February 20, 2003

Unique New Program Shows NC State Undergraduates the World of Civil Engineering

J. Alayne Westbrook (left) and Anu R. Pradhan correlate maps of New York City with GIS data to determine damage patterns caused by the World Trade Center September 11, 2001, incident. (Photo: Linda Rudd)

On a normal day, the Constructed Facilities Laboratory (CFL) on North Carolina State University’s Centennial Campus is moderately quiet, with a few experiments and material testing being performed.  But not so in December when a group of students led by Dr. Debra F. Laefer, assistant professor of civil engineering at NC State, invaded.  The students were part of an innovative program designed to introduce them to the world of civil engineering through participation in hands-on projects.

Many students have a general idea that they might like to be an engineer, but they really know very little about what engineers do all day in the real world.  Laefer has developed this program to give students a chance to do what engineers do for a couple of weeks.  “I first ran a similar program at the University of Illinois Urbana-Champaign,” said Laefer.  “It was very successful, so I wanted to try it at NC State.”

According to Laefer, “The purpose of the program is to give students the opportunity for hands-on experience, to find something in civil engineering to get excited about.”  This experience will help students decide if they want to declare a major in civil engineering, to stay in the profession and even to apply for graduate school.  In addition, they can see the practical application of what they’re learning in class.

“From our experience at the University of Illinois we found that students who have participated in this program are much more likely to find a place for themselves in the department, and they are more likely to go to graduate school,” said Laefer.

Laefer’s students, drawn from the ranks of both undergraduate and graduate students, spent their winter holiday break in the CFL, working on one of four projects.  “The students are here from 8:00 a.m. to 6:00 p.m. for two weeks,” explained Laefer.  “We work them pretty hard, but they seem to enjoy it.  The response has been very positive.”  Laefer divides the 24 students in the program into crews, each with a team leader who functions as a foreman.  The team leaders are Laefer’s regular students who have been working with her for one or more semesters — currently, two graduate students and three undergraduates.  The foreman is responsible for scheduling work, procuring materials, prioritizing and supervising the crew, just as in the real world.

Concrete blocks are tested in the alternatives-to-blasting program to discover how well chemical agents cause cracking in situations where concrete must be   demolished. (Photo: Linda Rudd)
Jet-grouted columns of soil and cement are created with varying percentages of clay contamination to determine the impact of such contamination in the in situ concrete performance. (Photo: Linda Rudd)

Four rather different projects were part of the December program. The alternatives-to-blasting project involved testing variations on old and new techniques for concrete demolition. Because both blasting and jackhammer operations are noisy, problematic ways to break up rock and old concrete, interest exists in finding quiet and economical alternatives. A traditional, although infrequently used, technique calls for drilling a hole in the concrete, filling it with water and letting it freeze overnight in cold climates; however, this technique is not very useful for North Carolina with its temperate weather. Laefer’s students are using the same principle but using chemical expansion agents instead of water. They are testing large concrete blocks to set operating parameters for the technique.

In the jet-grouting project, students quantified the negative impact on varying amounts of clay contamination in soil-cement samples, specifically testing the impact of clay on the strength of the mix-in-place, in situ concrete.  Students made cylinders with varying amounts of contamination — one, four or 10 percent — then loaded them in compression to see how well they held up compared with uncontaminated concrete cylinders.

When the World Trade Center collapsed on September 11, 2001, many surrounding buildings were damaged.  A third student group uses maps of New York City and Geographic Information Systems (GIs) to map the proximity of damaged buildings to the site.  With the computer program they can compare buildings that performed well or not as well under blast conditions.  “We will look at all the characteristics of an existing building — distance from the explosion, year built, height, number of windows and other things — to determine why some buildings were able to resist damage better than others,” said Laefer.

One of Laefer’s research specialties is assessing and correcting damage to historic structures.  The fourth project involved tensile testing of historic masonry, specifically looking at issues of post-repair performance of weakened materials such as brick or granite.  A group of students tested modern and old bricks to determine how much weight they can support.  This information could help restoration professionals determine appropriate repairs for damaged historic structures.

Student interest in the program was very strong in December, according to Laefer. “Despite lack of much publicity before the session, we had an excellent response from students,” she said. “If our program is successful and interest and funding continue, we plan to offer additional sessions during spring break and right after the semester ends in the spring.”

— rudd —

Media Contacts:         

Dr. Debra F. Laefer, 919/515-7631, debra_laefer@ncsu.edu

Linda E. Rudd, 919/515-3848, linda_rudd@ncsu.edu

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