Do we need to use a specialized mixer to mix fiber reinforced concrete?

1. No special equipment is required. Fiber reinforced concrete can be prepared using the commonly used forced concrete mixer on construction sites. To ensure uniform mixing of fibers in concrete, the time can be appropriately extended. One approach is to first mix the concrete as usual, and then without stopping the machine, add the weighed fibers into the concrete and continue mixing for 3 minutes, so that the fibers become single fibers evenly distributed in the concrete mixture. The more commonly used method in practical engineering is to directly mix the fibers with sand and gravel materials in a mixer, which yields better results.

2. Commercial concrete mixed with fibers can be prepared in the concrete mixing plant. The weighed fibers can be manually added directly from the feeding port on the mixing equipment feeding platform. Although the density of the fiber is only 0.91g/m3, practical operation has shown that there will be no flying phenomenon during feeding. The addition of fibers to concrete slightly reduces its slump, but it does not affect the workability of the concrete, nor does it affect the temporal variation of its slump (which mainly depends on the water reducing agent used).