Consolidating concrete vibration
is a concrete mix which has a low yield stress, high deformability, good segregation resistance (prevents separation of particles in the mix), and moderate viscosity (necessary to ensure uniform suspension of solid particles during transportation, placement (without external compaction), and thereafter until the concrete sets).In everyday terms, when poured, SCC is an extremely fluid mix with the following distinctive practical features - it flows very easily within and around the formwork, can flow through obstructions and around corners ("passing ability"), is close to self-levelling (although not actually self-levelling), does not require vibration or tamping after pouring, and follows the shape and surface texture of a mold (or form) very closely once set.Even with true SCC (slump flow greater than 18 inches), contractors will sometimes use a little vibration just to make sure the mix is consolidated, especially with congested reinforcing steel.In a properly proportioned mix, this vibration will not lead to separation of the aggregate from the paste (segregation) although there can be some grout leakage at form joints.If allowed to harden in this condition, the concrete will be nonuniform, weak, porous, and poorly bonded to the reinforcement. On-Demand Course: Concrete Consolidation in the 21st Century On-Demand Course: Concrete Field Testing Technician Grade I Certification Training (with ASTM Standards) On-Demand Course: Concrete Field Testing Technician Grade I Certification Training (without ASTM Standards) On-Demand Course: Contractor's Guide: Chapter 10 Concrete Placement and Finishing View all ACI Online Learning Courses on Consolidation » Question: Factors governing the strength of concrete Question: Factors affecting permeability Question: How is the selection of mixture proportions affected by the materials to be used and the placing...Question: What consideration should be given to water that may be lost from concrete between the time it l...To address the problem of excessive vibration a research project was initiated to document the vibratory practices of PCC slip form paving and determine the effect of vibration on the air content of the pavement.
“If there is access for vibrators then don’t use SCC, but consider “high-flow” concrete,” said Jack Gibbons, technical director for the Concrete Reinforcing Steel Institute, Schaumburg, Ill.
Good concrete consolidation is essential for strong, energy-efficient ICF walls.
Voids and honeycombing can create basement leaks, and in extreme cases, affect the structural integrity of the walls.
As a result, pouring SCC is also much less labor-intensive compared to standard concrete mixes.
Once poured, SCC is usually similar to standard concrete in terms of its setting and curing time (gaining strength), and strength.“Either strike the outside of the wall with a 2x4 or vibrate minimally.” Newer designs are stronger, but still need care.