Civil Engineering Reference
In-Depth Information
Strength and density
Cores taken from the placed material can be tested as for normal concrete.
Although the core diameter is usually small, the aggregate is also smaller
than for conventional concrete and specimen size and proportion allowances
can be made.
In situ testing
There are various tests which can be carried out
in situ
.
Entrapments of sand or rebound material, if suspected, can be verified by
taking cores. Ultrasonic pulse velocity testing (Pundit) can be used to indicate
strength and thermography or x-rays can be used, if rarely, to evaluate the
condition of the sprayed concrete.
Daily test panels
Whilst these are normally specified, to test mainly for compressive strength
and density, they may not represent the concrete in the works. The nozzleman
obviously knows what test panels are and what they are used for, so he
ensures that only the best concrete and workmanship go into them. The
quality of concrete at start-up is frequently below the required standard.
