ALABAMA CONCRETE INDUSTRIES ASSOCIATION MAGAZINE | FALL 2014

FALL 2014

University of AlAbAmA stUdent recreAtion center | tUscAloosA, Al

FALL 2014

ConcreteWorks is a publication of the Alabama Concrete Industries Association and features articles and photographs pertaining to product applications, educational opportunities, as well as innovative construction techniques impacting the industry.

Please email rlindsay@alconcrete.org with any comments regarding featured articles in ConcreteWorks or to suggest a story idea for a future edition.

Rebecca Lindsay, Art Director & Editor John Sorrell, Editor

w w w.a l c o n c r e t e.o r gw w w.m y s a f e r o o m.o r g

TABLE OF CONTENTS

birmingham architect dick richard began his career nearly 30 years ago, and always knew he wanted to work in a field that allowed for his creative juices to flow. intrigued by the infrastructure of bridges and monuments, dick has also designed healthcare institutions using concrete.

2

The Infinitus Renewable Energy Park in montgomery was built by the conlan company of marietta, GA, which recommended concrete tilt-up construction rather than the initially proposed pre-engineered metal building. the result was a nearly 82,000 square foot facility that opened in April of this year.

10

Architect Spotlight

Energized

barry davis Architects designed the newest fire station in Clanton around the iconic peach tower, providing efficient and effective emergency response while giving visitors who approach the city from Interstate 65 and US 145 a good first impression of the city. (on tHe cover)

13 Fireproof

the new 130,000 square foot University of Alabama student recreation center brings an innovative, state-of-the-art center to the growing campus residential area, and boasts a 25,000 square foot concrete safe area for weather related emergencies.

6randall riley, executive director/engineer for the Illinois Chapter of CPA, explains how to be more cost effective when designing and constructing concrete parking lots.

18 Technical ReviewBuilt by Bama

the 2014 fall calendar will help you save all the important upcoming dates.

24 2014 Calendar

ARCHITECT S P O T L I G H T

He grew up in Birmingham, plays the guitar, and for the past 27 years, Dick Richard has been practicing architecture.

Since beginning his career in 1987, Dick knew at a young age that he wanted to go in the direction of something ‘artistic.’

“I wanted to become an architect because I felt I had some natural artistic skills,” he says. “My mom was an artist, and I loved to construct things, work with my hands and figure out the best ways to put something together.”

Dick was always intrigued by the infrastructure of bridges and monuments, and appreciates the many examples of symbolic designs across the nation, and world.

“I especially love projects that mark a moment in time and share a message about culture or technology across generations,” says Dick. “The Golden Gate

Bridge and the St. Louis Arch are examples which have become symbolic of the West in general, and their cities and people in particular.”

He also credits the ancient pyramids of Egypt for helping people understand a culture from so long ago, and modern buildings like Frank Gehry’s Guggenheim Museum Bilbao that ‘speak to our current culture and advancements in building technology.’

Aside from some of his favorite historical pieces of architecture, Dick also has some notable designs of his own that include concrete. As an associate at TRO Jung|Brannen (TRO JB), an architectural firm experienced in healthcare design, he routinely and dependably uses concrete in projects.

In one example, the firm’s 117,000 square foot Mission Cancer Center in Asheville,

RRichaRdA R C H I T E C T

ARCHITECT S P O T L I G H T

mission cAncer center | AsHeville, nc FALL 2014 3

North Carolina, featured concrete in the design in more ways than one.

“My partner, Paul Langland, who was the project manager on this project, says that the deep concrete foundations and concrete retaining walls were essential to our plan for the entire project. Paul remarked that no other material can retain earth like concrete; some walls on this project are as tall as thirty feet high,” said Richard.

Langland and his team were faced with a complex, sloping site that required substantial retaining walls in various locations on the site, most prominently supporting a 25-foot waterfall feature, seen from the highway. Concrete was the obvious choice to advance the structural

design of those walls. While the waterfall, itself, was adorned with a decorative, locally-harvested granite face and stone frame to represent material found in the regional Appalachian Mountains (an important factor in the project’s ultimate LEED Gold certification), it was concrete that supported the structure from behind and made the iconic architectural water feature possible.

In another application on this same project, concrete walls up to eight feet thick were used, which is not unusual in cancer center construction.

Together, those thick walls, constructed in both vertical side wall and horizontal floor and ceiling applications, form vaults which act as a shield for the highly radioactive

TOP: Mission Cancer Center exteriorBOTTOM LEFT: Black bear lying on concrete wall outside of Mission Cancer Center

ARCHITECT S P O T L I G H T

beams produced by the linear accelerator equipment. To soften the building’s exterior where the concrete vault was located, TRO JB’s team developed an adjacent greenspace and Bocce Ball court there.

