. '57! :T'V. ' I w r- .“~ ..' v ,1 \L 4 Ayah-gr { ‘5: 2 LH.‘ u. L. . 9'» -11'3 Ff". ralt 31 "4 0“ ‘.~‘r “T.ré!* an I 2 of cut~ a}? . .p'u 1 l" 4 .1114. I- 0 J- -n, .L ‘J t' \ qu 'A. . Hi? I; .y. 3 Ir ‘...:..l 4.. 1'" Q '1- if} 11 :3. t if} L} utely appliei at a rate .1. 11‘ imme< A Coqerinq of 9199 Wu? tha. of 20 to 22 pounds per square yard and no broominq woo per~ -.—1 mitted. This too was then rolled lightly fit; a 5 ton roll— er and no traffic permitted to travel on the Surface for 72 hours. The excellent regulto ohtained seem to indicate that the time the traffia W3? kept off v09 well worth the trouble because +his allowod the volitile materialg in the asohalt binder to emcape. Tinter waintainnnoo in Virgiria covniqts of soreading Cinders, coarse stone dust, and sand with an admixture of calcium chloride or Pfllt at a rFte of about 75 to 100 pounés to the ton. Texas: Peciuse of the heavy rain? in this state the oreoomco of water on the purfaae of roads travelled a high gooedn hag been the sourco of a skidding menace that no? been tak- en care of by the method of conPtruotion of their highwayc. when fini9hinz concrete roado it 19 required that they be belted at the tint of initial Fet in order that the sharp sand particles be brought to the surface and rmall lateral grooven be left in the concrete to facilitate rapifl runoff of the water. This ha? produced a very highly non-skid ourface. Colorado: The State Highway Department of Colorado has ach- ieved a nonnekid surface in their bituvinouo road mix pave~ ments. They attribute their 9qoneav to control of the amount of asphalt used. 3y using only enouwh of this to the eooent- ial biniinq Qualities needed, no bleeding Will reoult. A seal meat is plfioed over this main course containing a cover atone which provides a gri’ty surface thzt in very re?ist- control it shore that there is game variation in the we‘- .1 9 L hoes of courtruc inr pavemerfc; but there 19 suite convict- ant praatice in mairtainan03. .DA .44 fl :1. .) ,. .1" L ., C l"; :1. "7 6' N 1.7.} . (-0. t ‘0‘” a— fi 5: § ._.¢' :1 -, - .0 '5'.)A.L. . I ,-.v -1 ‘1 'agl J) "‘ ‘ "‘I ‘ ' 5 ’d‘. d 4.. -.i .l— , Y ‘ ‘ 3’ 4. \‘I J I ’. w... ‘ 14.7).5vnm ‘, 'l- \--‘- *nfi -.. ."I .3 U J- J‘. 1 . . 1., Raga r. i- " b 3 g. .~..J. 5 ‘..- - I -\ - «u: J‘oir‘ ..._1 .4 " 1‘ " 1 .9 l? A- gate '5." . L] ' V 2 J ' 1' a, ._-_".. x ‘3“ . .~ rs: «wacfi W ‘rmrvx rut: 1mm .rv~'-'v=”-."*wrr"i “”3” a” 1" A é t '2 1.! 4...“) ' .2112.) -’ TD- & .." r , ".1 '~~-'LA‘ 1.! 1 lg “2".1-) -$. “ .'~ “(7."?! Y‘W)"qviv% "’in I I", ’37“ H‘ “.r '3" "9.1.1711: ("‘7 3"“ ' i" ‘ ’1 3' L 1 Cu" 211‘s! 9-.) '~ " A . 