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06.05.23 | Katherine Beach

Why Perform Special Inspections During Construction?

After a rash of structural failures leading to loss of life and property in the 1970s and early 1980s, the US government held a series of Congressional subcommittee hearings to investigate and analyze the problem of structural failures. As a result of this groundbreaking investigation, the Building Officials and Code Administrators International (BOCA) National Building Code added a new section entitled “Special Inspections”. The requirement for special inspections and identification of the types of inspections to be conducted are found in Ohio Administrative Code (OAC) 4101:1-17-01. Read More

Introduction to the Effects of Leachate Recirculation

The purpose of this article series is to explore the changes in leachate quality observed in three C&DD landfills recirculating leachate in Ohio and answer the question: Does leachate recirculation increase constituent concentrations? Read More

08.18.22 | Karl A. Fletcher

Why Freeze-Thaw Test Concrete?

Concrete may be a simple mixture, but if weather conditions are not considered for that mixture, it could be disastrous. Read More

Changes in Calcium and Magnesium Concentrations in C&D Leachate with Recirculation

In C&D debris, the dissolution of minerals from drywall and concrete contributes to elevated calcium and magnesium concentrations in leachate. Does leachate recirculation increase the concentrations of calcium or magnesium in C&D leachate? The expected answer would be yes; however, the interaction of recirculated leachate is not that simple, as our data shows. Read More

Changes in Iron and Manganese Concentrations in C&DD Leachate with Recirculation

As stated in the previous article in this series, the “Introduction to the Effects of Leachate Recirculation Series”, leachate data was compiled and analyzed using time series graphs and statistical trend testing. The time series graphs allow for a visual determination of trends. However, because there is significant variation in the data due to both natural variation and anomalous data points, visually assessing the trends can sometimes be difficult and subjective. The statistical trend testing using two methods, Sen’s Slope/Mann-Kendall slope estimator and Linear Regression, allowed for a more objective approach to determining trends. Read More