Ritchie Bros. Las Vegas auction coinciding with ConExpo-Con/Agg brings in $60 million-plus
Coinciding with ConExpo-Con/Agg 2014 last week, the every-three-year concrete/aggregate equipment show, Ritchie Bros. Auctioneers broke several of its side records with its auctions on March 6 and 7 that brought in more than $60 million in gross auction proceeds, had more than 4,750 registered bidders, more than 450 sellers and 900 total buyers, at its permanent auction site in Nevada.
Ritchie Bros. says the two-day unreserved public auction broke several site records for online sales, including more than $19 million in online gross auction proceeds, 2,900 online registered bidders and more than 400 online buyers.
More than 2,350 equipment items, including motor graders, hydraulic excavators, backhoes and skid steer loaders, were sold in the auction, with every item sold without minimum bids or reserve prices, according to Ritchie Bros. Auctioneers.
At the time of this posting, the company’s next unreserved public auction in Las Vegas was slated for June 6.
Auction Quick Facts for March 6-7, Las Vegas:
Total Gross Auction Proceeds (in-person and online): US $60+ million (*new Las Vegas, NV permanent auction site record)
Amount sold online: $19+ million (*new Las Vegas permanent auction site record)
Unique registered bidders (total): 4,750+ (*new Las Vegas permanent auction site record)
Unique registered online bidders: 2,900+ (*new Las Vegas permanent auction site record)
Online buyers: 400+
Total number of lots sold: 2,350+
Total number of sellers: 450+ (*new Las Vegas permanent auction site record)
Source: Ritchie Bros. Auctioneers
Manitou previews MHT 1490 telescopic handler at ConExpo-Con/Agg
Manitou showcased a prototype of its MHT 1490 high-capacity telescopic handler at ConExpo-Con/Agg 2014 in Las Vegas.
A 176-horsepower Tier 4 Final Mercedes engine with four cylinders powers the telehandler and is equipped with an exhaust gas recycling (EGR) valve and selective catalytic reduction (SCR) that requires diesel exhaust fluid (DEF). A hydrostatic transmission coupled to a gearbox delivers speeds up to nearly 25 mph.
The 42,990-pound machine has a lift capacity of up to 19,850 pounds; a lift height of up to 46 feet; a turning radius of 13 feet, 2 inches; and a width of 8 feet, 3 inches.
The cab includes a longitudinal stability indicator, frame leveling, a load status regulator to improve safety during handling and a Joystick Switch & Move (JSM) single lever control for stability.
The telehandler features a chassis reinforcement designed to handle heavy loads, a triplex chain boom that keeps all machine components inside the telescopic tube to avoid damage, automatic rear axle locking to increase stability and an attachment fitting system that allows the operator to quickly add an attachment to the machine.
Proportional valves make the machine easy to level, according to the company. The valves can correct leaning of 6.5 degrees on the stabilizer or 8 degrees on the tires.
The Bearded Editors of Construction
For those of you who were at ConExpo-Con/Agg last week, you know how busy this show has been. I’m sure many of you have seeing the editors running – literally – from one press event to another trying to cram in booth visits in between writing up show coverage.
But after a day of walking about 10 miles (Yes, we tracked it!) during the show and “getting up at the ‘butt crack’ of dawn” (as one manufacturer rep who held a 7 a.m. press conference referred to it), several construction industry editors let loose to go see the bearded wonders of ZZ Top.
Here are some embarrassing images to show that editors have fun, too! (Although, we did find ourselves pointing out all the grammatical mistakes on signs on our way the show.) Do you like how we tried to copy ZZ Top’s signature style with a long beard and sunglasses?
If you have any fun images from the show (keep them clean, please) that you want to share, send them to me at firstname.lastname@example.org and let me know where they were taken.
Transportation Talk: Can We Stop a ‘Painful’ Transportation Situation?
We’re in trouble – big trouble – and it’s going to be hard to find a way out. It’s not news to anyone in the transportation construction industry that the nation’s Highway Trust Fund (HTF) is in peril. So far, we’ve put on Band-Aids to scrape by and keep things functioning. But this isn’t just a scratch. We’re hemorrhaging, and if we don’t use a “tourniquet,” the nation’s infrastructure system is going to bleed to death. That tourniquet is a new source of revenue.
Related: VIDEO: ARTBA President Pete Ruane urges ConExpo-Con/Agg attendees to tell Congress to fix Highway Trust Fund
Fixing the HTF without any new revenue would require the equivalent of Congress passing and the president signing a 2013-level Murray-Ryan budget deal every year just to maintain current highway and transit program investments, says Pete Ruane, president of the American Road & Transportation Builders Association (ARTBA), to a Senate panel last month. (The Act is the bipartisan compromise reached by Sen. Patty Murray, D-Wash., and Congressman Paul Ryan, R-Wis.) The HTF will not be able to support any investments in new projects after September. A recent Congressional Budget Office (CBO) report found an average of $16.3 billion is needed each year to preserve the current transportation program. By comparison, according to ARTBA, during a two-year period, the Bipartisan Budget Act of 2013 reallocates resources to increase the no-defense discretionary spending cap by about $16 billion per year.
Ruane cautioned the Senate Environment & Public Works Committee that a “painful scenario” is ahead of us. If the HTF shortfall isn’t addressed, he said the more than 12,000 highway bridge and safety capital projects throughout the nation could be lost. (Go to youtube.com/watch?v=ZFYaSxatANI#t=79 to see a video from Ruane.)
In 2015, the HTF highway account will have insufficient revenues to meet its obligations, resulting in steadily accumulating shortfalls, according to the CBO report. Under current law, the HTF cannot incur negative balances and has no authority to borrow additional funds. However, following the rules in the Deficit Control Act of 1985, CBO’s baseline for highway spending incorporates the assumption that obligations incurred by the Highway Trust Fund will be paid in full.
