slump test without additives
slump test without additives
(OP)
Hi guys,
i had an inspection on a site where they were pouring a concrete Slab. The concrete is C35/45. The concrete slump is reaching 21 cm although no superplasticizer has been added to the mix. it is too much since the allowable for slabs as i know is around 14 cm.
What is weird is that the cube tests are giving very good results. The recommnended is 45 and they are reaching 55Mpa.
any ideas ?
i had an inspection on a site where they were pouring a concrete Slab. The concrete is C35/45. The concrete slump is reaching 21 cm although no superplasticizer has been added to the mix. it is too much since the allowable for slabs as i know is around 14 cm.
What is weird is that the cube tests are giving very good results. The recommnended is 45 and they are reaching 55Mpa.
any ideas ?





RE: slump test without additives
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RE: slump test without additives
Such high slump is not possible without plasticizer.. anyways its hand mix or RMC.. nowadays nearly all mix are design with additives
RE: slump test without additives
Slump is an indicator of variation between batches, no more, no less. Also, why would slump be tested at a different time from taking strength samples unless slump is done first, then strength samples taken AFTER admixtures have been added?
Without details, I would predict excessive shrinkage of the slabs. High slump (without water reducer) with high strength usually indicates a high cement content which usually leads to greater shrinkage. Shrinkage in slabs usually means curling, and curling means cracking.
RE: slump test without additives
High slump concrete can be produced with high strength....it is the water-cement ratio that determines strength.
RE: slump test without additives
master ICC inspector, AWS CWI