Viability of Fiberglass Mesh Joint Reinforcement or Polypropylene Fibers in Mortar for Crack Control

Grantee: CMHA Research and Development Laboratory
Principle Investigators: Tim Jones
Year: 2020
Project Number: 2020.027
Status: In Progress

The combination of veneer ties and bed joint reinforcement can result in congestion issues for concrete masonry veneers. This project investigates alternatives to mitigate cracking in concrete masonry veneers.

Program Details:

Cracking occurs in concrete masonry assemblies as a result of a number of factors such as the expansion and contraction within the masonry materials due to temperature and moisture changes, the movement of adjacent materials such as beams or slabs, and carbonation. To mitigate shrinkage related cracking, a combination of horizontal reinforcement and vertical control joints are used to relieve tensile stresses within the assembly and mitigate cracking potential. For concrete masonry veneers, the combination of joint reinforcement and veneer ties placed in the same bed joint can result in congestion issues where there simply isn’t enough space to accommodate the placement of both embedded items and maintain adequate cover distances for strength and corrosion resistance.

To alleviate this congestion issue, the CMHA Research and Development Laboratory is going to evaluate the effectiveness of replacing joint reinforcement with fiberglass mesh or addition of polypropylene fibers to the mortar.

This grant will be a pilot project to study the shrinkage cracks on a concrete masonry brick panel having fiberglass mesh joint reinforcement or polypropylene fibers in mortar. Different scenarios such as saturation conditions of units, spacing of fiberglass mesh reinforcement, and volume fraction percentage of fiber in mortar will be evaluated.