The resultingeffect is quite welcoming, maybe too much so. Even the larger local wildlife, shown napping on one of the concrete walls, approved.

“Concrete is also a material we use when designing parking deck projects, which we have designed for many of our hospital clients,” Dick says. “We’ve even used decorative, precast, concrete panels for our parking deck which supports the Mission Cancer Center. The material can be utilitarian, cost effective, and design-enhancing, at the same time.”

Dick credits concrete’s natural beauty and economic benefits, and the fact that it can be formed or stained to create a multitude of appearances, or it can just be natural and evoke a sense of strength and durability.

“When you use concrete, you know it’s going to be there a long time,” he says.

Just like some of his favorite ancient buildings that recognized the lasting value of stone based materials.

about tRo Jb

TRO JB is an integrated planning, architecture and engineering firm, founded over a century ago to provide design services for healthcare institutions. The firm is guided by a commitment to create exceptional and responsive design, using leading-edge technology to develop projects that perform beyond client

expectations, and prides themselves on building long-standing collaborative relationships with our clients and partners.

Its success is the result of consistently building the best team for a given project – a custom team comprised of knowledgeable architects, interior designers, engineers, and planners with specific expertise matched to client needs. Its staff experience and portfolio feature concentrations across several sectors: corporate and commercial development, research and life science, and our deep expertise in healthcare design.

TRO JB’s healthcare practice encompasses hundreds of clients over the years with construction projects totaling more than ten billion dollars. Its award-winning experience includes new construction and renovation projects ranging from clinics and community hospitals to academic medical centers in urban areas worldwide. Many clients today rely on their expertise in lean practices and alternative project delivery methods.

As an international practice, TRO JB has an extensive portfolio of projects throughout the United States, the Middle East Gulf Region and Asia.

Get to Know

dicK RichaRd

What are your hobbies? I love to read and study the Bible, play tennis with my friends, take walks with my wife, travel and do projects around the house. I also enjoy going out to Oak Mountain to hike or bike with my wife. Occasionally I’ll go mountain biking with my son as long as he doesn’t want to do the “Blood Rock” trail.

What’s the last book you read? The Atonement Child by Francine Rivers

What’s your favorite food? There’s not much I don’t like in way of food, which is why I need to stay disciplined about exercising. If I had to pick something, it would have to be a nice filet mignon cooked medium rare with homemade soppage (made from a little olive oil, a few spices and some of just about everything in the refrigerator door). Put that alongside some good fresh veggies, some of Deb’s homemade rolls, a nice glass of wine and share it with family and friends, that’s what I’m talking about.

What is your favorite thing about your profession? Being a part of the creative process and seeing something you design and create become a built reality.

What is the one tool you can’t live without? My mind

ARCHITECT S P O T L I G H T

FALL 2014 5

P R O J E C T S P O T L I G H T

BUILTby

BAMASituated between the towering student housing buildings, the new 130,000 square foot University of Alabama Student Recreation Center brings an innovative, state-of-the-art center to the growing north campus residential area, which houses several thousand students.

A classical exterior of brick and precast concrete that fits the central campus traditional appearance, wraps an exciting, modern interior shared by recreation

space, an administrative program, a food service venue, and an impressive storm shelter for 3,000 people.

Designed by TMP Architecture and Williams Blackstock Architects, the project was planned in two stages, which included a five-month programming study and a nine-month design and working drawing production phase. Juneau Construction Company excavated rock and constructed the facility in 21 months,

concurrent with the adjacent Presidential II Student Housing project. “The Student Center has a unique location on the north bluffs of the campus which overlook the Black Warrior River,” says Binx Newton with Williams Blackstock. “The building design takes advantage of the height by stacking three stories of amenities with views through the treeline and to the river activity beyond.”

University of AlAbAmA stUdent recreAtion center | tUscAloosA, Al

P R O J E C T S P O T L I G H T

FALL 2014 7

ExPAndEd And RESToREd PUBLIC SAFETY BUILdInG | MonTGoMERY, AL

P R O J E C T S P O T L I G H T

The skylight-capped atrium is the main space onto which all of the major spaces are organized. Student fitness, strength, and conditioning spaces, a three-court gymnasium, a training facility for the UA Rowing Team, food service, administrative office spaces for Housing & Residential Life and Parent Programming, and a central space with a 40-foot tall climbing tower and wall are connected along a grand organizing spine that provides transparency and depth of natural light throughout the facility from the two-story entry hall to the huge covered patio.

KEEPInG THE CAMPuS SAFEA secure 25,000 square foot storm shelter designed using FEMA guidelines is integrated into the basement, making it extremely accessible for the students, faculty, and staff in the north campus.The design team worked closely with the

University to identify the performance goals for the storm shelter, in concert with the FEMA 361 and ICC 500 guidelines. While some hazardous events can last longer, the design goal was to create an easily accessible central gathering area amongst the housing district to make students, faculty, and staff safe during tornado events, which typically last only hours.”

