We found out some cracks and maybe even fractures in a concrete slab of a reinforced soil wall, i Think they aré caused by a poor construction joint and thermal stress.
what do you think, can i determine the length and widith of the crack with UT?
Hello Dear David
for cracks you asked in your project many reasons interference.
some reasons are in all conditions and some of them are specific for exact projects.
in your figure i saw the length of you concrete span is more in comparison of thickness and I think it lies in soil and not have supports to prevent of cracks creation.
another reason is thermal as you said and I wont to give more information.
another reason is poor construction materials.
another reason is Hydration of concrete and evaporate the water of concrete.
next reason is the loading of your concrete slab.
another reason is settlement of soil and therefore the load apply to your concrete slab not contributed normally in all area with same pressure.
the loading condition is important.
concrete production is important.
human mistakes...
wrong analysis...
ect...
these are the concrete cracks reasons.
and you can modeled your structure in some software and find the cracks will appear (approximately...)
and you can do some works to prevent from more cracks appear in future .
hi David
in my opinion many items interfere to cause the crack such as creep, thermal stresses, span length, etc.
It is much better to give more details to figure the reason out. Even the concrete slab age can play the important role as we know.
Thermal stress can be one of those items.
Best Regards
Hi David,
Cracks in concrete are not only due to thermal changes but also due to shrinkage (viz. moisture changes). Generally, as a thump rule, the slab length and width shall not be more than 2 m to avoid cracks without reinforcement. Or else, temperature reinforcement will be required to avoid cracks if the concrete slab panels to be poured are more the 2 m X 2 min size.
Differential settlement could also be a cause. This crack is horizontal. May be the foundation under this particular wall has sunk down
Differential settlement, is the slab has an elevation change from one side of crack to another.
thermal if crack has no elevation change
Spacing of control joint too far.
No construction joints.
Poor curing procedures
Hello Dear David
for cracks you asked in your project many reasons interference.
some reasons are in all conditions and some of them are specific for exact projects.
in your figure i saw the length of you concrete span is more in comparison of thickness and I think it lies in soil and not have supports to prevent of cracks creation.
another reason is thermal as you said and I wont to give more information.
another reason is poor construction materials.
another reason is Hydration of concrete and evaporate the water of concrete.
next reason is the loading of your concrete slab.
another reason is settlement of soil and therefore the load apply to your concrete slab not contributed normally in all area with same pressure.
the loading condition is important.
concrete production is important.
human mistakes...
wrong analysis...
ect...
these are the concrete cracks reasons.
and you can modeled your structure in some software and find the cracks will appear (approximately...)
and you can do some works to prevent from more cracks appear in future .
Analysis of the possible movements for the formation of each crack is vital in order to understand the cause of the cracking and in order to take the correct action for repair or counter-action (e.g. if the crack is a (very seldom) sign of structural failure).
However, very often, - as also mentioned in the thread above - cracks forming without external loads or external displacements occur. How to design reinforcement in order to control such cracking due to shrinkage, creep and temperature variations has been dealt with for approx. 17 years in the Danish Codes of practice for design of concrete structures, cf. the attached paper. The design rule has proven efficient and correct and it is also given in EN 1992-1-1 DK NA2013 Sect. 7.3.2(1)P.
Dear all,
Its very interesting topic. We shall carry on discussion and brain storming on such topics to disseminate knowledge.
Hi Sir,
Its very interesting topic. The following article links may help you,
https://www.researchgate.net/project/Mode-I-Fracture-Parameters-Using-Steel-Fibers-in-High-Strength-Concrete.
https://www.researchgate.net/publication/301348952_Licensed_Under_Creative_Commons_Attribution_CC_BY_Investigation_on_Mode_-_I_Fracture_Parameters_Using_Steel_Fibers_in_High_Strength_Concrete
Article Licensed Under Creative Commons Attribution CC BY Investigat...
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