The U.S. Department of Transportation has indicated it needs at least $4 billion in cash balances available in the highway account and at least $1 billion in the transit account to meet obligations as they are due, the CBO report notes. This means, according to the CBO’s baseline projections, the highway account may have to delay some of its payments until the latter part of 2014.
The inadequate revenue is like watching our nation’s infrastructure bleed out. As the nation continues in a slow economic recovery, we need to ensure the HTF remains solvent.
To avoid this “painful” scenario, please talk to your Congressman or Congresswomen and let him or her know not only does your job depends on this, but also the nation’s health.
The Last Word
By Tina Grady Barbaccia
The Roadologist Blog
For more blogs from Better Roads, visit betterroads.com.
I wasn’t sure at first what kind of reaction I would get to the “‘Booth babes’ and the S.T.E.A.M. professions” blog post I recently wrote (betterroads.com/booth-babes-and-the-s-t-e-a-m-professions), but it has really generated reader dialogue. In fact, I’ve been able to post several reader responses, some of which I have shared here. I spent a week at World of Concrete 2014 in Las Vegas in January to learn about the latest technology, see new and updated equipment and talk with manufacturers, contractors and agency transportation professionals, enhance my industry knowledge and build relationships. However, when I was on the tradeshow floor I was a bit disappointed to see that some exhibitors are still hiring “booth babes,” doing a disservice to the Science, Math, Engineering, Art and Design, and Technology (S.T.E.A.M.) professions. (You can read the original post, but I think the reader responses are more entertaining.)
Male reader and well-respected industry figure, “J.A.M.,” said, “I am a middle-aged male, relatively well-known industry professional who appreciates an attractive woman’s figure as much as most men do. But it is almost embarrassing to walk up to a vendor whose products in which you may actually have interest and feel like a voyeur because of the ‘eye candy’ standing around. I for one don’t want to risk the appearance in my colleagues’ eyes of being interested in that aspect of the booth vs. the actual product displayed.” For the rest of his comments, go to betterroads.com/one-reader-responds-to-booth-babes-blog-post.
A female equipment manager shared a story, which I found very amusing. She brought her husband with her – an imposing figure at 6 feet, 7 inches tall – who does not work in the construction industry. When the couple would walk up to booths together, he developed this response for when sales people would automatically walk up to him and ignore her: “That sounds great, but I didn’t understand anything you just said. You need to talk to her! I’m just here to hold the bag.” She said this gave her a nice chuckle and then added, “I guess my husband is kind of my own personal booth babe.” For more reader feedback and stories, go to “The Saga Continues: More readers share stories, opinions on ‘booth babes’” at betterroads.com/the-saga-continues-more-readers-share-stories-opinions-on-booth-babes.
After reading an article about this in Fast Company (fastcompany.com/3025457/leadership-now/8-of-the-strangest-interview-questions-job-candidates-have-asked), I felt like I had just looked at an article out of The Onion, a satirical (but in my opinion, very well-written) take on real news.
These questions asked by potential job candidates showcase bad manners and are just downright odd. One candidate’s mom came along for an interview because she was afraid her shy daughter might forget something important. Another job candidate asked the potential employer to pay him less than a living wage so he could stiff his wife in their divorce. Then there was the interviewee who asked if it was OK if he barked at the dogs in the pet-friendly office to show his dominance. You can’t forget the candidate who asked to eat lunch during the interview, the one who asked if it was OK to grab snacks from the kitchen, the candidate who wanted to know whether the potential boss was single and the job applicant who asked when she would be able to pass a drug test if she had just smoked marijuana. For The Roadologist post on this, go to betterroads.com/8-strange-interview-questions-or-how-not-to-get-hired.
What is the oddest interview question you have been asked by a potential job candidate or a potential employer? What is the most unique question you may have asked a job applicant?
New Road Products
Special ConExpo-Con/Agg coverage. Please see betterroads.com for additional products and press event coverage.
