POLAND, Ohio - Back in July, 21 News reported on structural concerns with the Poland Library. Now, the Public Library of Youngstown and Mahoning County (PLYMC) is providing an update on what's going on and whether or not the library is safe.

According to a press release, engineering firm Geotechnical Consultants Inc (GCI) were called to investigate. Their investigation revealed portions of the concrete floor slab along the southeast side of the library were experiencing heaving.

GCI drilled holes through the slab to determine the composition of soils below. Holes drilled in areas of significant heaving encountered slag-based fill materials, while holes drilled in areas not experiencing any uplift found stable and natural soils below the floor.

GCI issued the following statement:

"In the Mahoning Valley, slag (steel or ferrous slag) was historically produced during steel production. Over the years engineers and design professionals have learned that the chemical properties of slag give it the potential to expand, which can sometimes lead to detrimental impacts on structures. Slag expansion has been attributed to pavement failures, tilting of walls, and heaving of floor slabs, sidewalks, and building foundations. Unfortunately, risks associated with slag are often unpredictable, and the properties that make some slag expansive can last for decades following its production."

"Slag samples obtained during the drilling process at the Library were tested for expansive properties and found to be readily expansive. Based on this, it is GCI's opinion that the floor slab heaving occurring at the Library is the result of expansive slag below the floor. Extensive research has been done to develop techniques to eliminate the expansive properties of slag encountered on building projects; however, these studies have not been able to produce reliable, long-term acceptable results to prevent its expansion. The only proven method to remediate slag expansiveness is to remove it from problem construction areas."

PLYMC spokesman Michael Stepp is assuring patrons and staff that the library is safe to use while architectural review continues.