1;.“ ‘_-'.." '_ 3", 43'“ “C 12‘ -4 or game frw&v of irdivifimalfi f0 knaw about the 91id« resintant Phdfiafitfirifitinn of a oarfain pavement aqrfafie at same jarfinullr time. “an to a lack of equinwent or time it wag not possihln t« he nrliqhteuefi unwn thfi sub» jeet, hvfi’IQW‘ér, “"1111 Eng awfulhlrl nemwed mam)" tines to a acuity, 0? email tnwn road nnmmisninn but due to the expanae it man not nnwfiihle to nhtain the infn‘mation. q I Th9 anthfir vial? finW “T9¥°nv a {fig '1‘) J) methnfi fnr ObtliV- ing tfiia 1n9arwation in hogan that it Wigdt offer a Sizveation to cowenna tn carry on the mark. Wirat fihe prnient nhnuli b» minded in fhe hands of some ra?e1rn* bviri 910% aa the Vurmxu of “ufilia *aan in orler that it might be 3*?9at1valr nanaled. ”he Gutv of thia owranizatinn would b8 to ran teat triala on has various 91r93aeg with eqminnent no nvfivinuqu degqrihed, Having this infnrnntinn pertainent tn the tyne of snrfame, its methai 3? nonatrqction, constituents, finiah, an& aoeffiaiantq qf friction at varionn P§eeds on hath vet and dry sirfdces; it mauld than bn required to nhotogranh the EJPPIPF by name stanflariifiefl mofnnfi. This cauld be ‘3 best anccmplichod by taking a 5 fig whotn of the Davao ment with a ruler lying on the sarfaae ani the fill 12 130m89 exteflfiirg 0V?" fhe Whole 1en~th ff the nictnre. ‘- _ - K. .. 4... ..:.1. 1.. ..n. ... .1- . , 7,..1: vhf-.8 piCde‘i‘ 5'..LL’}i 111:6 iIZALilflnlsl-z'.L(-)IL (3011(422‘11il‘133, the p&vement : 0 q a 1 ' w“ -L 'r . '. n" . I” r g LVG’ (‘0'. {;-.0CJ.K£ 10 (DEL OJ. 5. U9 ‘ .‘l “(?+ 3115...)-11C'f3 (1‘1’-‘}.i 9165' a "i cl“ 223' If a coupfieu. series on esn fe+nle° v~re taken and Q Q ‘ ‘ ‘ ‘ a " 1 5 fl' . i I‘ 1: + 5 ‘-‘v ‘r . ' ‘- 5‘ 1 -- ~;. Cumgil'fl in some ozder;g aura and h»?ullU&Cei yo «1; read r q-\‘ o ‘ _‘~.:. -~ - .. 7" ‘ ’.. ' I‘ "'i W n -"""" 5.381; ' 3.83 03.“ (Mulch! .!:£ “-7 L'v",‘C.-’.L'.. li-w‘b? :1. UNBc-J»? 0.. (ML-ids.) 1313’ .J U l th~;;t "$4144; be "" ‘- fl I ' ,'- .j ,.n‘ ~ J. w. - $1- 3 7'. } ‘- Ulgehll‘ I» a-‘V (-311 VIB~J '1‘; '- if}? £3016: F. ¢.I'-".I."u LL...“-‘. 0 a h“ ’1 -. .._ , w 1 - 4. .9. , v... 4 . N. .. 1-. .o .3. ”:81: ‘-"‘ ”L41: ‘0‘} yo t&'~.‘i.€’ :1 .._.~ 2-1" VAU‘igléfl ,-‘I3. (L; (.31 ' -‘ v ' :4". ~' r 'H ‘ . . " -\ ‘ . . - -, — .- .... §- 4- K. --‘ _ W Pwvenuut 1n 143?L-mhp hniarmc as TUwaP 1” no tfie 10%u1‘- - ’2 r3 » ' ‘ ‘ fl ’ . w .1 n ' ‘9 . . ‘ A /_ .u .0 c 3 me mean»; of cnmmn'i» on W‘331Lxx be t» 1* 11'». u t 4 r. tufiil‘ up .. o .— ‘ A . '~ 4.. 