“Since the shelter was part of a larger facility we had to design a place that 3,000 students would be safe not only from the storm but from the rest of the building, and this was achieved by separating the basement from the upper floors with 20 inches of concrete, allowing the sports and recreation floors of the building to collapse above the shelter, while keeping students safe,” says Newton. “These spaces are supported with emergency

TOP LEFT: University of Alabama Student Recreation Center constructionBOTTOM LEFT: University of Alabama Student Recreation Center interiorBOTTOM RIGHT: University of Alabama Student Recreation Center exterior

P R O J E C T S P O T L I G H T

power for mechanical systems and phone charging, and for storage of emergency supplies. The hardscape and topography were shaped to allow several thousand people to quickly access the storm shelter in an emergency situation.”

Additional design features include provisions for stand-alone emergency power around the generator and fuel supply, stand-alone mechanical systems, and storage for emergency supplies.

WHy uSE COnCRETE?Concrete was chosen to not only achieve a monumental appearance, but to express the juxtaposition of dense safe spaces with wide open sculptural spaces.

Concrete enabled the expression of strength with a simple structure with dramatic features. The visible, functional concrete columns, beams, and walls throughout the facility informed the overall aesthetic of the interior design,

and established a basis of a cool, neutral palette that is warmed by natural light and accented by dramatic warm color features.

The architectural qualities of exposed concrete provide a refined and heroic design aesthetic that lends itself to institutional and public buildings,” says Garrett Goodman, University of Alabama student architect. “For the Student Center, the University wanted to create large and dramatic spaces that were welcoming to thousands of students, faculty and staff on a daily basis, and from structural performance to a monumental design aesthetic, concrete was the perfect choice for the building” The entire building, except for the long span steel joints over the gymnasium, features a concrete frame, including foundations, below grade walls, thickened slabs, columns, beams and floor systems. In addition, three-story concrete columns on

concrete pedestals are a major feature of the classical exterior of the building, along with precast cornices, lintels, and bands. With an emphasis on natural light and creating large, welcoming spaces, the exposed concrete finishes provide a monumental feel for the facility,” says Garrett Goodman, University of Alabama student architect.

Whether it be in the strength of function or the appearance of permanence, concrete is versatile. For this structure, the density, durability, and fire resistance are critical for the protection of thousands, while the ability to shape it into any form are important for creating subtle curves and dramatic spaces.

FALL 2014 9

InFInITUS REnEwABLE EnERGY PARk InTERIoR | MonTGoMERY, AL

P R O J E C T S P O T L I G H T

FALL 2014 11

This past spring, a revolutionary Materials Recovery Facility (MRF) developed by Infinitus Energy opened in Montgomery, with the main purpose of eliminating up to 85 percent of waste headed to the city’s landfill.

The Infinitus Renewable Energy Park at Montgomery (IREP at Montgomery), is located at 1551 Louisville Street, and is the first facility to combine several of the most technologically advanced systems available for waste recovery to create the most advanced integrated waste recovery facility in the country.

J.R. Miller & Associates, Inc. (J.R. Miller), an architect and engineering firm who has planned and design over seventy transfer stations and materials recovery facilities, was commissioned to develop the building layout and overall site plan. In addition, Bulk Handling System (BHS), the equipment provider, was requested to provide an equipment layout to determine the impact of their equipment on the building and adjust the building footprint to accommodate the proposed equipment processing line design.

With their combine expertise, a criteria set of drawings was created with the building layout and details, along with the overall site layout.

“Construction of the 81,992-square-foot facility took about 10 months, and contains enough steel to build 466 cars,” says Angel Mendez, chief operating officer of Infinitus Energy.

But steel wasn’t the only component. The project was a design-build contract, and the awarded general contractor, The Conlan Company of Marietta, GA, recommended

concrete tilt-up construction rather than the initially proposed pre-engineered metal building to reduce cost and the duration of the building construction.

The architectural and engineering phase started in February 2013, and construction of the site, building, and equipment package commenced in July of that same year, and was completed in April 2014.

“So much concrete was used that you could extend a five-foot wide sidewalk 44-plus miles,” he says. It took almost 70 truckloads to transport Bulk Handling Systems’ equipment to the facility, and at the recommendation of the design-build contractor, we made the decision to use concrete due to a reduced cost over the metal building, shortened construction schedule, and increased life.”

The original parking lot was designed in asphalt, but the decision was made to switch to concrete due to the amount of traffic, soft existing soil conditions, excessive rain during grading operations, reduced maintenance costs and overall durability.

“In addition, the weight of the materials handling equipment and rolling stock , in conjunction with the existing soil conditions, led us to choose concrete pavement around the exterior of the facility and a10-inch, double mat reinforced concrete slab for the building,” says Mendez.

