PVA fibers have excellent characteristics for a concrete or mortar repair product. Polypropylene fibers can stretch and allow the concrete to break apart. Glass fibers are fragile and can be easily damaged. Steel fibers can stick out and cause damage and will rust. PVA fibers are superior in several ways:
1. High bond strength with the concrete or mortar will help keep the patch together even if it is damaged;
2. PVA Fibers will not cut the user or equipment;
3. PVA fibers will never rust;
4. High modulus of elasticity and tensile strength help keep the concrete intact;
5. PVA fibers have a very high abrasion resistance;
6. PVA fibers produce concrete and mortar with very high fatigue resistance;
7. PVA fibers are resistant to UV rays and most chemicals.
An amazing feature of PVA is its ability to strain-harden, or get stronger after cracking! Take a road patch for example. Heavy trucks might cause thin areas, or interface areas to crack. Not only do the PVA fibers hang on to the broken pieces, PVA-ECC will require greater and greater force to continue cracking, up to 500 times more in tension than conventional concrete. PVA-ECC is designed for normal operation even after being heavily cracked. In many cases the cracks are so small that they can heal themselves. Microcracks are often under a tenth of a millimeter, too small for water to penetrate.
Seismic repair is another area of strength for PVA fibers. PVA-ECC can be used as a shotcrete overlay to provide seismic remediation to a building, eliminating or reducing extensive steel work to accomplish the same effect. This approach is intended for use on buildings, bridges and piers. We would be pleased to assist you with the engineering required to provide this solution.
PVA fibers can be mixed wet to create your own repair mortar. We have mix designs available for this application. Or PVA fibers can be dry-mixed for creating bagged repair products.
|
|
The University of Michigan and the Michigan Department of Transportation are currently running tests using PVA-ECC for a road repair product. Complete information on the project can be found in this Powerpoint presentation:
ECC information |
Case Study
Undercrossing damaged by salt replaced with PVA-reinforced, self-compacting concrete |
|