ConExpo-Con/Agg Booth 51021 in Central Hall
Wirtgen is debuting its W 250i cold-milling machine at ConExpo-Con/Agg. The company’s largest cold-milling machine, the W 250i has an extra-large milling drum; a working width of 12 feet, 6 inches; a camera system; a Vacuum Cutter System (VCS); a dual-engine concept; and three milling drum speed options. wirtgenamerica.com
ConExpo-Con/Agg Booth 10016 in North Hall
Komatsu America is showcasing its four intelligent Machine Control (iMC) dozers at ConExpo-Con/Agg. The dozers are designed to seamlessly transition from rough dozing to finish grading, and they feature an integrated sensor package. komatsuamerica.com
ConExpo-Con/Agg Booth 31040 in Central Hall
Leading Edge Attachments (LEA) is featuring six attachments – five buckets and one stump removal tool – at ConExpo-Con/Agg. The company is displaying its High-Cap, Multi-Ripper Bucket that acts as a trencher; Multi-DigNRip Bucket for high-production rip and load applications; new Stag Bucket with “Staggered Tooth” technology; V-Raptor Bucket ripper/bucket combination for excavators and backhoes; Stumpiranha stump removal tool; and Multi-Ripper Talon Bucket narrow bucket with a center rib that can be eliminated. leadingedgeattachments.com
New to Hyundai’s 9A series, the R55-9A and R55W-9A mini excavators feature improvements from previous models, including a certified Tier 4 Final engine upgrade, improved hydraulics, increased operator comfort and added durability. The R55-9A track model and R55W-9A wheeled model have operating weights of 12,460 pounds and 12,240 pounds, respectively. hceamericas.com
Saw Seal’s new Saw Seal Machine cleans and seals multiple joints simultaneously in new concrete pavement. Features include a blade-only contact method that controls cracking as the concrete cures, a HEPA filtration vacuum system that collects dust and silica, a 55-gallon drum that stores dust and silica, a compressed air nozzle that cleans and dries the joint and a Crafco EZ Series II 1500 melter that applies sealant in the finals stage. sawseal.com
The first of its kind, Genie’s telematics-ready connector features a “plug and play” option for Genie boom lifts. Available on Genie S-80 and Z-80 boom lifts, the factory-installed connector offers hour meter reporting, location, machine use and several security features. The connector will be available on S-100, S-120 and ZX-135 models by the end of the first quarter. genielift.com
ConExpo-Con/Agg Booth 65830 in South Hall
Illumagear’s Halo Light Personal Active Safety System, which the company is displaying at ConExpo-Con/Agg, attaches to a hard hat to illuminate 360 degrees of a worker’s task area. Designed to eliminate shadows, the light provides visibility up to 1/4 mile away and offers four light modes: Halo, Hi-Alert, Task and Dim. A tension spring-mounting system connects the system to most hard hats. illumagear.com
Henderson Products has introduced the BrineXtreme, a mobile salt brine solution that produces professional grad salt brine on the go. Designed to provide a concentration that is accurate to 01001 SG, the unit is able to work in temperatures as low as -6 degrees F and can perform pre-storm applications. The unit has a production rate of up to 160 gallons per minute and a 5-cubic-yard capacity. hendersonproducts.com
Neal Manufacturing’s heavy-duty ESSP 550T and 750T trailer-mounted sealcoating machines have electric super sand pump (ESSP) systems that produce up to 100 gallons per minute and a water tank hand-wand holder that prevents the sealer from leaking. The 550T and 750T have capacities of up to 550 gallons and 750 gallons, respectively. Features include 75 feet of reinforced hose, a 6-foot hand wand, a six-nozzle spray bar, 2.5-gallon material fillers, Neal’s Generation III pump heads and more. nealequip.com
Public vs. Private Distinction
Why knowing the allowable timeline to bring a lawsuit is important
The distinction between a public and private work of improvement is an important one for contractors. Public works of improvements are subject to laws that do not affect private projects.
For example, public projects are subject to bonding requirements, prevailing wage requirements and other laws and requirements that do not apply to private jobs. Although it is typically obvious whether a project is public or private, the distinction is not always clear.
In a recent California case – R&R Pipeline, Inc. v. Bond Safeguard Insurance Co. (Jan. 27, 2014) – the court held that a contractor who provided storm drain and sewer work for a golf course subdivision could bring a lawsuit to enforce a subdivision improvement bond because the project was private and not public.
In May 2008, R&R entered into a written contract with Los Valles Company, LP for infrastructure work on land being developed by Los Valles as a golf course and residential community. The project involved an 18-hole golf course designed by Arnold Palmer and 209 residential lots in Los Angeles County near Castaic, California. The project included the construction of improvements such as streets, sidewalks, gutters, storm drains and sewers, which were to be dedicated to the county upon completion.
As part of the project, in December 2006, Los Valles entered into a Public Works Multiple Agreement (Multiple Agreement) with Los Angeles County. The Multiple Agreement required Los Valles to complete the subdivision improvements, including the work contracted for with R&R, to receive a final map. Bond Safeguard issued labor and material payment bonds covering the work. The County was the beneficiary under the bonds, and Los Valles was the principal. The bonds provided that Bond Safeguard would pay for any work or labor performed by R&R under its contract with Los Valles. The work was to be completed by Los Valles to the satisfaction of the County. R&R performed work up to Oct. 1, 2008.
R&R performed its work, and Los Valles breached the contract by failing to pay the sums due. R&R claimed it was owed more than $1.2 million, including $1,085,858.64 under the contract, and an additional $150,000 in restocking charges on materials ordered. In December 2008, R&R filed a lawsuit against Los Valles. On May 17, 2011, R&R first notified Bond Safeguard in writing of its claims. R&R did not give written notice to the county. On July 25, 2011, R&R named Bond Safeguard as a defendant in its lawsuit. None of the subdivision improvements were completed and dedicated or accepted by the county.
The trial court ruled against R&R and in favor of Bond Safeguard. The trial court found the project was a public work of improvement, based on the Multiple Agreement that required Los Valles to construct improvements (sewers, storm drains, and tunnels) according to the County’s approved plans. Since it found the project was a public work, the trial court found R&R failed to give timely notice of its claim to the County or Bond Safeguard and entered judgment for Bond Safeguard. R&R appealed.
The appeals court reviewed the record and found the Multiple Agreement was not a public works contract because the county was not an owner, did not have a contract with R&R was not seeking payment from the county. In addition, R&R’s work was performed on private land, which was never accepted by the county. Further, the project was not described as a public improvement in the Multiple Agreement or payment bond. Finally, the amount of the payment bonds were only about 50 percent of the estimated cost of improvements, while public works projects require bonds that are at least 100 percent of the contract amount.
Since the project was private, R&R was not subject to the notice requirements for public projects and had four years to file suit against Bond Safeguard. As a result, the appeals court reversed the judgment against R&R.
The R&R Pipeline case illustrates one important distinction between public and private projects – the allowable timeline to bring a lawsuit on a labor and material payment bond. Here, the public versus private distinction was critical to R&R being permitted to continue with its lawsuit seeking more than $1.2 million in damages.