Now that the facility is operational, residents can place all trash in one city-issued bin, which is collected by the city of Montgomery sanitation department, and taken to the Advanced Mixed Materials Recovery Facility at the Renewable Energy Park.

energized

P R O J E C T S P O T L I G H T

“So much concrete waS uSed that you could extend a five-foot wide Sidewalk 44-pluS mileS”

InFInITUS REnEwABLE EnERGY PARk InTERIoR | MonTGoMERY, AL

There, it is separated using the latest in screening, air and optical separation technologies. The system sorts and recovers commodities such as cardboard, mixed paper, metals, aluminum cans, plastics and wood based on density, size, shape and material composition.

Additional sorting will be done by hand at the site. The advanced technology allows the facility to accept a larger variety and volume of potentially recyclable products than other recycling methods.

Mendez says his favorite part of the building is the overall architectural design and entry feature, and the use of concrete panels allowed the architect to design recesses, texture and depth not found in metal buildings.

“We had a short construction schedule and a long-term contract with the city of Montgomery to provide waste processing to recover recyclable materials, so we

needed to design a building that could be constructed quickly, be durable and have reduced maintenance costs,” says Mendez. “Using concrete was an obvious choice.”

additional featureS of the building 108 sky lights to reduce the amount of overhead lighting required Exterior odor control system 2,420 sq. ft. equipment pit with a 24” foundation and a volume larger than an Olympic size swimming pool Processing equipment has approximately 144 motors Facility (building and site) has enough concrete to build a 5’ wide concrete sidewalk 44 miles long

why uSe concrete for parking lotS? (source: NRMCA)

The “first cost” price benefit of asphalt compared to concrete has been eroding steadily in recent years and disappeared entirely in many areas during 2008. This trend is explained in part by asphalt’s petroleum-based composition and the impact of long-term oil price increases. But another important factor is that refiners are increasingly producing more profitable fuels and other compounds from the barrel of oil resulting in reduced liquid asphalt availability—a trend that is expected to accelerate in the future. This is why asphalt prices have remained high with ongoing shortages in some areas even after the collapse of oil prices at the end of 2008. Concrete offers ample supply and price dependability for the future. Normal maintenance costs of asphalt pavements-sealing, re-striping, resurfacing, and loss of business during maintenance operations-greatly exceed those needed for concrete. Click here for a real-world example of the penalty associated with asphalt maintenance downtime. Concrete increases curb appeal for customers and tenants, boosting rental values and revenue. Concrete parking areas may include an integral curb and gutter, saving time and reducing subcontract labor. Concrete parking lots stay cooler to reduce energy costs.

FALL 2014 13

P R O J E C T S P O T L I G H T

FireprooF

When the city of Clanton, AL, approached Barry Davis Architects to design its newest fire station around the iconic peach tower, the firm knew it had to complement this iconic landmark in Chilton County, while providing efficient and effective emergency response, giving visitors who approach the

city from Interstate 65 and US 145 a good first impression of Clanton.

“We were given a very prominent site at the base of the Peach Water Tower, a source of pride for Clanton and Chilton County, and part of our design included enhancing the illumination of the water tower,” said Barry Davis. “The facility also serves as the command and control center during emergencies.”

The firm spent four months designing and preparing the project, and construction took 18 months to complete.

“We designed the facility around the apparatuses that it must house, and the emergency responders who must quickly

deploy from the facility,” says Barry. “Our primary objective in planning the building was to allow men and women to move easily from the day room or dormitory through the room storing their turnout gear to their vehicles, and then allow the apparatuses to move easily to the street.”

The control center is situated to provide clear visibility of the entire front of the facility as well as the apparatus bays. All other support functions – hazardous materials

decontamination, maintenance, storage, etc. – are immediately adjacent to the apparatus bays.

Secondarily, the building is arranged to provide an inviting center for community activities. When not fighting fires, the men

and women stationed here may offer free blood pressure checks or install children’s car seats. Ample parking is arranged around the easily recognizable “front door”, encouraging citizens and visitors alike to take advantage of these services or simply drop by for a tour.

“When we were designing the facility – building and site – its character was as important to us as its function, and we carefully selected the materials – jumbo

F E A T u R E

FALL 2014 15

brick, split face concrete masonry unit (CMU), cast stone, standing seam metal roof, concrete, and the planting materials – to evoke a sense of permanence and civic pride,” he says. “We used colors, textures, and scale that are consistent with other civic buildings we have designed for the City of Clanton, and our objective was to reflect the character of a growing seat of a rural Alabama county while complementing the Peach Water Tower.”

Of course, concrete was one of the main components used to construct the fire station, mainly for its strength, durability, and permanence.

