Superpave: 1999 Survey

<HEAD>Superpave: 1999 Survey</HEAD> <IMG SRC="/images/SP-head.gif" ALT="Superpave"> <TABLE CELLPADDING="13"><TR><TD> <FONT FACE="arial" SIZE="3"><B>1999 Superpave Survey : Segregation, Tender Zone, and Compaction</B></FONT> </TD></TR></TABLE> <TABLE WIDTH="850" BORDER="1"> <TR> <TD WIDTH="45"><B>State</B></FONT></TD> <TD WIDTH="80"><B>Have you had any segregation problems with Superpave (SP) mixes during this construction Season?</B></FONT></TD> <TD WIDTH="80"><B>If yes, Specify type of segregation. (a) End of load, (b) Center line, (c) other, Please specify.</B></FONT></TD> <TD WIDTH="80"><B>How does the extent of the segregation problem compare with non-Superpave mixes?</B></FONT></TD> <TD WIDTH="80"><B>Have you encountered tender zone related problems with Superpave mixes in 1999?</B></FONT></TD> <TD WIDTH="80"><B>Are your tender zone problems related to specific binders? Please specify grade(s).</B></FONT></TD> <TD WIDTH="80"><B>Are your tender zone problems related to specific nominal mix sizes? Please specify mix size(s).</B></FONT></TD> <TD WIDTH="80"><B>Did you encounter problems in obtaining required density with Superpave mixes in 1999?</B></FONT></TD> <TD WIDTH="80"><B>How does the extent of the compaction problem compare with non-Superpave mixes?</B></FONT></TD> <TD WIDTH="125"><B>Have you experienced any other problems with Superpave during this construction season?</B></FONT></TD> </TR> <TR> <TD WIDTH="45">AL</FONT></TD> <TD WIDTH="80">Yes (based on one Superpave project)</FONT></TD> <TD WIDTH="85">End of load</FONT></TD> <TD WIDTH="80">Less than Marshall or Hveem mixes.</FONT></TD> <TD WIDTH="80">Yes, one project</FONT></TD> <TD WIDTH="80">We do not think so.</FONT></TD> <TD WIDTH="80">We do not think so.</FONT></TD> <TD WIDTH="80">Yes, seems to be more of a contractors's related problem than mix, bigger contractors have less of a problem.</FONT></TD> <TD WIDTH="80">Somewhat more than Marshall or Hveem mixes.</FONT></TD> <TD WIDTH="125">Yes, we had a project where the liquid modifier coagulated. As a result, the pavement showed clots of the modifier, which then developed small holes/voids on the pavement surface.</FONT></TD> </TR> <TR> <TD>AK</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>AZ</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load, quarter points (apparently related to slats in the paver)</FONT></TD> <TD>Same</FONT></TD> <TD>One project with possible tender zone issues</FONT></TD> <TD>Did not appear to be binder related</FONT></TD> <TD>Problem mix was 19mm</FONT></TD> <TD>One project had significant problems, appeared to be tender zone/lift thickness related. Some, but not all projects had minor compaction problems</FONT></TD> <TD>Somewhat more</FONT></TD> <TD>Nothing that we did not see with other mixes</FONT></TD> </TR> <TR> <TD>AR</FONT></TD> <TD>An insignificant amount</FONT></TD> <TD>End of load</FONT></TD> <TD>Less than Marshall or Hveem mixes</FONT></TD> <TD>Minimal occurrence</FONT></TD> <TD>Don't believe tender zone is related to asphalt binder grade</FONT></TD> <TD>Have had an occasional problem with tender zone. 12.5mm and 25mm mixes</FONT></TD> <TD>No significant difficulties in achieving % compaction</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>Nothing significant</FONT></TD> </TR> <TR> <TD>CA</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>DOT has not yet used Superpave mix design method</FONT></TD> </TR> <TR> <TD>CO</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>CT</FONT></TD> <TD>No, but too early to tell, two Superpave projects being placed use MTV, use three drop loading method and have ride spec.</FONT></TD> <TD> </FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>Yes</FONT></TD> <TD>No, the conventional thinking is that tender zones have always existed, but become more obvious as mixes become coarser. use only 64-28 except for RAP mixes</FONT></TD> <TD>Initial findings show that the coarser mixes (37.5mm) are easier to compact than the finer mixes (9.5mm)</FONT></TD> <TD>Generally, no</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>We are currently utilizing a level 4 (3-10 M EASL) 12.5mm dense graded which is graded above the restricted zone (similar to conventional ConnDOT mixes) and a level 5 (10-30 M EASL) 12.5mm coarse graded mix which is graded below the restricted zone. Although these two mixes cannot be compared, a common problem with both is VMA of 14 and VFA of 65-75 criteria are not consistently being met.