Title:
Concrete Q&A
Author(s):
Publication:
Concrete International
Volume:
37
Issue:
4
Appears on pages(s):
76
Keywords:
DOI:
Date:
4/1/2015
Abstract:
Q. I understand that ACI 546R recommends limiting chipping hammers to 15 lb to prevent bruising and microcracking of the concrete around a repaired zone. Can you confirm that this limit refers to the weight of the hammer itself and is not a measure of the energy imparted to the concrete (that is, could the value be 15 ft-lb rather than 15 lb)? It seems that different types of hammers (for example, electric, pneumatic, and hydraulic) could impart different amounts of energy to the concrete even if they have identical weights. Is the weight of the hammer the major factor that affects microcracking?