In addition to bonding issues, the public versus private distinction has important implications in other areas, including public bidding laws, prevailing wage requirements and public contracting requirements. It is important for contractors to understand the realm in which they are contracting – public or private – and applicable legal requirements so they can best protect their rights.
Attorney Brian Morrow is a partner in Newmeyer & Dillon LLP and a licensed civil engineer specializing in construction law including road and heavy construction.
Special Report from TRB 2014: Warm Mix Asphalt
The incursion of warm-mix asphalt (WMA) into the nation’s bituminous pavements continues unabated.
The latest National Asphalt Pavement Association (NAPA)/Federal Highway Administration (FHWA) survey of asphalt producers’ use of recycled materials and warm-mix asphalt find that nearly a quarter of all asphalt produced during the 2012 construction season was produced using warm-mix asphalt technologies.
The survey, conducted by NAPA under contract to FHWA, found a total of 86.7 million tons of WMA were produced in 2012, a 26-percent increase since 2011 and a 416-percent increase in the use of warm mix since the survey was first conducted in 2009. The full survey may be downloaded at asphaltpavement.org/recycling.
The interest in WMA is reflected by the large number of peer-reviewed technical papers on WMA presented at the 93rd annual meeting of the Transportation Research Board (TRB) meeting in Washington, D.C., in January.
The annual event was held Jan. 12-16 and kicks off the year for the surface transportation community. Nearly 12,000 transportation professionals came to Washington from around the world for the 2014 event.
The TRB Annual Meeting program covered all transportation modes, with more than 4,500 presentations in nearly 800 sessions and workshops addressing topics of interest to stakeholders in government, industry and academia.
For nearly 60 years, TRB has been held among a cluster of hotels along Connecticut Avenue near Woodley Park and the National Zoo, but in 2015 it will move to bigger digs at the Walter E. Washington, D.C., Convention Center.
Following are summaries of some of the technical papers at TRB of interest to the readers of Better Roads. For more information, visit trb.org.
Evaluation of WMA performance in Florida
Use of warm-mix asphalt is indicated for paving in cold ambient conditions or long hauls from the plant, during which the temperature of hot-mix asphalt can swiftly decline to the point that it loses workability.
Before WMA, plants would produce mixes at higher-than-optimum temps in the hopes that the mix would retain workability on arrival at the jobsite. But this excessive heat had the effect of “prematurely aging” the liquid binder in the mix by burning off the lighter hydrocarbons that give the pavement resistance to thermal cracking and other ills. Typically, those lighter fractions would be driven off by slow weathering and aging during the years.
But WMA is useful for hot climates as well, as their volatile organic compound (VOC) emissions are substantially below that of HMA mixes, enhancing working conditions and the urban environment. One by one, states are evaluating the benefits of WMA – which comes at a higher price than conventional HMA – and Florida is that latest warm-climate state to review its use.
In Florida, WMA performance in terms of cracking, rutting, and pavement smoothness is comparable to that of HMA, say Bouzid Choubane, Sanghyun Chun, Hyung Suk Lee, Patrick Upshaw, James Greene and Abdenour Nazef, of the Florida DOT Materials Research Park in Gainesville, in their paper, Evaluation of Warm-Mix Asphalt (WMA) Performance in Florida.
They say with WMA, asphalt fumes and 26 aerosols have been reported to be reduced by 30 to 50 percent, while reductions reported for carbon dioxide (CO2) and sulfur dioxide (SO2) have been in the range of 30 to 40 percent. Reductions of 10 to 30 percent of carbon monoxide (CO) and 20 to 25 percent of dust also have been reported. Florida DOT started using the WMA technology in 2006 based on reported benefits due to lower asphalt mixing and compaction temperatures.
“Limited field and laboratory studies have indicated that WMA may have similar performance as traditional hot-mix asphalt,” they write. “However, some studies have also suggested that the use of WMA may increase long-term rutting and stripping potential, and hence the long-term performance evaluation of the WMA mixtures is still warranted.”
With the primary objective of obtaining long-term field performance data of Florida’s WMA, the respective field performance of six representative WMA projects using five different technologies (one chemical additive and four water foaming technologies) was monitored and documented. The performance of the WMA projects was then compared to the historical performance data of Florida’s asphalt pavements.
“The results to date indicate that WMA performance in terms of cracking, rutting and pavement smoothness is comparable to that of HMA,” the authors conclude. “These projects will continue to be monitored to further assess their long-term field performance.”
WMA modifier eliminates drain-down fibers from OGFCs
In addition to its other benefits, at least one warm-mix asphalt modifier can eliminate the expense of adding fibers to liquid binder used for open-graded frictions courses, say Bradley J. Putman and Kimberly R. Lyons, Glenn Department of Civil Engineering, Clemson University, South Carolina, in their paper, Evaluation of Warm Mix and Rubber Modified OGFC Test Sections Made Without Fibers in South Carolina.
Open-graded friction courses (OGFCs) enhance the tire-pavement interface while keeping surface water off the pavement, making them safer than conventional pavements. But because they lack fines, drain-down of liquid binder in early OGFCs quickly led to raveling of their surfaces, so much that they were banned by some departments of transportation (DOTs).
Since then, the advent of polymer modified asphalt binder has led to more durable OGFCs. While modifiers will help keep liquid asphalt binder from moving within an open-graded mix, it still may puddle at the bottom of a haul truck or settle lower in the lift of mix just placed.
This drain-down of asphalt seriously compromises the durability of OGFCs. The problem with the drain-down of liquid asphalt is solved by use of fibers – typically cellulose, but also mineral filler – which are used to hold the binder in place.
But research presented at TRB indicates a WMA modifier can halt drain-down in OGFCs as well. Pulman and Lyons’ paper summarizes the performance of OGFC mixtures used to construct two separate experimental pavement test sections in South Carolina, with the main objective to evaluate OGFC mixtures made without fibers.