</FONT></TD> </TR> <TR> <TD>DC</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>DC's first project will start sometimes in Spring 2000</FONT></TD> </TR> <TR> <TD>DE</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>FL</FONT></TD> <TD>Yes, seems to be related to bad construction practices than to a Superpave problem</FONT></TD> <TD>End of load</FONT></TD> <TD>Same as with Marshall or Hveem mixes (may be less)</FONT></TD> <TD>Yes</FONT></TD> <TD>Mostly with unmodified 64-22. Fl has done minimal work with other binders</FONT></TD> <TD>9.5, 12.5 and 19mm mixes, all coarse graded, minimal problem with fine graded mixes</FONT></TD> <TD>Yes, this is a big problem</FONT></TD> <TD>More than Marshall or Hveem mixes</FONT></TD> <TD>In Florida, pavement permeability with coarse graded mixes continues to be a serious concern. Meeting minimum VMA requirements with Florida materials is also a problem</FONT></TD> </TR> <TR> <TD>GA</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>HI</FONT></TD> <TD>Yes (based on one Superpave project)</FONT></TD> <TD>End of load (based on one Superpave project)</FONT></TD> <TD>Same as with Marshall mixes</FONT></TD> <TD>No</FONT></TD> <TD>N/A</FONT></TD> <TD>N/A</FONT></TD> <TD>No</FONT></TD> <TD>Less than Hveem</FONT></TD> <TD>No. Hawaii DOT has done only one Superpave project to date and answers are based on that one project only. They have couple other projects scheduled for this coming year</FONT></TD> </TR> <TR> <TD>ID</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>Have not placed any Superpave pavements to date. will be placing some in the year 2000 construction season</FONT></TD> </TR> <TR> <TD>IL</FONT></TD> <TD>Yes, producers who had problems with non-Superpave mixes are experiencing the same problems w. Superpave mixes</FONT></TD> <TD>End of load</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>Yes, related to binder changes</FONT></TD> <TD>PG64-22 did not set up for rolling during construction, PG58-22 did not set up after construction</FONT></TD> <TD>More on 12.5mm mix</FONT></TD> <TD>Some, due to harshness of mixes</FONT></TD> <TD>Somewhat more than Marshall or Hveem</FONT></TD> <TD>Was unable to achieve VMA based on the recommended Ndesign tables, has developed their own Ndesign tables</FONT></TD> </TR> <TR> <TD>IN</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load, center line, transverse</FONT></TD> <TD>Less than Marshall or Hveem mixes</FONT></TD> <TD>Yes, mostly related to rolling/density issues</FONT></TD> <TD>No, found problems on the entire range of binders including AC20 & AC10, generally not noticeable on the higher grades, i.e. PG64-22, 70-22</FONT></TD> <TD>No, tender zone issues have been found on 25mm base, 19 & 12.5mm intermediate and 12.5mm & 9.5mm surface mixes</FONT></TD> <TD>Yes. We are now specifying lower roller speed & lower amplitudes. This has helped in achieving density on all mixes</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>Minor flushing. Indiana is adjusting to the new AASHTO design tables for 2000 construction projects and has implemented a transition period for contractors to update their mixes to the new requirements</FONT></TD> </TR> <TR> <TD>IA</FONT></TD> <TD>None to report this season</FONT></TD> <TD>End of load in past years</FONT></TD> <TD> </FONT></TD> <TD>None this year</FONT></TD> <TD>N/A</FONT></TD> <TD>N/A</FONT></TD> <TD>None</FONT></TD> <TD> </FONT></TD> <TD>Major problem reported is with getting different gyratory compactor to correlate. Without the correlation QA/QA is questionable</FONT></TD> </TR> <TR> <TD>KS</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load, longitudinal other than at centerline</FONT></TD> <TD>Somewhat more than Marshall or Hveem mixes</FONT></TD> <TD>Yes, on a portion of the mixes</FONT></TD> <TD>No</FONT></TD> <TD>19mm</FONT></TD> <TD>No</FONT></TD> <TD>Somewhat more than Marshall or Hveem mixes</FONT></TD> <TD>We have been able to achieve specification density on all projects. However, our Superpave mixes require additional compactive effort. Kansas has a segregation test that uses a nuclear density gauge to measure uniformity of the mat. The results of the Kansas segregation test shows that segregation is related more to the paver and lay down process than the type of mix (Superpave, Marshall, etc.). Kansas has found that the auger paver does a better job of eliminating segregation on all mixes than a material transfer device. We have a concern about permeability of the 19mm mixes that go below the maximum density line.