“We used architectural cast-in-place concrete columns at the entrances to

convey the character of the building, which will also keep a vehicle from driving through those doors,” says Barry. “In addition, concrete provides shorter lead time than structural steel, and doesn’t require painting or other maintenance. Not to mention, it is inherently fire-proof.”

Load-bearing masonry gave the facility durable, easily maintained walls throughout, which included the liberal use of water in the apparatus bay. Using this masonry made it simpler to provide the requisite two-hour separations between the apparatus bay and the living and business areas.

The concrete parking lots are also a conversation starter, since fully-loaded fire trucks are very heavy, and many asphalt

parking lots fail under such loads.

“We knew from the inception that we would use concrete for the apparatus bays (8” thick reinforced with #3 bars) as well as for the drafting pit, so we already had a significant amount of concrete in the project.,” says Barry. “It made sense to us to take care of all of these with a single trade. Using concrete, we were able to have cleaner details where these and other elements abut.

Additionally, the plastic nature of concrete made it easier to address the drainage problems around the site without adding drainage structures. As an environmental concern, concrete reduces the “heat sink” affect around the building while increasing the amount of reflected natural light into the

F E A T u R E

“We were given a very prominent site at the base of the peach Water Tower...”

clAnton fire stAtion nUmber 3 exterior | clAnton, Al

apparatus bay. The parking and circulation areas used by the fire trucks are 6” thick reinforced with welded wire fabric and fiberglass fibers for maximum strength.

project Team: Architect: Barry Davis, Architects, P.C. Barry Davis, Principal in Charge / Olivia Davis, Project Management & Interiors / Kevin Kempke, Intern Architect Structural Engineer: LBYD Civil & Structural Engineers Mechanical Engineer: Southern Engineering Consultants, Inc. Electrical Engineer: Jackson, Renfro & Associates General Contractor: Clements Dean Building Co., LLC

FALL 2014 17

projecT Quick FacTs:

• $180 per square foot includes extensive site work. A large part of this is the drafting pit – a structure that, for practical purposes, must be constructed of concrete – that cost approximately $70,000. The use of concrete is quite economical, and probably did not increase the cost.• In addition to the basic elements of a firehouse (two 77’ deep apparatus bays; dormitories for eight men and two women; control center; day room; turnout lockers; dining), the facility includes:• Two concrete/cmu safe rooms• Gas-fired radiant heat strips for energy efficiency in the apparatus bays;• An emergency generator• A separate office that serves as police depart annex, task force headquarters, command/control center, etc.• A 20’x30’x10’ deep concrete drafting pit• A hazardous materials decontamination room.

F E A T u R E

F E A T u R E

Birmingham Fire sTaTion no. 18Constructed of modular brick with concrete block back-up, the No. 18 fire station in Birmingham is a one-story facility highlighted with brick accents and precast concrete. The exterior features shingled hip roofs, a dry stack stone entrance tower, a tower over the middle apparatus bay, and a continuous precast bull nose around the front elevation. The building, which took seven months to design and 10 months to construct, also includes a concrete parking lot to minimize the maintenance of resurfacing.

“The building was designed with residential features to fit within the residential context,” says Clay Dorsey with Dorsey Architects. “The facility is well landscaped and has an architectural keystone designed retaining wall at the rear.”

Concrete was used concrete in certain areas for its durability and maintenance, and for its ability to withstand the heavy loads of trucks and equipment. The construction

consists of concrete masonry unit (CMU) backup with FBX modular brick veneer for the exterior and all CMU wall partitions for the interior because of sound transition, durability, maintenance and long term cost savings. The exterior and interior walls of the building are 100% CMU.

The new structure also includes a safe room, which was a relatively simple design plan for the firm since all of the walls were CMU block and filled with concrete throughout.

“We just added the required size re-bars in all of the cells around the safe room area, and provided a reinforced concrete slab above the ceiling area,” says Dorsey.

The project cost $220 per square feet, and came in under budget.

project Team: Architect: Clay Dorsey Consultants: Civil Engineering Design

Technologies Inc. Structural Engineer: MBA Group Mechanical Engineer: Engineering Design Technologies Inc. Electrical Engineer: Sajjadieh Engineering Group, P.C. General Contractor: Civicon General Contractor

T E C H N I C A L R E V I E W

InTROduCTIOn

In the “old days” (prior to 2008) we were forced to sell concrete parking lots based primarily on long-term costs savings, or so we thought. We would perform life cycle costs analyses showing those savings to engineers and owners and anyone else that would listen. We would tout the longevity of the product citing examples of concrete structures from the days of Jesus Christ. Short of offering our first-born, we would resort to any means of selling concrete pavement advantages only to have the first-cost issue thrown back in our face. We thought we were just fighting price but perhaps we were really fighting our own lack of education.

