An Easy and Right way to control Concrete Workability

1
An Easy and Right way to control Concrete
Workability Philip Chuah
2
How to reach improved performance
BLTs experts have build up an extensive
knowledge on performance of Lignosulfonates based
on

• differences in production processes
• differences in (wooden) raw material
• differences in molecular weight
• Adsorption studies
• fractionation
• chemical modification

3
How to reach improved performance
BLT developed the first Lignosulfonate based
premium grade by

• evaluating the differences in pulping process
  and identify the best
• identifying the most suitable wooden raw
  materials
• identifying the most effective LS ingredients by
  Adsorption studies
• identifying the optimum LS molecule size by
• selective fractionation
• adsorption studies and performance
• evaluating performance improvement by
• chemical modification
• grafting

4
Performance in concrete
Concrete mix design
Cement CEM I 42,5 R in accordance with EN
197-1 Cement content 355 kg/m³ w/c ratio
0.42 matrix volume 288 l/m³ Filler content
40.9 of cement defoamer (TBP) 0,5 on dry
matter (DM)
matrix cement filler water admixture
5
Performance in concrete
Workability / slump at different dosages
increased performance To reach a given level of
workability the dosage is significantly lower
than for synthetics
sbwc solid by weight of cement
6
Performance in concrete
Set retardation at different dosages
sbwc solid by weight of cement
7
Performance in concrete at same slump
reduced set retardation To reach a given level
of workability the retardation is significantly
lower than for Ultrazine
8
Performance in concrete
Air content at different dosages
0.5 defoamer TBP has been added on DM.
sbwc solid by weight of cement
9
Performance in concrete
28 days compressive strength at different dosages
0.5 defoamer TBP has been added on DM.
sbwc solid by weight of cement
10
Rheological properties
Jon Elvar Wallevik has shown in his phD-thesis
that there is a strong and simple relationship
between concrete workability and the yield value
of the referring concrete, mortar and cement
paste
workability
low
high
yield value
high
low
11
Rheological properties
concrete mix design
Cement CEM I 42,5 R in accordance with EN
197-1 Cement content 442 kg/m³ w/c ratio
0.40 matrix volume 320 l/m³
- aggregates 2 - 8 mm
mortar mix design
Cement CEM I 42,5 R in accordance with EN
197-1 Cement content 770 kg/m³ w/c ratio
0.40 matrix volume 558 l/m³
12
Yield value at different temperatures - LS
Standard grades vs. Ultrazine grade
13
Yield value at different temperatures - NFS
standard grade vs. Ultrazine grade
14
Yield value at high temperature - Ultrazine grade
vs. Solus 5 vs NSF standard grade
15
Using in admixture formulations

• Solus 5 can be used alone and or with other raw
  materials, to formulate as
• high-range water reducer
• retarding high-range water reducer
• mid-range water reducer
• Maximum solids content of admixture liquid
  
• should not exceed 30(w/w) at 30oC ambient
• (due to viscosity See Appendix A)
• Solus 5 is compatible with most common raw
  materials
• naphthalene sulfonate, melamine sulfonate,
  polyacrylates, PCEs
• gluconates, phosphates, sugars, etc.

16
Using in admixture formulations

• The use a suitable defoamer like TBP at 0.2 to
  0.5 is necessary to control foaming to suitable
  level in admixture and concrete. Usually,
  adding TBP at 0.2 suffice.

17
Evaluation of

• Solus 5 is not designed for plasticizer
  applications
• Solus 5 should therefore be evaluated as a
  Retarding High Range Water Reducer

Recommended concrete mix design Cement content
gt 350 kg/m³ w/c ratio lt 0.50 to 0.40 Guide
dosage gt 0.50 sbwc or higher for same
workability for all samples same dosage and w/c
ratio
Note As a performance reference, the inclusion
of a naphthalene sulfonate in the test procedure
is highly recommended.
sbwc solid by weight of cement
18
Appendix A Viscosity of solutions
19

• Notes
• Maximum solid in solution for easy handling is
  28 to 33 at temperature from 10oC to 30oC
• The maximum solid for easy handling is defined as
  solution viscosity lt 200cps . This viscosity is
  dependant on the capability of the pump at the
  admixture production plant and pump at the ready
  mix admixture dosing gauge

20
How to use in admixtures

• Max. DM content
• should not exceed 30 due to viscosity reasons
• Solus 5 can be used alone or in combination with
  other RM to develop
• superplasticizer/High range water reducer
• retarding superplasticizer/High range water
  reducer
• mid range water reducer
• Solus 5 is compatible with most common raw
  materials, e. g.
• naphthalene sulfonate, melamine sulfonate, poly
  acrylates, PCEs
• gluconates, phosphates sugars, etc.
• lignosulfonate - are not recommended due to
  loss in performance

21
How to judge test results
low initial slump
low slump retention
bleeding / segregation
high air content
22
How to judge test results
low initial strength
low final strength