The Role of Fibrillated Fibers in Shrinkage Crack Control

pioneerfiber
Jul 8
2 min read

Introduction: Cracks Don’t Wait for Loads

Not all cracks are caused by structural stress. In fact, many appear within the first few hours after placement—before any load is applied. These are plastic shrinkage cracks, driven by rapid moisture loss, temperature changes, and early-stage volume reduction.

PIONEER®’s fibrillated polypropylene fibers offer a proactive solution for shrinkage crack control, forming a multidirectional internal mesh that prevents cracks from developing in the first place.

Why Shrinkage Cracks Happen

Shrinkage cracks typically occur due to:

Plastic shrinkage: water evaporates faster than bleeding can compensate

Drying shrinkage: long-term volume loss as water escapes hardened concrete

Thermal shrinkage: temperature gradients during curing

Autogenous shrinkage: internal chemical hydration processes

These mechanisms reduce concrete volume unevenly, leading to internal tensile stress. Without reinforcement, the surface can crack within hours of pouring.

How Fibrillated Fibers Prevent Cracking

Unlike steel mesh or bar, which only activates after cracks appear, fibrillated polypropylene fibers intercept stress before cracks can form. Here’s how:

Three-dimensional distribution: Fibers spread evenly in all directions during mixing
Crack bridging: Fibers restrain microcracks from growing into visible surface cracks
Tensile stress dispersion: Fibers absorb early shrinkage stress across the matrix
Improved cohesion: Reduces segregation and settlement cracking

PIONEER®’s fibrillated structure ensures strong mechanical interlock within the cement paste, maximizing resistance to both plastic and drying shrinkage.