Various economic factors have driven asphalt prices higher so now we believe we can finally face first-cost competition head-on. According to Randell Riley, P.E., executive director/engineer for the Illinois Chapter of ACPA and consultant to Illinois Ready Mixed Concrete Association, we’ve always been able to do this, yes, even in the “old days.” Below is a reprint of Randy’s article entitled “Inch

by Inch” explaining why we always had the

option to be cost competitive on concrete parking lots. Randy cites examples from the Illinois Department of Transportation, but frankly the example is apropos for most any state as Randy uses AASHTO 1993 Guide for Design of Pavement Structures as the basis of his discussion.

At NRMCA we endorse use of ACI 330. The Guide for Design and Construction of Concrete Parking Lots as the first option for concrete parking lots. The Guide and associated specification offer an all-inclusive approach to design and construction. Often engineers cite use of AASHTO 93 as their design choice because they feel there is some comfort in using the same source as their DOT. We feel there are many smarter reasons to use ACI 330 instead, but I will leave that for another discussion ( or Webinar, see below). When dealing with engineers and designers that refuse to move away from AASHTO 1993 in designing their concrete parking lots, Randy’s article might do just the trick in getting a reasonable specification.

InCH By InCH

I’d like to take a couple of minutes of your time to show you how concrete has always

been first-cost competitive if you were designing the sections to actually carry roughly the same traffic and getting the same life. Let’s take a typical Illinois parking lot pavement section. How many of you have routinely seen a section of 3-inches of bituminous surface on 6-inches of granular material? How many of you have seen even less? How many inches of concrete would it take compared to what the engineers and architects frequently pull out of their mysterious design manual? And why? Let’s start with the why.

Most engineers and architects start one of two places in Illinois: either Chapter 54 of the Illinois Department of Transportation’s (IDOT) Bureau of Design and Environment Manual (BDE Manual) for highways or Chapter 37 of IDOT’s Bureau of Local Roads Manual. (BLR Manual) Are these really appropriate for parking lots? Probably not! IDOT designs for controlling vehicles that are principally trucks – and usually a lot more than we are inclined to see on a typical parking lot.

For example, if you look at either of these references they start at the bottom traffic levels with about 12 percent truck traffic. There are provisions if you know what you

Inch by Inch InTROduCTIOn By AMy MILLER, nATIOnAL RESOuRCE dIRECTOR, nRMCA - ARTICLE By RAndELL RILEy, P.E . , ExECuTIVE dIRECTOR/EnGInEER FOR ILL InOIS CHAPTER OF ACPA And COnSuLTAnT TO ILL InOIS REAdy MIxEd COnCRETE ASSOCIATIOn

SUMMER 2014 19FALL 2014 19

T E C H N I C A L R E V I E W

are doing to go below this level, but even then the minimum thickness for concrete from the design charts in the BDE Manual is currently about 7.5 inches for soil conditions typical of parking lot construction and 6.5 inches for the BLR Manual. Both procedures are mechanistically based and incorporate extremely high levels of reliability. Both also imply that granular sub-base is “optional” at traffic levels typical of parking lots, but explain “optional” to most engineers and the word “required” seems to take its place.

What about the asphalt designs? What are the minimums there? The BLR Manual says 3 inches on 8 inches of stone is adequate. So how do you actually compare these competing sections? Clearly, IDOT methods are not the answer!

There are a number of competing design systems for concrete pavement in this design niche. Many of you are familiar with the Concrete Pavement Analyst (CPA) software available from National Ready Mixed Concrete Pavement Association. It has been discussed on several occasions at the IRMCA annual short course and seminars have been conducted on its use by your association. CPA is largely based

on a variation of the results of the road test conducted by the American Association of State Highway Officials (AASHO). I will not go into detail here, but CPA uses a variation on the structural coefficient approach to assign a structural coefficient to concrete.

However, since the AASHO Road Test was conducted right here in Illinois, why not use the data, the methods and the equations laid out in the 1993 Guide for Design of Pavement Structures? If it is meaningful anywhere, it should be here in Illinois.

First, a little history. The engineers at the Road Test conducted testing on sections of both asphalt and concrete pavements under the same traffic loadings at the test site west of Ottawa, IL. Interestingly, some of these sections included loadings restricted to automobiles and light trucks; loads more typical of convenience store and mall parking lots. The concrete thicknesses on these sections ranged from 2.5 inches of concrete up to 5 inches. How did they fare? One of my personal favorites, an out of print publication, Pavement Performance in the National Road Test, produced by Portland Cement Association in 1962 offers some insight.

