The U.S. Department of Transportation Federal Highway Administration (FHWA) has released a Tech Brief titled “Materials-Related Distress: Hardened Cement Paste – Best Practices for Concrete Pavements”. Concrete is a cemented-aggregate mixture where aggregates are bound together by a cementitious matrix, or hardened cement paste (HCP). Both the aggregates and HCP need to be considered when discussing concrete durability or materials-related distress (MRD).
The purpose of this tech brief is to provide pavement engineers with information to help them specify and choose materials that will last for the desired lifetime of the pavement. This tech brief focuses on considerations for the cementitious matrix with respect to paste-related distress mechanisms. Aggregate-related mechanisms are discussed in a separate parallel tech brief (Taylor and Wang 2015).
HARDENED CEMENT PASTE There currently is no definition for HCP within ASTM Committee C09 on Concrete and Concrete Aggregates or the American Concrete Institute (ACI). For the purposes of this tech brief, HCP is considered to include cement, supplementary cementitious materials (SCMs), water, hydration products, any admixtures, and entrained air.
MATERIALS-RELATED DISTRESS (MRD) refers to “concrete failures that are a direct result of the properties of the material and its interaction with the environment to which it is exposed” (Van Dam et al. 2002a). Failures due to MRD are not related to either inadequate design for the loading conditions encountered or improper construction practices.
The tech brief continues with:
FREEZE-THAW DETERIORATION
What is it?
Identification
Prevention
DEICER SCALING
What is it?
Identification
Prevention
SULFATE ATTACK (EXTERNAL AND INTERNAL)
What is it?
Identification
Prevention
CORROSION OF EMBEDDED STEEL
What is it?
Identification
Prevention
REPAIR
The Tech Brief, “Materials-Related Distress: Hardened Cement Paste – Best Practices for Concrete Pavements”, by authors Peter Taylor, Director National Concrete Pavement Technology Center and Lawrence L. Sutter, Professor Materials Science and Engineering Michigan Technological University, was developed under Federal Highway Administration (FHWA) contract DTFH16-14-D-0005.
To download the entire report in PDF form, please click here.