One test section consisted of three OGFC mixtures (control with cellulose fibers ground tire rubber modified without fibers, and WMA without fibers), and the second consisted of two OGFC mixtures (control with cellulose fibers and WMA without fibers).
“Material was sampled from the asphalt plant during production, and tests were conducted on the fresh mix, as well as specimens compacted at the plant and after reheating in the research lab,” the authors write. “The results showed that the removal of fibers from the OGFC mixtures in both projects did not have any detrimental effects on the mix performance (drain-down, permeability, abrasion resistance, indirect tensile strength and fatigue resistance).”
The WMA mixture was made with Evotherm modifier and exhibited increased fatigue resistance compared to the control mixture, even though the mix did not contain cellulose fibers, they say.
“Additionally, the WMA mixture showed the potential to reduce heat loss due to start-up of the paving operation (i.e., running asphalt mix through a cold material transfer vehicle and then a cold paver),” they say. “Limiting heat loss could improve the consistency of the OGFC mat density from the beginning transverse cold joint, thus potentially enhancing the pavement performance.”
With care, high-RAP mixes can serve Virginia roads
Asphalt mixes containing up to 45-percent reclaimed asphalt pavement (RAP) are viable for the Commonwealth of Virginia, so long as care is taken in production and construction, say Stacey Diefenderfer, Ph.D., P.E., and Harikrishnan Nair, Ph.D., P.E., Virginia Center for Transportation Innovation and Research, Charlottesville, in their paper, Evaluation of High RAP Mixture Production, Construction and Properties.
In 2007, the Virginia Department of Transportation (VDOT) introduced specifications to allow RAP percentages of up to 30 percent in asphalt surface mixtures without a change in the virgin binder grade, the authors write, adding since 2007, increasing material costs and a growing awareness of the quantity of RAP available for use have sparked interest in asphalt mixtures having a higher percentage of RAP.
Recently, they say, VDOT began to consider allowing the use of surface mixtures with RAP contents of up to 45 percent, and in June 2013, a trial was constructed containing mixtures with 20, 30, 40 and 45 percent RAP for evaluation. The trial indicated higher RAP contents can be tolerated with no loss in performance.
“In general, mixtures containing up to 45-percent RAP can be successfully designed, produced and constructed if proper procedures are followed and attention to detail is paid during design, production and construction,” Diefenderfer and Nair say. “In addition, dynamic modulus and flow number test results indicated no significant difference in performance should be expected among the mixtures evaluated, despite slight differences in volumetric properties.”
They conclude the following:
• Based on the dynamic modulus and flow number tests, the 40- and 45-percent RAP mixtures should perform similarly to the 20- and 30-percent RAP mixtures evaluated.
• Based on the dynamic modulus and flow number tests, the 30-percent RAP mixture containing a blend of natural and manufactured sand did not behave significantly differently than the 30-percent RAP mixture containing only manufactured sands. Binder absorption and effective asphalt content were affected by the presence of the natural sand.
• The dynamic modulus and flow numbers for the mixture containing 20-percent RAP and PG 70-22 binder were not significantly different than those for the mixtures containing 30-percent RAP and PG 64-22 binder. Binder testing will be performed to verify further the expected performance of these mixtures.
In Kansas, right RAP rectifies road rutting
Recycled Superpave mixtures with crushed gravel aggregates and sand significantly improve overall rutting performance compared to the crushed stone or crushed stone/gravel combination in the mix, say Farhana Rahman, Ph.D., Seattle University; Mustaque Hossain, Ph.D., P.E., Kansas State University; and Cliff Hobson, P.E., and Greg Schieber, P.E., Kansas Department of Transportation, in their paper, Performance of Superpave Mixtures with High RAP Content in Kansas.
The Kansas DOT has been evaluating performance of Superpave mix designs with higher percentages of RAP. Hamburg Wheel Tracking Device (HWTD) tests were done on Superpave mixes with high RAP content sampled from a number projects across the state. Each mixture was subjected to 20,000 repetitions or 20-mm rut depth, whichever came first.
Tests for predicting moisture damage and rutting potential of the Superpave mixes with RAP and temperature stress restrained specimen tests (TSRSTs) for predicting low temperature cracking susceptibility also were done on selected mixes.
Based on this study, the authors articulated these conclusions:
• The number of wheel passes and rut depth from Hamburg wheel tracking device tests are significantly different for the Superpave mixes with different RAP contents, though the trend of this variation is inconclusive.
• Recycled Superpave mixtures with crushed gravel aggregates and sand significantly improve the overall rutting performance, compared to the crushed stone or crushed stone/gravel combination in the mix.
• Recycled mixes with higher PG binder grade had higher number of wheel passes with lesser accumulation of rutting. However, the interaction study between aggregate type and PG binder grade is inconclusive.
• Rutting performance of Superpave mixes with RAP is significantly affected by the binder source, regardless of the performance grade of the binder. However, higher PG binder grade improves the rut resistance.
• Statistical analysis proved the total number of wheel pass, creep slope and stripping slope of the Superpave mixes with RAP in the HWTD tests are significantly affected by the RAP content, binder grade and asphalt sources at 90-percent confidence interval.
• RAP percentage in the mix, aggregate type and interaction between RAP content and aggregate type also affect the pure stripping failure phase (stripping slope) and the total wheel passes at the stripping inflection point.
• The analysis of variance (ANOVA) on Superpave mixtures with RAP shows the number of wheel passes at stripping inflection point and stripping slope are significantly affected by mix type and binder source.