The tables above demonstrate how the pavement sections performed. The tables area little busy, but they are jampacked with exciting information for pavement geeks interested in promoting concrete pavements for parking lot applications. During the Road Test vehicles ran over the traffic loops until the loops had received roughly 1,114,000 axle load repetitions or the pavement section had failed. Periodically, engineers at the Test Road would evaluate the “serviceability” of the sections on a 5-point scale, five being a smooth pavement in new condition and 1.5 having been determined to be failure of a section in need of serious repair. The vehicles ran in adjacent lanes restricting the specific loads to those lanes. In our table you will see that one lane operated with 2,000 lb. axle loads; the other with 6,000 lb. axle loads. By conducting the test in this manner is was possible to compare performance of different loads to one another while simultaneously evaluating the affect of those loads on different pavement sections. The asphalt and concrete pavements of different sections received identical loadings under identical traffic for roughly two years.

The tables as laid out depict the service-ability after 1M plus axle loads shown as a

FALL 2014 21

grade ranging from 1.7 to 4.4. If the section failed, i.e. reached a serviceability of 1.5, the number of axle-load repetitions in thousands is shown. In addition, various subbase thicknesses were evaluated for both asphalt and concrete. For concrete sections mesh-reinforcement was also evaluated as that was popular at the time of the test. (Mesh-reinforcement turned out to not make a difference, but that is perhaps an article for another time. Needless to say, we no longer use mesh in Illinois.) Let’s work left to right for the concrete section of Loop 2 and the 2½-inch concrete pavements. Yes, they tested them that thin. Serviceability of the pavement sections for 2,000 lb. axle loads similar to that of an automobile were in very good condition, i.e. serviceability greater than 4.0 after 1M plus repetitions. This was regardless of whether the pavement was placed directly on Illinois’ marginal soils or with 3 inches or 6 inches of stone subbase somewhat similar to today’s dense-graded granular CA-6 with a fairly high amount of fine material.

The 6,000 lb. axle loads pounded the section a little harder, but even here the 2 ½-inch concrete section still carried about 469,000+/- axle load repetitions. The stone helped some on these very thin sections. What about the asphalt sections? They were tested under the same traffic and same weather conditions. Indeed, these were loops so the trucks ran on concrete on one side and asphalt on the other. Looking at the table we find some interesting comparisons.

From top to bottom on the asphalt section of the table it shows the thickness of the asphalt surface. The “base” and “subbase” as defined at the Road Test are a stone base and sand-gravel subbase; in simple terms, all basically granular material. For

3-inches of asphalt on dirt carrying the rough equivalent of automobile traffic the serviceability of the asphalt was 3.0 at the end of the test. This compared to 4.3 for the 2½-inch concrete section under identical conditions. A fluke, right? How about the 6,000 lb. axle loads?

Careful inspection of the 6,000 lb. data indicates that for the same conditions described in the previous paragraph, the 2½-inch concrete pavements carried greater than five times the number of repetitions to failure as that of the 3-inch asphalt section. Checking the tables carefully you will find that in general inch for inch, the concrete outlasted the asphalt!

So, back to the original question; how would the sections compare using IDOT standards that an architect or engineer might pull off the shelf and use? The chart on page 19 shows the answer. The concrete sections, either the minimum that we normally recommend for parking lot section drives with low truck traffic or the IDOT section will carry significantly more traffic than the minimum IDOT bituminous section.

Next time we can use some of these relationships in the current competitive climate to prove why concrete has always been first-cost competitive if you can get an equivalent design.

So there you have it. If you are promoting concrete pavements, particularly parking lots, it is very important to understand this article. ACI 330 should be our first source for concrete parking lots, but in the event we have an engineer refusing to use anything but AASHTO we should point to the data that came from the actual study (i.e. 1.1 million repetitions of a 2K lb axle load over 2.5” over concrete with NO subbase and a

terminal serviceability of 4.4! Wow!). Also, in my Webinar I refer to Low-Volume Road Design Table 4.9 in AASHTO 93. Even at thickness estimation using these charts from the manual the thicknesses are well below what some engineers use that are citing AASHTO 93 as the source of their design.

For more information, contact Amy Miller at amiller@nrmca.org. Amy presents monthly a Webinar entitled “ACI 330: The Gold Standard for Concrete Parking Lot Design and Construction.” The Webinar delves into reasons why using ACI330 as opposed to the AASHTO 1993 Guide is most beneficial for owners and designers among other topics related to the ACI 330 document.

Contributing author Randall Riley is the executive director/engineer for the Illinois Chapter – ACPA, and a consultant to Illinois Ready Mixed Concrete Association. He is actively and enthusiastically involved in the day-to-day building of partnerships and promotion of long-life quality concrete pavements. He can be reached at 217-793-4933 or at pccman@ilacpa.com.

T E C H N I C A L R E V I E W

M E M B E R n E W S

ConCrete representatives Meet with Gov. Bentley

On June 16, representatives from the Alabama Concrete Association, Alabama cement companies, ready mix producers and the Southeast Cement Association met with Governor Robert Bentley.

The meeting was held at Brasfield and Gorrie in Birmingham, with its main purpose being the discussion of the increased use of concrete products in Alabama through concrete paving options and the importance of green building to the state, as well as the detrimental effect of anti-LEED legislation.

