Humboldt HC-2940 concrete crack width gauge is designed to measure the widths and locations of cracks prior to the start of a monitoring program. This concrete crack ruler can be used both internally and externally.
Features:
- It is made of polycarbonate, which has a coefficient of linear thermal expansion of 7 x 10-5 cm/cm/degrees Celcius for ambient temperatures ranging between -30 and 30 degrees Celcius.
- To facilitate measuring cracks in corners, the scale is calibrated from the gauge's end.
- It comes in a protective case.
Standards and Approvals:
- BS EN ISO 9001:2000
- ACI 2242-01
Frequently Asked Questions:
Q. What is the upper width limit for hairline cracks?
A. Cracks having width less than 0.3 mm are acceptable and have no effect on the structure. Cracks having width more than 0.3 mm can jeopardise the structure's durability.
Q. How do you measure concrete crack widths?
A. The maximum crack spacing is multiplied by the mean strain of the flexural steel reinforcement, yielding the crack width of a flexural member.