Durability of Cement-Based Materials

Although cement-based materials such as concrete are widely used in the construction industry, we are still facing important durability issues. Corrosion of reinforcement in concrete due to chloride exposure, Alkali-silica reactions, freeze-thaw damages are some examples of durability issues decreasing the service life of structures and increasing their life cycle costs due to increased maintenance and rehabilitation.

Recent and Current Research

Flowable Fill Containing Quarry Limestone Quarry Fines as a Backfill Material

Principal Investigator(s): Ceki Halmen, Ph.D.
Funded by: University of Missouri Research Board (UMRB)
Goal: Bridge approach slabs are reinforced slabs, placed between bridge abutments and approach pavements, to mitigate the effects of changing support conditions. Excessive settlement and cracking of approach slabs due to local compression of compacted embankment soils at the bridge/pavement interface is a major issue. This study aims to develop flowable fill mixtures comprised of quarry fines as an alternative to compacted soils.

Chloride Limits in Fresh Concrete

Principal Investigator(s): Ceki Halmen, Ph.D.
Goal: Chloride induced corrosion of steel reinforcement in concrete is a major problem. Therefore there are strict limits on the chloride content of materials that will be used in concrete mixtures. These limits are typically defined as a percentage of cement weight, however, with the increased use of supplementary cementitious materials the definition of chloride limits based on cement content may be unnecessarily restrictive. This study evaluates validity of chloride limits in fresh concrete and their definition as a weight percentage of cement.

Controlled Low Strength Materials (CLSM) for Bridge Approach Slabs

Principal Investigator(s): Ganesh Thiagarajan, Ph.D., P.E.
Researcher: Ceki Halmen, Ph.D.
Funded by: Missouri Department of Transportation (MoDOT)
Goal: Cracking of bridge approach slabs due to settlement of soils is a major problem. In this study, CLSM is being evaluated as an alternative to compacted granular materials to support bridge approach slabs.