</FONT></TD> </TR> <TR> <TD>KY</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load, evident for some base course mixtures when MTV is not utilized.</FONT></TD> <TD>Same as with Marshall mixes.</FONT></TD> <TD>Yes, for a few mixes</FONT></TD> <TD>Seems to be evident for PG64-22 mixes, but no real pattern has been identified</FONT></TD> <TD>No, experienced for both surface and base mixes</FONT></TD> <TD>No. but, vibratory rollers have been used for most mixes including surface mixes.</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>Superpave mixtures have behaved similarly to Marshall design mixtures.</FONT></TD> </TR> <TR> <TD>LA</FONT></TD> <TD>No, Although slight segregation has been noticed on 25mm mixes. MTV with remixing capability is required on the final two wearing course lifts.</FONT></TD> <TD>N/A</FONT></TD> <TD>Same as with Marshall mixes.</FONT></TD> <TD>Yes, slight problems only. Both on mixes built through restricted zone and below.</FONT></TD> <TD>Slight tender zone problems have occurred on some mixes with PG 64-22, PG70-22 and PG 76-22</FONT></TD> <TD>Some of the 25mm and 19mm mixes had slight tender zone problems.</FONT></TD> <TD>Projects constructed achieved required 90 PWL based on 92% TMD. Most averaged 93.5% TMD.</FONT></TD> <TD>More than Marshall mixes because of PWL requirement rather than just averaging.</FONT></TD> <TD>Concerned about the permeability of both Superpave and SMA mixes. One three year old SMA project appears to have stripping problems. Need to look at providing permeable bases with positive drainage under Superpave and SMA projects.</FONT></TD> </TR> <TR> <TD>ME</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load</FONT></TD> <TD>Same as with Marshall or Hveem mixes.</FONT></TD> <TD>Yes</FONT></TD> <TD>Not that we are aware of. we are using 100% 64-28</FONT></TD> <TD>Seems unrelated</FONT></TD> <TD>No</FONT></TD> <TD>More than Marshall or Hveem mixes</FONT></TD> <TD>Contractor and field complaints seem consistent with previous years.</FONT></TD> </TR> <TR> <TD>MD</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load</FONT></TD> <TD>Somewhat more than Marshall or Hveem mixes.</FONT></TD> <TD>Yes, on very few mixes</FONT></TD> <TD>Unmodified PG 70-22</FONT></TD> <TD>12.5mm</FONT></TD> <TD>No</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>We are concerned about segregation that shows up within a year but was not evident during paving. we have been able to achieve specification density on almost all projects. However, our 12.5mm and 19mm mixes require additional compactive efforts. We did not have any significant problems related to the mix design and production.</FONT></TD> </TR> <TR> <TD>MA</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>The MHD has not placed any Superpave mix yet. The first Superpave Pilot project is just getting started.</FONT></TD> </TR> <TR> <TD>MI</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load, center line</FONT></TD> <TD>Same as with Marshall mixes.</FONT></TD> <TD>Yes</FONT></TD> <TD>Primarily PG 58-28. However, the tender zone has appeared with some mixture regardless of the binder grade.</FONT></TD> <TD>No</FONT></TD> <TD>Yes. However as the contractors gain experience problems have reduced. Techniques include: reduce paver speed, increased no. of rollers, change amplitude & freq., comprehensive field density program.</FONT></TD> <TD>More than Marshall or Hveem mixes</FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>MN</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>MS</FONT></TD> <TD>Yes, on some projects let under former spec, the new spec requires MTV w. remixing capability, this change should minimize segregation.