1 00:00:01,840 --> 00:00:07,920 Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey Brainstuff Lauren 2 00:00:07,960 --> 00:00:11,959 Speaker 1: vogelbom Here. If you've spent a good amount of time 3 00:00:12,039 --> 00:00:15,840 Speaker 1: driving around the United States, especially in rural areas, you've 4 00:00:15,840 --> 00:00:20,439 Speaker 1: probably noticed those messy looking black squiggles that cut across 5 00:00:20,520 --> 00:00:24,480 Speaker 1: asphalt paved road surfaces and what looks like a paphazard 6 00:00:24,520 --> 00:00:28,640 Speaker 1: fashion at best. But arest assured they're not the wasteful 7 00:00:28,720 --> 00:00:32,640 Speaker 1: result of some sloppy tarwork, nor drizzles from your local 8 00:00:32,800 --> 00:00:38,120 Speaker 1: tar tankred transport. Instead, what you're noticing is crack ceiling. 9 00:00:38,800 --> 00:00:42,360 Speaker 1: It's a time honored technique for remedying damaged road surfaces 10 00:00:42,520 --> 00:00:46,199 Speaker 1: without inflicting more pain upon taxpayers by tearing up and 11 00:00:46,320 --> 00:00:50,040 Speaker 1: repaving the entire road and disrupting traffic while that work 12 00:00:50,120 --> 00:00:55,720 Speaker 1: is done. Asphalt is the sticky, binding liquid that sets 13 00:00:55,760 --> 00:00:59,280 Speaker 1: around the rocks and stuff that make up our road pavement. 14 00:01:00,200 --> 00:01:04,280 Speaker 1: That pavement can take a pounding from heavy traffic, for example, 15 00:01:04,640 --> 00:01:08,200 Speaker 1: or from the expansion and contraction that happens during seasonal 16 00:01:08,280 --> 00:01:12,560 Speaker 1: changes in temperature. Cracks develop when stress builds up the 17 00:01:12,560 --> 00:01:16,000 Speaker 1: surface layer of the pavement that exceeds its tensile strength. 18 00:01:16,880 --> 00:01:20,200 Speaker 1: Design and construction flaws such as an adequate drainage for 19 00:01:20,280 --> 00:01:23,760 Speaker 1: rainfall or a weak base underneath the road, can also 20 00:01:23,840 --> 00:01:28,440 Speaker 1: cause the surface to fail. Cracks are insidious because once 21 00:01:28,480 --> 00:01:31,680 Speaker 1: they appear, water can get in not just the cracks 22 00:01:31,760 --> 00:01:34,039 Speaker 1: but the base of the road and cause lots more 23 00:01:34,120 --> 00:01:39,240 Speaker 1: damage as it expands and contracts with the temperature. In 24 00:01:39,319 --> 00:01:43,080 Speaker 1: the arcane, highly technical world of road maintenance, there are 25 00:01:43,160 --> 00:01:46,560 Speaker 1: actually a lot of different types of cracking to contend with. 26 00:01:47,480 --> 00:01:50,840 Speaker 1: One of the most unsightly is fatigue cracking, a which 27 00:01:50,840 --> 00:01:55,000 Speaker 1: turns the highway into something resembling an alligator's hide and 28 00:01:55,080 --> 00:01:59,480 Speaker 1: which usually requires an extensive repair job. Another type of damage, 29 00:01:59,520 --> 00:02:03,600 Speaker 1: reflection cracking, results from movement between the road's asphalt and 30 00:02:03,720 --> 00:02:08,240 Speaker 1: concrete layers and looks more like a jagged gash. There's 31 00:02:08,280 --> 00:02:12,200 Speaker 1: also edge cracking, in which rows of wavy, curved cracks 32 00:02:12,240 --> 00:02:17,160 Speaker 1: parallel the road shoulder. If you've tried to build a 33 00:02:17,360 --> 00:02:20,160 Speaker 1: nice new road every time that stuff happened, it would 34 00:02:20,160 --> 00:02:26,079 Speaker 1: be prohibitively expensive. In introduction to crack ceiling, a two 35 00:02:26,120 --> 00:02:28,440 Speaker 1: thousand and eight treatise on the subject from the Texas 36 00:02:28,440 --> 00:02:32,160 Speaker 1: Engineering Extension Service at Texas A and M University, the 37 00:02:32,280 --> 00:02:35,799 Speaker 1: experts note to that ceiling cracks is way cheaper, about 38 00:02:35,880 --> 00:02:39,240 Speaker 1: two thousand, five hundred bucks per mile of road compared 39 00:02:39,280 --> 00:02:42,400 Speaker 1: to sixty thousand dollars for putting down an overlay surface, 40 00:02:43,440 --> 00:02:45,720 Speaker 1: though of course two thousand and eight was a while ago. 41 00:02:46,160 --> 00:02:49,799 Speaker 1: In twenty sixteen, the city of Littleton, Colorado, estimated that 42 00:02:49,880 --> 00:02:52,880 Speaker 1: crack ceiling cost about five thousand, five hundred dollars per 43 00:02:52,960 --> 00:02:56,760 Speaker 1: laane mile, while overlaying cost approximately three hundred and twenty 44 00:02:56,880 --> 00:03:01,280 Speaker 1: thousand dollars per laane mile. Trick friends a mile is 45 00:03:01,280 --> 00:03:06,560 Speaker 1: about one point six kilometers. These seals aren't actually made 46 00:03:06,560 --> 00:03:09,639 Speaker 1: of tar these days, it's more likely to be some 47 00:03:09,680 --> 00:03:13,880 Speaker 1: sort of high performance polymer asphalt mix designed to form 48 00:03:13,919 --> 00:03:16,800 Speaker 1: a bond that's flexible enough to move with the road 49 00:03:17,080 --> 00:03:20,520 Speaker 1: and keep the crack from growing. A cruise apply it 50 00:03:20,600 --> 00:03:23,240 Speaker 1: to the fissures with a device that looks vaguely like 51 00:03:23,280 --> 00:03:28,880 Speaker 1: a vacuum hose working in reverse. However, although crack ceiling 52 00:03:29,000 --> 00:03:32,720 Speaker 1: can keep a road from deteriorating further, it doesn't make 53 00:03:32,760 --> 00:03:36,280 Speaker 1: the road any smoother. You might not feel it in 54 00:03:36,320 --> 00:03:40,680 Speaker 1: a smooth riding sedan or suv, but some motorcyclists call 55 00:03:40,720 --> 00:03:44,240 Speaker 1: the patches tar snakes and contends that they cause damage 56 00:03:44,280 --> 00:03:52,600 Speaker 1: to bikes or even accidents. Today's episode is based on 57 00:03:52,640 --> 00:03:55,200 Speaker 1: the article what are those wiggles of tar on the 58 00:03:55,280 --> 00:03:58,160 Speaker 1: road on howstufforks dot com written by Patrick J. Kiger. 59 00:03:58,680 --> 00:04:01,840 Speaker 1: Brainstuff is production by Heart Radio in partnership with HowStuffWorks 60 00:04:01,840 --> 00:04:04,760 Speaker 1: dot Com and is produced by Tyler Klang. Four more 61 00:04:04,800 --> 00:04:08,600 Speaker 1: podcasts from my heart Radio, visit the iHeartRadio app, Apple Podcasts, 62 00:04:08,680 --> 00:04:10,600 Speaker 1: or wherever you listen to your favorite shows.