Earth Systems group of companies

Superpave Comes to California New Leadership at Earth Systems Pacific News of the Earth: Lost Continent of Atlantis Discovered? The Kitchen Sink: Text #newlingo

Fall 2013

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Geotechnical Engineering

Engineering Geology

Environmental Consulting

Materials Testing/Inspection

Contents

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Superpave Comes to California

S tarting next year, the California Department o f Transpor ta t ion

(Caltrans) will transition to a new performance-based standard for testing hot-mix asphalt (HMA). The new standard, expected to be implemented s ta te -wide July 1, 2014, is called Superior Performing Asphalt Pavement, or “Superpave.” Superpave is the product of a $150 million research program that was established in 1987 to improve the performance of roadways throughout the United States. The new standard involves a comprehensive method of designing HMA mixes that are specifically oriented to perfor-mance requirements, factoring in anticipated traffic patterns, climate, and layer locations. California now joins most of the United States and Europe in the use of Superpave. Pilot projects are currently underway at several sites in California.

According to Caltrans, the decision to transition to Superpave technology was spurred by a number of cir-cumstances, including increases in traffic loadings and volumes, changes in axle configurations, dwindling sources of aggregate, and difficulties repairing and calibrating outdated

testing equipment. Under current Caltrans specifications, pavements typically last 10 to 20 years and usually require maintenance or repair during that time frame. With the new Superpave standard, the goal is pavement with less deteriora-tion issues such as rutting, low temperature cracking, and

fatigue cracking, resulting in nearly maintenance-free pavement with a longer lifespan of 20 to 30 years.

New Test Methods and Equipment

Superpave utilizes a gyratory compactor to compact test specimens as part of the mix

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Superpave Gyratory Compactor

Earth Systems, Inc.San Luis Obispo(805) 781-0112Toll free (866) 781-0112

Earth Systems Global, Inc.Bermuda Dunes(760) 345-1588

Beijing, China(86) 10-5864-1836

Earth Systems Pacific San Luis Obispo(805) 544-3276

San Jose(408) 934-9302

Salinas(831) 422-8547

Hollister(831) 637-2133

Santa Maria(805) 928-2991

Earth Systems SouthwestBermuda Dunes(760) 345-1588

Perris(951) 928-9799

Earth Systems Southern CaliforniaPalmdale(661) 948-7538

Pasadena(626) 356-0955

Van Nuys(818) 901-8075

Ventura (805) 642-6727

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Consultant’s Corner

News of the Earth

Lost Continent of Atlantis Discovered?

New Leadership at Earth Systems Pacific

Published quarterly by Earth Systems Inc.Editor: Margaret McQuade (mmcquade@earthsystems.com or 805.544.3276)

R ecently researchers at the University of Oslo found what

they believe to be remnants of a long lost continent on the floor of the Indian Ocean between Madagascar and India. Evidence shows that the buried conti-nental crust dates from the Precambrian geologic era. Sometime between 83 and 61 million years ago, this lost continent separated from Madagascar, frag-mented, and, through the process of plate tectonics, ended up on the ocean floor. The research, led by geophysicist Trond

H. Torsvik, took place on the island of Mauritius located in the Indian

Ocean; consequently the buried continent was named Mauritia.

To piece together the continental puzzle, researchers employed gravity mapping, rock analysis, and plate tectonic reconstructions. The presence of the mineral zircon provided one of the most enlightening clues. The beach sands of Mauritius are composed of volcanic oceanic crust (basalt) and zircons, which are associated with con-tinental crust. Through radiometric dating, the zircons from Mauritius

were found to be between 660 and 840 million years old, although the island’s oceanic crust is less than 10 million years old. Researchers theorize that as magma punched through the ancient con-tinental crust on the sea floor, zircons broke off from the crust and were incorporated into the basalt lava. The lava built up to become Mauritius Island, and the zircons eventually eroded from it.

Mauritia may have been home to mammals, birds, dinosaurs, and plants. Those hoping its discovery has solved the mystery of Atlantis are destined to be disappointed, however, as Mauritia is far too ancient to have hosted Plato’s fabled lost civilization. p

E arth Systems Pacific is pleased to announce the promotion of Mr. Fred Potthast, GE, to the positions of president and chief

executive officer. A registered professional engineer in California, Oregon, and Washington, Mr. Potthast has over 30 years in geotechnical engineering and materials testing experience. He succeeds Mr. Dennis Shallenberger, GE, who continues to serve as chief geotechnical engineer and chairman of the board.

In conjunction with this transition, Ms.  Margaret McQuade has been promoted to chief operations officer. Ms. McQuade has served as executive vice president of Earth Systems for 25 years, overseeing financial operations, business development, and contract administration. p

Mr. Fred J. Potthast New president and

chief executive officer of Earth Systems Pacific

Consultant’s Corner • Fall 2013 | www.earthsystems.com

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Superpave continued from page 1

design process, and to provide quality control/quality assurance testing during construction. Components of the compactor include a rigid reaction frame, a loading system, and a device to measure the specimen height. The mixture is compacted by applying a constant load and then subjecting the sample to a gyratory kneading action. The gyratory compactor is able to compact the specimens using motions similar to those that occur during the field placement operations. The process allows the engineer to select appropriate binders, aggregate gradations, and modifiers to achieve the desired level of perfor-mance. Specimens fabricated with the gyratory  compactor are used to determine the volumetric properties (density, air voids, voids in the mineral aggregate, and voids filled with asphalt) of Superpave mixes. Those properties, measured in the laboratory, indicate how well the mix will perform in the field.