</FONT></TD> <TD>End of load</FONT></TD> <TD>More than Marshall or Hveem mixes.</FONT></TD> <TD>Yes</FONT></TD> <TD>Occurring with each of the grades used, PG 67-22, 76-22</FONT></TD> <TD>Occurring in all mix sizes</FONT></TD> <TD>Yes, some contractors are still having problems. usually these are the ones which have made little effort to change their operations & QC to meet the extra compactive efforts needed.</FONT></TD> <TD>More than Marshall or Hveem mixes</FONT></TD> <TD>Isolated cases of rutting, raveling and uncoated aggregates.</FONT></TD> </TR> <TR> <TD>MO</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load and center line</FONT></TD> <TD>Somewhat more than Marshall or Hveem mixes.</FONT></TD> <TD>Yes, on a few</FONT></TD> <TD>Some were with modified binders, some not</FONT></TD> <TD>Most tender mixes were 12.5mm.</FONT></TD> <TD>Yes, most jobs are running consistently on the low side.</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>No other field problems noted.</FONT></TD> </TR> <TR> <TD>MT</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>NE</FONT></TD> <TD>No, none noticed so far</FONT></TD> <TD>N/A</FONT></TD> <TD>Same, no Marshall segregation noticed since getting away from course mixes in 1980's.</FONT></TD> <TD>Yes, on most mixes.</FONT></TD> <TD>No</FONT></TD> <TD>No, Nebraska uses 19mm and 25mm mixes. problem is temperature related in the range of 150 to 250 degrees F.</FONT></TD> <TD>No, just requires more compactive efforts.</FONT></TD> <TD>More efforts required.</FONT></TD> <TD>None, have concerns with T-283 results. They don't trust them yet.</FONT></TD> </TR> <TR> <TD>NV</FONT></TD> <TD>No</FONT></TD> <TD>N/A</FONT></TD> <TD>N/A</FONT></TD> <TD>No</FONT></TD> <TD>N/A</FONT></TD> <TD>N/A</FONT></TD> <TD>Yes, on a limited basis. one project had densities between 88% & 90%. On the other projects there were no problems.</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>In some instances on the various projects there has been reoccurring problems with gradations, Lottman original and retained strengths, air voids and most concerning is stockpile variability. In Nevada, most material sources are alluvial fans with minimal crushable aggregates and in some cases, high PI. we work with these problems but we can not always overcome these issues using Superpave mix design.</FONT></TD> </TR> <TR> <TD>NH</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load</FONT></TD> <TD>Less than Marshall or Hveem mixes.</FONT></TD> <TD>Yes</FONT></TD> <TD>Not binder specific, problems w. PG64-28 & PG58-28</FONT></TD> <TD>More on 12.5mm mixes than 19mm & 25mm mixes. Issues w. 12.5mm mixes are lift tk. & gravel vs. stone.</FONT></TD> <TD> </FONT></TD> <TD>Somewhat more than Marshall or Hveem mixes</FONT></TD> <TD>No, in general both agency and industry are happy with the Superpave mixes.</FONT></TD> </TR> <TR> <TD>NJ</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>NM</FONT></TD> <TD>Very minimal segregation problems, with the larger nominal sizes.</FONT></TD> <TD>End of load, center line</FONT></TD> <TD>Same as with Marshall or Hveem mixes.</FONT></TD> <TD>The problems are related to knowing when to stay off mat, identifying the tender zone.</FONT></TD> <TD>Don't know if its a binder problem or knowing when & how long to stay off the mat. more experience with Superpave designs should help.</FONT></TD> <TD>Feel that bigger nominal sizes (+25mm etc) are giving the most problems.</FONT></TD> <TD>Yes, because of the tender zones, and identifying when to back off.</FONT></TD> <TD>Somewhat more than Marshall mixes</FONT></TD> <TD>Contractors are having trouble with dust proportions, VFAs, VMAs, which I feel can be taken care of in the crushing operation, if the contractor has more control and can crush with more control of the operation.</FONT></TD> </TR> <TR> <TD>NY</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>NC</FONT></TD> <TD>Have not had any segregation problems w. Superpave mixes.</FONT></TD> <TD> </FONT></TD> <TD>Less than Marshall or Hveem mixes.</FONT></TD> <TD>Few mixes had tender zone problems but have not had a problem getting density on those mixes yet.</FONT></TD> <TD>We have only used PG64-22.