Norm

ASTM C688 - 08 en

Standard Specification for Functional Additions for Use in Hydraulic Cements

  • Deze norm is ingetrokken sinds 01-12-2008

50,60 61,23 Incl BTW

Over deze norm

Status Ingetrokken
Aantal pagina's 5
Gepubliceerd op 01-12-2008
Taal Engels

1.1 This specification covers methods to investigate the effectiveness of a material to beneficially change the properties of hydraulic cements when the material is incorporated during manufacture of the cement.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 The effect of additions in cement may markedly change properties other than those they are intended to modify. This specification is designed to test for such changes. Table 1 sets forth values for those properties of cement pastes and mortars that would permit a judgment of the changes effected by an addition. Likewise, Table 2 sets forth similar criteria for concrete. Certain additions may be found effective for more than one purpose as indicated in 3.1.4 and 3.1.5.

TABLE 1 Criteria for Evaluating Neat Cement and Mortar Containing Functional Cement Additions

TestsType of Addition
Water Reducing RetardingAcceleratingWater-Reducing
and Retarding
Water-Reducing and
Accelerating
Set-Control
Normal consistency, deviation from control,
percentage pointsA
1.0 min+1.0 max+1.0 max 1.0 min 1.0 mm±1.0 max
Standard consistency (flow) deviation from
control, percentage pointsA
4.0 min+2.0 max+2.0 max 4.0 min 4.0 min±2.0 max
Setting time, (Gillmore) deviation from control,
h:min
Initial
At least ...1:00 laterB 1:00 laterB ...
Not more than 1:00 earlier3:30 later1:30 earlier 3:30 later 1:30 earlier1:00 earlier
nor nor nor nor
1:30 later1:30 later 1:30 later1:30 later
Setting time, Vicat InitialC
At least ...0:50 laterB... ......
Not more than 0:50 earlier2:50 later1:15 earlier 0:50 laterB 1:15 earlier0:50 earlier
nor nor nor nor
1:15 later1:15 later 2:50 later 1:15 later1:15 later
Final
Not more than 1:00 earlier3:30 later1:00 earlier 3:30 later 1:00 earlier1:00 earlier
nor nor nor nor
1:30 later1:30 later 1:30 later1:30 later
Compressive strength, min, percent of control:D
1 day in moist air 11090125E 90 125F
1 day in moist air, 2 days in water 11090125E 100 125
1 day in moist air, 6 days in water 11090100 110 110
1 day in moist air, 27 days in water 1109595 110 110
Autoclave Expansion
max increase in % change in length compared to control

0.10

0.10

0.10

0.10

0.10

0.10
Drying Shrinkage of Mortar
max % change in length compared to control

0.020

0.020

0.030

0.020

0.020

0.020

A The minus sign indicates that the percentage of water required shall be less than that of the control cement by at least the indicated percentage points.

B Or 50 % later, whichever is the lesser.

C Either Vicat or the Gillmore time of setting method shall be used at the choice of the manufacturer.

D The compressive strength of mortar containing the test cement shall be not less than 95 % of that attained at any previous test age. The objective of this limit is to require that the strength of mortar containing the addition under test shall not decrease with age.

E In cases where the accelerated set time only is required, the strength can be reduced to 100 % of the control.

F The grand average of the 1, 3, 7, and 28-day strengths shall be not less than 95 % of the grand average for the corresponding control cement.

TABLE 2 Criteria for Evaluating Concrete Containing Functional Cement AdditionsA

TestsType of Addition
Water Reducing RetardingAcceleratingWater-Reducing
and Retarding
Water-Reducing
and Accelerating
Water content, max, percent of control 95...... 95 95
Time of setting, (penetration) deviation from
control, h:min:
Initial
At least ...1:00 laterB 1:00 laterB
Not more than 1:00 earlier3:30 later3:30 earlier 3:30 later 3:30 earlier
nor
Final 1:00 later
Not more than 1:00 earlier3:30 later... 3:30 later ...
nor
1:30 later
Compressive strength, min, percent of
control:C
1 dayD 11085125E 100 125
3 days 11085125E 100 125
7 days 11090100 110 110
28 days 1109095 110 110
3 months 1009095 100 100
1 year 1009095 100 100
Flexural strength, min, percent of
control:C
1 dayD 10085110 90 110
3 days 10085110 100 110
7 days 10090100 100 100
28 days 1009090 100 100
3 months 1009090 100 100
1 year 1009090 100 100
Bond strength, percent of control:
28 days 10090100 100 100
Volume change, expressed as change in
length, max, increase over control,
percentage points:
28 days 0.0100.0100.030 0.010 0.010
3 months 0.0100.0100.030 0.010 0.010
1 year 0.0100.0100.030 0.010 0.010
Durability factor, min, percent of controlF 808080 80 80

A The values in the table are intended to allow for normal variation in test results. For example, the object of the 90 % compressive strength requirement for a retarding addition is to require a level of performance comparable to that of the reference concrete.

B Or 50 % later, whichever is the lesser.

C The compressive and flexural strength of the concrete containing the addition under test at any test age shall be not less than 90 % of that attained at any previous test age. The objective of this limit is to require that the compressive or flexural strength of the concrete containing the addition under test shall not decrease with age.

D One-day strengths applicable only to Type III cement. One-year strength tests shall be made; however, the addition may be approved after completion of the 3-month strength results, at the discretion of the purchaser.

E In cases where the accelerated set time only is required, the strength can be reduced to 100 % of the control.

F This requirement is applicable only when the addition is to be used in air-entrained concrete.

Details

ICS-code 91.100.10
Engelse titel Standard Specification for Functional Additions for Use in Hydraulic Cements
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