In addition to the gyratory compactor, a Hamburg Wheel Tracker is used to measure the rutting and moisture susceptibility of the gyratory-compacted HMA samples. A steel wheel weighing approximately

158 pounds is rolled across the surface of compacted HMA specimens that are immersed in a water bath maintained at a temperature of approximately 122 to 144 degrees Fahrenheit, depending upon the grade of the asphalt binder. The Hamburg Wheel Tracker measures the combined effects of rutting and moisture damage under the worst conditions expected for new pavement, such as heavy loads, hot weather, and water.

Evaluation of Rehabilitation Techniques

As the Hamburg Wheel Tracker simulates the actual conditions that traffic applies to HMA roadways, it can also be used to assist local cities and other governing agencies in assessing the use of new rehabilita-tion techniques and procedures for existing pavement. Cores or slabs of asphalt can be removed from the roadway after a renovation test strip is completed. These samples can then be tested to compare the performance of the test strip to that of new pavement or, in some cases, the existing pavement. With the resulting information, the client can make a better value assessment as to

which technique or procedure or both would produce the most cost-effective solution for their particular circumstances.

Impact on HMA Suppliers

To create a mix with a high degree of internal friction and good shear strength, Superpave mix design procedures include ref ined require ments for aggregate angularity and gradation. The design goal: a strong HMA mix that

resists rutting, yet includes enough asphalt and voids to improve durability. What does this mean for contractors working on Caltrans projects? Only higher quality aggregate will be able to meet the more stringent require-ments. Fewer sources of high quality aggregate will likely translate to higher aggregate costs for contractors working on Caltrans projects. Lesser quality aggregate will be limited to use in pavement constructed by private developers or projects under the jurisdiction of local agencies that do not utilize Caltrans funds.

Earth Systems—Caltrans Certified for Superpave Testing

Earth Systems now offers testing of HMA to the new Superpave standard. A gyratory compactor and Hamburg Wheel Tracker are currently available through our Palmdale office, which is certified by Caltrans to perform the Hamburg Wheel Tracker and gyratory tests. Samples can be submitted at any of our California locations for testing in Palmdale; additional equipment will soon be available in other Earth Systems’ locations. For more infor-mation regarding testing using the gyratory compactor and Hamburg Wheel Tracker for Caltrans projects, or to assist in value assessment of pavements, please contact Tim   Thomson at 661.948.7538 or tthomson@earthsystems.com. p

HMA specimens exhibiting rutting failure after

Hamburg Wheel Tracker testing

The Hamburg Wheel Tracker applies loads to gyratory-compacted HMA specimens

Earth Systems, Inc.895 Aerovista Place, Suite 102San Luis Obispo, CA 93401

Return Service Requested

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Text #newlingo

Consultant’s Corner • Fall 2013 www.earthsystems.com

N ew words and new meanings for existing words are constantly forming in

our dynamic language. As the Internet and social media have percolated through our culture, they have accel-erated changes in our lexicon. One of the organizations keeping tabs on language evolution is the American Dialect Society (ADS). ADS voted “google” as its word of the decade in 2009. ADS’s word of the year for 2009 was “tweet” and for 2012 it was “hashtag.” No longer just a symbol for number or pound, hashtags (#) in social media allow messages from

multiple Twitter users to be grouped together. Ben Zimmer, chair of the New Words Committee

of ADS says, “In the Twittersphere and elsewhere, hashtags have created instant social trends, spreading bite-sized viral messages on topics ranging from politics to pop culture.”

In other cases, new word forms have developed, as when the noun

“text” is used as a verb in “texting,” and when the verb “follow” is used as a noun in “thanks for the follow” on Twitter. On Facebook

“likes” are added and people are “friended” and “unfriended.” The New Oxford American Dictionary voted unfriend as their 2009 Word of the Year.

When parts or all of two words are combined, new words are formed as when “web log” blended into “blog,”

“net etiquette” into “netiquette,” and “crowd outsourcing” into “crowd-sourcing.” The latter was coined in

2006 and refers to a call to the general public to solve a problem, investigate a mystery, or fund a project or charity. Although the method has been applied for over a century, in the last ten years it has become more prevalent due to the connectivity of social media.

Acronyms that have developed from use in email and texting form new words when they are easily pronounced, as in LOL, meaning

“laugh out loud,” pronounced lawl. Taken a step further, LOL has been joined to “cat” to form “LOLcat,” an Internet meme where pictures of cats are combined with humorous captions written in “cat English.”

The Kitchen Sink

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