</FONT></TD> <TD>Our few problems have been on 12.5mm mixes.</FONT></TD> <TD>Our density problems have been few. we require 925 Gmm.</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>No</FONT></TD> </TR> <TR> <TD>ND</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>OH</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>OK</FONT></TD> <TD>We have built 4 Superpave projects this year. all have gone well, with no more segregation problems than with our usual mixes.</FONT></TD> <TD>N/A</FONT></TD> <TD>About the same as with our usual mixes</FONT></TD> <TD>No more so than with our usual mixes.</FONT></TD> <TD>N/A</FONT></TD> <TD>N/A</FONT></TD> <TD>No</FONT></TD> <TD>Same as with our "normal" or usual mixes.</FONT></TD> <TD>No. again, we have only built 4 projects so far this year, but we have had good results in construction of all four.</FONT></TD> </TR> <TR> <TD>OR</FONT></TD> <TD>A few but not wide spread.</FONT></TD> <TD>Center of plane</FONT></TD> <TD>Same as with Marshall or Hveem mixes.</FONT></TD> <TD>Yes</FONT></TD> <TD>We are not in the PG binders yet. Oregon is using PBA system</FONT></TD> <TD>In the 19mm, yes. 12.5mm have been better.</FONT></TD> <TD>Not relative to old mixes</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>No</FONT></TD> </TR> <TR> <TD>PA</FONT></TD> <TD>Yes, only on a few projects.</FONT></TD> <TD>End of load</FONT></TD> <TD>Same as with Marshall or Hveem mixes.</FONT></TD> <TD>Yes, only on a few projects.</FONT></TD> <TD>Not sure, mostly with 64-22 but this is PA's most common grade.</FONT></TD> <TD>Mostly reported on 19mm mixes.</FONT></TD> <TD>No</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>Most tender zone problems have been effectively handled by following the recommendations to stay off the mix if a tender zone is experienced until the temp reaches 190 deg. F.</FONT></TD> </TR> <TR> <TD>PR</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>PR is still working on the Superpave mix design. We have not placed any Superpave pavement yet. </FONT></TD> </TR> <TR> <TD>RI</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>No Superpave mixtures have been placed yet. will soon be placing a test section. </FONT></TD> </TR> <TR> <TD>SC</FONT></TD> <TD>No</FONT></TD> <TD>N/A</FONT></TD> <TD>Less than Marshall or Hveem mixes.</FONT></TD> <TD>Yes, but minor in nature.</FONT></TD> <TD>PG64-22 (neat)</FONT></TD> <TD>Not really</FONT></TD> <TD>Only a little, much less than in the early years</FONT></TD> <TD>Somewhat more than Marshall or Hveem mixes, if breakdown roller is kept right behind the paver, density is not a problem.</FONT></TD> <TD>No, satisfied with our Superpave mixes, concerned about the permeability issue. </FONT></TD> </TR> <TR> <TD>SD</FONT></TD> <TD>No (based on 2 projects with Superpave mixes in 1999)</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>Yes, but was not any more of a problem than some Marshall mixes.</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>Required density was obtained on 2 projects constructed in 99.</FONT></TD> <TD>May have required more compaction efforts than conventional Marshall mixes.</FONT></TD> <TD>The SDDOT has not used a lot of Superpave mixes. constructed 2 projects w. 12.5mm mixes in 1999. projects went well & segregation was not a problem. </FONT></TD> </TR> <TR> <TD>TN</FONT></TD> <TD>No</FONT></TD> <TD>N/A</FONT></TD> <TD>Same as with Marshall mixes.</FONT></TD> <TD>Yes, only on 2 out of 18 projects, one of these went through the restricted zone</FONT></TD> <TD>No</FONT></TD> <TD>No</FONT></TD> <TD>Yes, only on 1 mix</FONT></TD> <TD>More than Marshall or Hveem mixes</FONT></TD> <TD>None</FONT></TD> </TR> <TR> <TD>TX</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load</FONT></TD> <TD>Less than Marshall or Hveem mixes.</FONT></TD> <TD>Yes, on some mixes</FONT></TD> <TD> </FONT></TD> <TD>Mostly in 19mm, not as much in 12.5mm mix.</FONT></TD> <TD>On some jobs</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>Problems with non-uniformity of PG 70-22 binder. Some of the binder delivered to the job is too stiff. We are looking at upper limits on DSR or lowering the max allowable viscosity at 275 F. </FONT></TD> </TR> <TR> <TD>UT</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load</FONT></TD> <TD>Same as with Marshall or Hveem mixes.