In addition, the meeting helped raise funds

for Gov. Bentley’s reelection campaign, in which ACIA contributed $5,000.

ACIA Works with ALDOT to Increase Yardages for Bridgemasters In June, the Alabama Concrete Association was successful in working with the Alabama Department of Transportation.

(ALDOT) to increase the yardage a concrete truck featuring a bridgemaster could deliver to an ALDOT project. Under the new regulations, bridgemaster trucks are now able to deliver 8.5 yards instead of the previous 7.5 yards.

Based on testing by member companies and ALDOT, 8.5 yards maximized the average truck’s weight while still meeting the bridge formula for maximum weight of 66,000 pounds at 36 feet on the interstate system. The allowance of 8.5 yards will cover most trucks, but if your company has a vehicle that you believe could haul additional yardage, please contact the association.

The ACIA is working with ALDOT to develop a system to address older trucks which have a lighter empty weight due to more lenient emissions requirements in the past.

ConcretenewsF a l l 2 0 1 4

new MontGoMery hiGh sChool reCeives national reCoGnition

Montgomery’s new Park Crossing High School was featured this month as part of an exhibition at Washington D.C.’s National Building Museum.

The school features storm shelters designed by Alabama architectural and design firm Goodwyn, Mills and Cawood that can protect students and teachers from winds up to 250 mph. An entire storm shelter just like the ones at Park Crossing was set up inside the museum.

M E M B E R n E W S

ButCh wyatt ConCrete Cup

The Alabama Concrete Industries Association recently hosted its 4th Annual Butch Wyatt Concrete Cup, which was held in appreciation for architects and engineers who are proponents of designing with concrete products. The event took place at Inverness Country Club in Birmingham on Monday, September 29, with more than 80 architects, engineers and industry representatives participating in the ACIA sponsored event.

First Place Team: Gene Kelley (McKee

& Associates), Darren Hamrick (Sain Associates), Steven George (Cemex) & Frank Conn (Conn Ready Mix).

paC update

The PAC has reached 95% of its goal of $25,000. Currently, $12,033 was raised through our materials auction, and an additional $6,685 on the silent auction and gun raffle at the 2014 Annual Convention.

This year, we contributed $11,000 to Senate candidates, $14,000 to House of Representative candidates, $1,500 to statewide races, and $5,000 to Governor

Bentley’s campaign. We also contributed to 15 Senate candidates and 33 House of Representative candidates. Of these contributions, only one candidate lost in the primary election.

Adding in the $5,150 we raised through contributions on our annual billings, our current total is $23,868. With a little more work, we will meet or exceed our goal.

TOP: First place winners (L to R: Frank Conn, Gene Kelley and Steven George; not pictured: Darren Hamrick)

SUMMER 2014 23FALL 2014 23

-05

2 0 1 4 C A L E n d A R

14JAN.ACI/CT CertificationACI Level 1 is a two-day only program that will consist of classroom review followed by a written test and hands on performance test. Concrete Technology (CT) is a one and a half day course addressing regulations of concrete as required by the state. After successful completion of this class, state employees will be qualified to run testing procedures to determine the quality of the concrete. There is a written exam for this certification. To register, visit www.alconcrete.org/classes.

02DEC.2015 Annual MeetingThe Hyatt Regency (formerly Wynfrey Hotel), Birmingham

Speakers: TBD

-05ACI/CT CertificationACI Level 1 is a two-day only program that will consist of classroom review followed by a written test and hands on performance test. Concrete Technology (CT) is a one and a half day course addressing regulations of concrete as required by the state. After successful completion of this class, state employees will be qualified to run testing procedures to determine the quality of the concrete. There is a written exam for this certification. To register, visit www.alconcrete.org/classes.

ACIF Pheasant Shoot9am & 1pm, Whitetail Adventures of Alabama - Oneonta, AL

This fundraiser will help raise money for two $8,000 scholarships. To register visit www.alconcrete.org

MARK ITDOWN2014

13

04NOV.

NOV.

Building the World Around You

Alabama District (205) 969-2629

It’s not just what we make,it’s what we make possible.®

www.martinmarietta.com

Martin Marietta Materials

C

M

Y

CM

MY

CY

CMY

K

AL Concrete 6-17-14.pdf 1 6/17/2014 12:46:39 PM

PRSRT STdU.S. PoSTAGE

PAIdmontGomery, AlPERMIT no. 77

1745 Platt PlaceMontgomery, AL 36117www.alconcrete.org334.265.0501

2015

AnnuAl Meeting

Wednesday, January 14, 2015The Hyatt Regency (formerly Wynfrey Hotel), Birmingham

Speakers: TBD

2015 ACIF Scholarship Recipients2015 Chairman Award Recipients

*Invitation and additional information to follow