1 00:00:09,240 --> 00:00:13,380 - [Announcer] Prime coats, curing materials, seal coats, 2 00:00:13,380 --> 00:00:16,680 all are essential to pavement structures statewide. 3 00:00:16,680 --> 00:00:18,600 The Texas Department of Transportation 4 00:00:18,600 --> 00:00:21,060 and the Texas A and M Transportation Institute 5 00:00:21,060 --> 00:00:23,550 investigated when, where, and why 6 00:00:23,550 --> 00:00:26,730 a prime or cure is needed for a pavement layer. 7 00:00:26,730 --> 00:00:30,600 Guidelines were developed from tests in the field and lab 8 00:00:30,600 --> 00:00:33,903 to help determine what would be best for each project. 9 00:00:35,520 --> 00:00:37,200 - It is common to have questions 10 00:00:37,200 --> 00:00:40,740 about the materials required in a pavement structure 11 00:00:40,740 --> 00:00:42,960 that are non-structural layers. 12 00:00:42,960 --> 00:00:45,960 This include prime coats, curing materials, 13 00:00:45,960 --> 00:00:48,180 seal coats, and tack coats. 14 00:00:48,180 --> 00:00:51,000 - The designers and the inspectors, 15 00:00:51,000 --> 00:00:53,280 the people who monitor construction/set up design, 16 00:00:53,280 --> 00:00:54,990 needed to have an understanding 17 00:00:54,990 --> 00:00:58,530 of what these materials were, how they should be paid for, 18 00:00:58,530 --> 00:01:00,270 and when we should use them. 19 00:01:00,270 --> 00:01:02,760 And that's really why we started this 20 00:01:02,760 --> 00:01:05,010 is to have a little bit more education 21 00:01:05,010 --> 00:01:07,980 of what the purpose of this material is. 22 00:01:07,980 --> 00:01:09,420 - [Gisel] The common questions are, 23 00:01:09,420 --> 00:01:11,970 what materials should we use for bonding? 24 00:01:11,970 --> 00:01:12,840 What are the difference 25 00:01:12,840 --> 00:01:15,960 between priming, curing, and sealing? 26 00:01:15,960 --> 00:01:19,050 Although these materials can be sometimes be the same, 27 00:01:19,050 --> 00:01:21,120 their performance may be depending 28 00:01:21,120 --> 00:01:24,240 on the application rates and timing. 29 00:01:24,240 --> 00:01:26,940 - We did surveys with TxDOT districts 30 00:01:26,940 --> 00:01:29,340 to see how they were using these materials, 31 00:01:29,340 --> 00:01:30,930 when they were using it, 32 00:01:30,930 --> 00:01:33,720 and to get their impression of how well it worked. 33 00:01:33,720 --> 00:01:35,400 We visited some projects 34 00:01:35,400 --> 00:01:38,550 and looked at it in place from the construction standpoint, 35 00:01:38,550 --> 00:01:40,530 and we even looked at some products 36 00:01:40,530 --> 00:01:42,930 that weren't traditionally used as prime 37 00:01:42,930 --> 00:01:45,300 to see how they performed. 38 00:01:45,300 --> 00:01:47,520 And then we did an extensive lab study, 39 00:01:47,520 --> 00:01:50,220 where we molded different types of base 40 00:01:50,220 --> 00:01:51,780 that will be used on the roadway 41 00:01:51,780 --> 00:01:54,060 and applied different primes to that 42 00:01:54,060 --> 00:01:57,690 to determine curing time, what the benefits were, 43 00:01:57,690 --> 00:02:02,490 whether it was bonding or moisture control. 44 00:02:02,490 --> 00:02:03,930 - [Gisel] The developed guidance 45 00:02:03,930 --> 00:02:07,350 can assist designers and inspectors to understand 46 00:02:07,350 --> 00:02:10,770 the where, when, and why these materials are used 47 00:02:10,770 --> 00:02:13,890 in new construction and rehabilitation projects. 48 00:02:13,890 --> 00:02:15,480 - [Darlene] It's a benefit because 49 00:02:15,480 --> 00:02:19,290 without the understanding of why we use it, 50 00:02:19,290 --> 00:02:20,520 it could lead to some people 51 00:02:20,520 --> 00:02:22,710 makin' a decision to not use it. 52 00:02:22,710 --> 00:02:26,410 And we found that the benefits of using this product 53 00:02:27,270 --> 00:02:29,880 outweigh the benefits of leaving it out. 54 00:02:29,880 --> 00:02:31,920 So, it's a benefit 55 00:02:31,920 --> 00:02:35,100 in the long-term durability of our pavement structure, 56 00:02:35,100 --> 00:02:36,903 and so we need to continue using it. 57 00:02:37,740 --> 00:02:38,910 - [Announcer] For more information 58 00:02:38,910 --> 00:02:41,340 and to find the publication for this project, 59 00:02:41,340 --> 00:02:43,650 please visit the TxDOT Research Library 60 00:02:43,650 --> 00:02:44,853 at the link shown below.