'v ._ .1 3' . . ~. ’ ‘3‘ ,- ‘- w ¢ u‘. ,.. . paweupjt ana “A? gcogcy cl&33, L.e. eitwef Gfihuffiuu, U1t~ n” "0 “ 3’ $“ 'fi‘:’ ‘ ‘ .34" v ’ " 1' .‘ ‘ 9 ~' ternu;u3, 01].:a4u, «ago. .hggg ndA:Lf i».ua taerx‘the gxn;to- . . > ' . 'fi .‘ ‘., . g. L, '.| , .~ u . .-\ a . ’ h 3 . 3 _ #3423 UudLi we Javaneu &;1*n:L WLL Ln— j‘tLlfinq *1 tuna 'l‘F‘" '9 ‘ 3" "‘w‘ " a-a -4*¢'!"‘ x-‘w" r 4‘» ['1 a " n "" I: :11.” ( A.” _, \AJ. 7 U ,Ld I L 4 .U. » Il'vkl .. u 1 3'1) .L?‘ 311’ 3‘; J I?“ . 3 4-9 . ,L 4.- . -, 1: 1. +9 ,. cJL(_-1.1'-L<‘:ter;’:"“.593 0; $18 “101.11.:1JJ. .8 ”18 S-‘LMG. “ . . V. . . ,. , , _ ,, .. y . 5', “ bx- I ~. G. . - ~ 1'1]. tit.) £3311 )Uilu'lr'h 9-1533?! c??3 {time 3.1017017th $15". CL~P~11 g) vizich are sfuwn 1'1 “their hlelefirz €71;_::1~;n321€-‘r+."‘-..:~._13 ’“r-‘cl‘r‘d‘rt' I r.- ~I‘ " ‘ A. 1 ‘,.~ ' 4‘- ‘? a --‘\ A, vard .ibh ape , tn;?u buifl; taben ‘reg tne arexon rnport. Photograph of Concrete on College Drive on M.S.C. 1. . ‘rx \1 ~\‘ \ Coefficient .6 ‘\~ ‘~—~ Of ‘\\ Friction \\“ .4 N“ '- Dry 10 20 30 4O 50 Niles per Hour "h>tograph of ?enetratian Haaadam , Jaflt Lansing, Winn. 1.0 .8 1 1 '6 boelfieient of Friction .4 .2 Dry 10 20 no 40 50 "" We“ @1195 per Hour rflryo 1'“. 1‘. "v" V‘" 13.1.; hpb‘ 17‘ . 4.“ , 1.1 ...-u -: 3.; 1. 11692.21“ 1.3 mm 1.11.1.8-4118 ('7 z. .4- —. - ? 0‘ w :‘a ‘ '5 t. 2 I, r " - I ' _.V—"'3'7" A “" ‘ L ~~¢K1L’.""L'Ut:.1.bw" u 5!! I.» 11110;“? mafia "as. '3 )1. JREQW‘J - Mi Kim ".1 It 1“ .. 5—. . _. .1 1411163178.: 9 «.v 4.» .w 1.; ..1 . 1n n. 1241:1311 L... in.Lglla'-'.sj injdL’JH 5136.1"; , 'uaeeiinga. .1 fl“-,- 4 ,-- 5;. "‘ qt , 51: "it“, ', V'thr’t i. T.‘ 'I‘ ' ri\} '1! 11 1,151,! U1 u 1.1.3.1 113 «'11 1.).."111 . AS 1 M R 1 8 arm ”mum- r‘ r “"3"?” me,_n..n.-.~1.1 . Hui .. ., . .‘V? 'c ,. 0 ; ”a1uiim Vn1arlda u11buiu1 ". -. .._,:., ., 1.545684. LB 5‘3 Ro¢da and B11dg es. .“,_ .-. ,. -.._..' I“. .., 'J . . | atlfiifleerllg 21.1111 'Julltl'cls t 1300 N10 ' ~ ' -. T‘T ... ""' . . 4 Edgineaclag Jews «eeoru. .. 4... 1‘".- «A - Ruaua and load Vans ractlon. grumgrxxxltofie ¢wn1r2a . R ‘ ~ +1 an": 0d; :5 («11:1 0 v.1 \o Lon. .' .0 _ 9w 7:2. ' b, - g 3.41615. ”113111001‘1116. ‘~ 3 iaoxa Tran r".‘-" ‘ 4 r)“.'- F"‘ “.-"""?"- ‘n' ' d‘l hlt‘tzsg JJI‘OJL'. ‘11.? lJ' 11‘ . ..IJ-o‘15i ". .{3fl ‘jz’tix’ 9.1.1111 hLi‘llA-J., ..L ‘7".XEO 7.! . tr? 1.4!. ”7,3“ 5 ‘ 7 _ ’ 0‘ I; Sl‘ Lunlafu, 411L111}? LL. ’31-'51 £37101)“ AkL}"-'.LL1,'€.’.J .1: -25.:‘J..l 18741 S -- Hw—u- ‘m , n1 9 Aunlwwbfld r1. 4.21:: ~‘-~_ “ ~ ’fl'a .‘ f _- ‘ ." ,-. .'~. ‘. H. ‘- '. . 5. 9:! -‘ I 3 ng l. g_-.' ~n’ u. ,‘w- ‘l . 1940 7. \l WWIHII‘HHI IHHHHWI N M ‘ 29300836628 I, °