• ANOVA analysis also shows the rutting performance is highly influenced by the voids in mineral aggregate and RAP asphalt content. However, performance parameters are insensitive to the virgin asphalt content, voids filled with asphalt and dust-to-binder ratio of the mix.
• TSR values are significantly correlated (negatively) with the percent RAP in the mixture at 90-percent level of confidence or in other words, the mixtures become more susceptible to moisture damages the RAP content increases.
• Superpave recycled mixtures with higher RAP contents tend to show lower fracture temperatures, indicating these mixtures are more vulnerable to low temperature cracking.
Sustainable concrete fines from dredged materials
Remediated dredged materials may play a role as extremely fine material added to concrete, say two researchers from Florida.
Dredging spoil usually is dumped at sea, but its fine nature makes it eligible for addition to portland cement concrete as a reclaimed material, say Nemmi Cole and Doreen Kobelo Ph.D., Florida A & M University, Tallahassee in their paper, Sustainable Use of Dredged Materials in Roadway Construction.
Dredging of waterways produces large volumes of dredged material, containing various contaminants – from heavy metals to pesticides – making its disposal increasingly problematic, they write. “Major ports are in need of an environmentally sound and economically feasible solution for this potentially hazardous material,” Cole and Kobelo say. “Dredged material is a valuable resource that can be used as filler, which is useful for the applications aside cement composites.
“Fillers are widely used in road construction and various other industries, due to its small average particle size and chemically active silt/clay fraction,” they note. “After proper treatment, dredged material has the potential to become a major contribution toward sustainable development and can reduce the quantities of primary resources needed for activities such as construction.”
Dredge material is seen as a valuable resource, and innovative methodologies for its beneficial use are in the infancy stage of development worldwide, Cole and Kobelo write.
Web Exclusive: Read “Dredged Material Mostly Clay, Sand,” which explains how the material can be used as filler, at betterroads.com/dredged-material.
CORRECTION: In the February 2014 Road Science article, “Materials that Make a Difference,” reference is made to “high-density polypropylene (HDPE)” pipe. That should have read as “high-density polyethylene (HDPE)” pipe. References later in the article to polypropylene fibers for concrete are correct.
The Magic of Rubberized Asphalt
As prices for asphalt cement (AC) and polymer have shot up dramatically, agencies and contractors are looking for ways to hold the line on the cost of asphalt pavements.
By Daniel C. Brown
The number of transportation agencies that use recycled tire rubber in asphalt has increased steadily in recent years. Several states have specifications for adding recycled tire rubber to asphalt binder, including Florida, Georgia, Louisiana, Texas, Arizona and California.
As prices for asphalt cement (AC) and polymer have shot up dramatically, agencies and contractors are looking for ways to hold the line on the cost of asphalt pavements. Currently, almost 20 percent of the asphalt binder sold in the United States for paving is polymer modified. This makes rubber an economically attractive extender of asphalt, since it contains both polymer and oil. Also, the price of recycled tire rubber is stable, unlike the price of AC and polymer.
Recycled tire rubber can be added to asphalt in three ways, says Doug Carlson, vice president of asphalt products for Liberty Tire Recycling, a Pittsburgh-based rubber provider. The classic method, specified by ASTM D6114, is called asphalt rubber, or the Arizona method. It is a wet process. Recycled tire rubber is added at close to 20 percent by weight of the liquid AC. The rubber particles are fairly large – up to 2 millimeters in size. The process requires special blenders that can be used in the field to react the rubber with AC.
Asphalt rubber has found its place in heavy-duty chip seals and in surface mixes that are gap graded to have space for the rubber particles. Open-graded friction courses (OGFC) and stone-matrix asphalt (SMA) can make good use of asphalt rubber. The material is comparable to an asphalt modified with 7 percent polymer, says Carlson.
He calls the second method the “Polymer Switch Binder.” The rubber can be blended at an asphalt terminal, or added in the field with the same equipment that asphalt rubber is made with. A finer-grind rubber is used – particles of half a millimeter – and it is typically added at 8 to 12 percent of the weight of the AC. The AASHTO M320 spec will soon be changed to allow particulate tire rubber to be used in performance-graded binders and Superpave mixes, Carlson says.
More than ever, terminal or refinery facilities are either considering supplying rubber-modified binders or do supply them, says Jeff Smith, technical director for Cactus Asphalt, an asphalt rubber binder supplier. “That’s a change in our industry, because in the past they have been totally resistant to that,” Smith says. The reason is the lower cost of recycled tire rubber. “Even if it takes three times the tire rubber percentage to do what one percent of virgin polymer will do, still, the overall cost to the manufacturer is much less to use tire rubber.”
The third method is a newer dry process, approved by specification in Georgia. “It’s a very fine-grind rubber, less than 600 microns in size. And the dosage is only around 10 percent by weight of the binder,” says Carlson. “The new dry process also will get a lot of attention here in 2014 because there are quite a few states that have specifications based on mix performance. Contractors and states prove the mixes based on a Hamburg rut tester or the Overlay tester. Rubber happens to do very well under those tests.”
Smith also points out that the movement to Performance Grade (PG)nparticulate rubber binder materials, such as asphalt rubber and polymer-modified asphalt rubber, is notable. This is being worked on nationally, with many people involved. “It’s a change to traditional specification requirements concerning the dynamic shear rheometer and how that is utilized,” he says.
John D’Angelo, formerly a high-ranking official with the Federal Highway Administration (FHWA) and now the chief operating officer of D’Angelo Consulting LLC, has written a white paper that describes testing procedures needed to evaluate the performance characteristics of rubberized binders. “Without a well-defined binder specification, adoption of the use of crumb rubber modified (CRM) binders will be almost impossible to achieve,” D’Angelo writes.
