Our concrete structure is newly formed. Why people say that it is cracked concrete?
Hi Keith,
Thank you for the question.
Cracked concrete is not related to the age of the structure, rather it is related to the loading condition of the concrete structure. According to HK CoP SUC 2013 Clause 7.2.1 "Cracking is normal in reinforced concrete structures subjected to bending, shear, torsion or tension resulting from either direct loading or restraint of imposed deformation".
Concrete is a brittle material and can only withstand small amount of tensile strain due to stress before cracking. If the tensile strength of concrete is exceeded, cracks form, which, as a rule, cannot be seen. Experience has shown that the crack width does not exceed the figure regarded as admissible, i.e.. approximate w=0.3mm, if the concrete is under a constant load.
It is recommended that anchors that are approved for use in cracked concrete such as Hilti HDA, HSL3, HST3 and HY200 be used in the tension zone of concrete components.
Please let us know if you have any further questions.
Cheers,
Tania