</FONT></TD> <TD>No</FONT></TD> <TD>N/A, we have not experienced tender zone related problems this year.</FONT></TD> <TD>N/A, we have not experienced tender zone related problems this year.</FONT></TD> <TD>No</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>In some areas of the State, UDOT is having problems verifying that the contractor's mix design meets the voids and VMA requirements.</FONT></TD> </TR> <TR> <TD>VT</FONT></TD> <TD>No</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD>Wide track rubber tire rollers can roll through the tender zone</FONT></TD> <TD>No</FONT></TD> <TD> </FONT></TD> <TD>Yes, 19mm</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>The lay down thickness is more than the Marshall mixes. The Superpave mixes appear to be more permeable.</FONT></TD> </TR> <TR> <TD>VA</FONT></TD> <TD>Yes</FONT></TD> <TD>End of load (base mixes), center line (occasional)</FONT></TD> <TD>Same as with Marshall or Hveem mixes.</FONT></TD> <TD>Yes, occasional tenderness.</FONT></TD> <TD>PG64-22</FONT></TD> <TD>9.5mm and 12.5mm</FONT></TD> <TD>Yes, due to higher laboratory compaction for Superpave compared to Marshall compaction.</FONT></TD> <TD>More than Marshall or Hveem mixes</FONT></TD> <TD>Problems obtaining the required VMA, VFA</FONT></TD> </TR> <TR> <TD>WA</FONT></TD> <TD>There have been a few segregation problems on Superpave projects this year. They have all been corrected in the field, and were not considered a "big deal". A transfer device and keeping the hoppers full has really helped our segregation problems here.</FONT></TD> <TD>A specific type of segregation is not really common.</FONT></TD> <TD>Hard to compare, have used the transfer devices on many of the Superpave and conventional mixes and have had very little segregation. before we used the transfer device, the Hveem mixes showed end dump segregation.</FONT></TD> <TD>A few encounters with the tender zone, but they are usually resolved in the test section, the first day of paving. WADOT tries to ensure good volumetrics and compaction and this usually keeps us away from the tender zone.</FONT></TD> <TD>More challenging to get compaction with the stiffer grades, but the tender zone is not more common with any type of oil.</FONT></TD> <TD>No</FONT></TD> <TD>Not really any problems with compaction that could not be solved by the time the test section, 800 tons, was complete.</FONT></TD> <TD>Compactive effort is often times harder to achieve with the Superpave mixes, but there have not really been any compaction problems.</FONT></TD> <TD>Not particularly.</FONT></TD> </TR> <TR> <TD>WV</FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> <TD> </FONT></TD> </TR> <TR> <TD>WI</FONT></TD> <TD>Nothing significant</FONT></TD> <TD> </FONT></TD> <TD>Same as with Marshall or Hveem mixes.</FONT></TD> <TD>Some minor problems, not consistant</FONT></TD> <TD>We typicaly use a PG58-28 statewide and the tenderness problems we have seen seem to be related to this grade</FONT></TD> <TD>No</FONT></TD> <TD>Only minor problems</FONT></TD> <TD>Somewhat more than Marshall or Hveem mixes</FONT></TD> <TD>The only other concern noticed is that the Superpave mixes seem to be more sensitive to changes in aggregate gravities.</FONT></TD> </TR> <TR> <TD>WY</FONT></TD> <TD>No more of a problem than w. our Marshall mixes.</FONT></TD> <TD> </FONT></TD> <TD>Same as with Marshall or Hveem mixes.</FONT></TD> <TD>Yes, on all mixes <B>(one project only)</B></FONT></TD> <TD>No specific binder stands out as having more of a tender zone problem than another.</FONT></TD> <TD>No</FONT></TD> <TD>Not unlike problems usually encountered with our Marshall mixes.</FONT></TD> <TD>Same as with Marshall or Hveem mixes</FONT></TD> <TD>No, we have only one Superpave project and it is currently under construction. Therefore, the answers are based on limited experience with this one project only.</FONT></TD> </TR> </TABLE> </TD></TR> <TR><TD COLSPAN="2" ALIGN="center"><BR> See also the web site for the <A HREF="http://www.aashtotig.org/"><FONT SIZE="2" COLOR="000000">AASHTO Technology Implementation Group</FONT></A></TD></TR> </TABLE> </BODY>