“Now with AASHTO [Association of American State Highway and Transportation Officials], we’re trying to develop a regular PG spec for rubber so that more states will feel comfortable in switching over and using it,” says D’Angelo. “There are still a few issues to work out with it, but it is just about finished and ready to be approved by AASHTO. There are a lot of states that are interested and are looking at the spec.”
New testing equipment geometries are required to test CRM binders with rubber particles on the order of 1 mm in size, D’Angelo points out in his paper. “One approach that has been used in the food industries has been testing with concentric cylinder geometries,” he writes. “Dynamic Shear Rheometers currently used for asphalt testing can be adapted to use a Searle (cup and bob) system. This type of system can perform all the same type of testing that is currently used for asphalt binder grading. The advantage is that the cup-and-bob geometry can easily handle larger gaps up to 4 to 7 mm, and therefore larger crumb rubber particles.” (The cup and bob uses a center cylinder, or bob, that rotates inside the cup, which holds the binder and is stationary.)
“Initial comparisons of new testing geometry to the existing …geometry has shown that equivalent results can be obtained,” writes D’Angelo in his paper. “The testing was done on both neat and CRM binders. Preliminary testing with the new testing geometry has shown that it will provide the same results as the standard parallel plate geometry in the dynamic shear rheometer. Both coarse and fine-ground CRM binders were evaluated and provide improvements in the properties of the binder,” D’Angelo writes.
In the field: Producing, paving and bumping up the grade
Wayne Marshall, corporate quality control manager for Reeves Construction Co., Greenville, S.C., and his company operates 22 asphalt plants in Georgia. Reeves and other contractors in Georgia have successfully produced and paved more than 500,000 tons of rubberized asphalt since 2007, Marshall says, adding that there have not been any unusual performance issues with those pavements.
Reeves owns and operates several machines that can blow dry, finely ground rubber – minus 40 mesh – into a mixing drum or into a mixing pugmill located at the discharge end of the dryer drum. “Now we have the DOT behind us with specifications for it, so they wanted more control over the process,” Marshall says. “Our machines have a weigh depletion system that can measure the dry rubber.”
Marshall uses CRM binder to bump up the grade of base virgin asphalt to a typical PG 76-22. That binder is used on high-traffic state routes and interstates. Base liquid, which for Reeves is typically a PG 67-22, is taken and then enough rubber is added to bring it up to meet the requirements of a PG 76-22, Marshall says. With the latest binder, 8 percent rubber is being added to the total binder to meet DOT specs, he says. The material normally comes in 2,000-pound Super Sacks.
“If the state lets a project that requires polymerized asphalt, you can either use the PG 76-22 SBS or in lieu of that, you can use crumb rubber,” Marshall says. “The spec reads that it has to meet the same specs as the SBS [styrene butadiene styrene] polymer.”
Marshall says he and Reeves officers like crumb rubber because its price is stable, unlike that of polymer. Major projects often take a couple of years from the bid date to start of construction. So the volatile price of polymer makes it difficult to bid an asphalt paving project. If a contractor bids for a polymer project at the current price, it could easily jump by construction time. If the contractor bids an escalated price, the risk is that someone else would underbid that price.
Reeves Construction Co. has just finished a project on I-75 that has 2 inches of SMA with crumb rubber and a friction course in downtown Macon, Ga., coming north through Macon toward Atlanta. “I think we used something like 40,000 tons of rubberized asphalt out there,” Marshall says. “We use it on a lot of state routes. We have a job down in Tifton that has nearly 90,000 tons on U.S. 319 that will be laid this year. And we have a 50,000-ton job down in Albany that will be starting as soon as the weather breaks.”
On Interstate 10
In California, Granite Construction Co. recently performed a “mill-and-fill” project by milling 1/10 of a foot from a 7.5-mile stretch of Interstate 10 near Palm Desert. Granite used a gap graded Superpave mix that blended crumb rubber into PG 64-16 virgin asphalt.
The California Department of Transportation (Caltrans) requires an extender and some high natural rubber to be used in combination with the crumb rubber. The total CRM modifier was 18 percent of the binder by weight, says Jim Marsolino, project quality control manager for Granite. Virgin binder was 82 percent.
“We blended it with our portable rubber plant,” Marsolino says. “We bought the crumb rubber, the extender and the natural rubber from suppliers, and dumped Super Sacks into our hopper. That mixture goes into a reaction vessel where everything gets mixed together to make the binder. It reacts for a certain length of time based on what the spec is for the rubber. Once it reaches the specified viscosity, it goes to our holding tank, and is then used for the manufacture of rubberized hot mix asphalt.” The reaction temperature was 393 degrees.
The mixture worked well, Marsolino notes. Caltrans requires a method specification for thin lifts of asphalt instead of a density spec. Granite had to complete a certain number of roller passes at each level – breakdown, intermediate and finish stages – before the temperature of the asphalt dropped below certain levels. Steel-wheeled rollers handled compaction for each of the three stages.
“We ran the plant at 180 to 200 tons per hour, paving at night,” Marsolino says. “We paved one lane at a time, and whatever we milled out in one night had to be paved that same night.” He said the contractor was able to pave some 1,400 tons per night in an eight-hour shift.
Adds D’Angelo: “History has demonstrated that CRM binders will perform well in rutting and cracking. Using the new testing techniques, CRM binders can be compared directly to the polymer modified binders. This clearly demonstrates that CRM can be used in place of, or in combination with polymer to provide a high-quality performance graded (PG) binder.”
Reeves Wins ARTBA Award
Reeves Construction Co. recently won the 2013 Globe Award from American Road & Transportation Builders Association (ARTBA) for a project on Highway 247 in Bibb and Houston counties in Georgia. Reeves says its West Division, in collaboration with the Georgia Department of Transportation (GDOT) and Rubber Asphalt Solutions (RAS) set the green standard for asphalt paving with this project.
The project consisted of 5.18 miles of milling and repaving the existing roadway. All of the performance graded PG 76-22 binder used in these mixes was modified with ground tire rubber of up to 10 percent of the total asphaltic cement content. A total of 27,250 tons of crumb rubber modified asphalt pavement was placed across four lanes from Echeconnee Creek to Liberty Church Road through Bibb and Houston Counties, Georgia. This included a total of nearly 311,000 lbs. of processed tire rubber. All of the 12.5-mm SP dense-graded mix was produced with 24-percent recycled asphalt pavement (RAP).
Daniel C. Brown is the owner of TechniComm, a firm that specializes in communications for the construction industry.
Snow and Ice Control Equipment and Techniques for Snowfighters
From the havoc severe winter weather has wreaked this year to sustainability in action and lessons learned from other agencies, here’s a look at the latest in snow and ice control and a sneak peek at the upcoming APWA Snow Show.
By Tina Grady Barbaccia
With the extreme cold temperatures this past winter, a number of times dropping several degrees below zero, this year’s spring pavement repair and pothole patching plans will be on a greater scale than in recent years past.
Brian Anderson of the Ontario Good Roads Association and member of the American Public Works Association (APWA) Winter Maintenance Committee, says with the extreme cold temperatures, he expects to see more pavement break up in the spring because an extended timeframe will be needed for the frost to come out.
Butch Riddell, general superintendent for Kansas City, Missouri-based Superior Asphalt, agrees, noting “the winter weather conditions with their extreme warm-cold cycles will lead to accelerated changes to roads across the country. We’re already seeing damage in our local infrastructure, which will only increase with the current conditions.”
The cold weather also not only had an effect on pavements but also caused “quite a few” water main breaks in the City of Dubuque, Iowa’s distribution system, points out John Klostsermann, street and sewer maintenance supervisor for the city.
Salt brine is often applied to roadways as a pre-treatment for approaching winter weather events. This thin layer of salt brine effectively inhibits the otherwise natural bonding of snow and ice to a road’s surface. However, salt brine production can have its limitations, including cost of installing a dedicated facility: transportation of brine to satellite locations; being labor intensive to produce, changing temperatures can affect brine accuracy, attaining adequate production rates and the ability to blend in additives.
Salt brine to help cities crippled by winter weather
Some Southern and Southwestern states that experience snowfall and major ice storms this winter were “held hostage” from the inclement weather. In Atlanta, Georgia, motorists were stuck on the road for hours and children were stuck on buses and at school, without parents being able to reach them after 3 inches of snow, much of it turning to ice, totally shut down the this city with very little snow-removal equipment.
Professional-grade salt brine making, blending and truck loading systems are being used as a mobile solution for municipalities and state agencies to help prevent such a crippling situation.
Brian Evans, marketing manager for Henderson, which manufactures a salt brine, says if predictions are correct, challenging winters may become the norm instead of the exception to the rule. However, the impact of the winter events “can be greatly minimized” with technology.
“The first step is producing eutectic brine (23.3-percent salt concentration by weight)…,” Evan explains. “Next is getting the brine into truck equipment capable of applying liquid anti-ice treatments to major arteries. This should be executed prior to the winter event. Last but not least is the need to follow up during or immediately after the storm with a long-lasting application of salt slurry.”
Salt slurry is an active mixture of eutectic brine and rock salt generated inside the truck body prior to its application on a road’s surface. Instead of taking days, safe travel conditions are typically restored within 24 hours. Henderson Products is initiating an educational program with its southern distributors geared around these concepts and the equipment necessary to accomplish this.
New equipment, techniques
The City of Dubuque, Iowa’s Klostermann knows about equipment and techniques needed to keep roads safe for the motoring public. In the session, “Snow and Ice Control: Equipment and Techniques,” he will be presenting at the American Public Works Association Snow Show slated for May 4-7 in Cincinnati (apwa.net/snow) about the City of Dubuque’s basic snow and ice control operations including anti-icing, deicing and snow-removal operations, as well as share experiences and lessons learned as he incorporated new equipment and techniques into the agencies winter maintenance.
Klostermann will also address the use of blended liquid deicers for anti-icing and pre-wetting, the use of multi-edge snow plows and hi-gate wheel loader plows, along with implementing the use of an Automatic Vehicle Location (AVL) system for snow and ice control management and public information.
Sustainability in action
A wide-ranging group of stakeholders in Ohio collaborated, and in less than a year, they created a set of salt-storage guidelines – “Recommendations for Salt Storage Guidance for Protecting Ohio’s Water Resources” – for the state that met the needs and concerns of all the stakeholders. The stakeholders included highway agencies, counties, cities, townships, distributors and snow-removal companies. Recently, several salt storage piles in Ohio have been identified as the source of high chlorides in public or private ground water supplies. In fact, a village in southwestern Ohio lost its wellfield due to salt contamination, according to the according to the “Recommendations” report.
Elements of salt storage that are relevant to preventing contamination generally include siting, design and operation. When siting a salt-storage facility, accessibility to and from transportation routes such as major roadways, rail lines and/or waterways is a major consideration, along with finding a location that is central to the roads that will be treated, according to the report.
Bonus web-only reports at BetterRoads.com:“Essential Communication for Winter Emergency Preparedness” tips from Sara Croke, president of Shawnee, Kansas-based Weather or Not Inc. and “Behind the Storm – The Crucial Role of Public Works in Winter Stormfighting Fact Sheet” from the American Public Works Association.
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