Реферат

This specification covers methods to investigate the effectiveness of a material to beneficially change the properties of hydraulic cements when the material is interground with the clinker during manufacture of the cement. Cement, mortar, and concrete shall be tested and the individual grades shall conform to specified values of autoclave expansion, drying shrinkage, normal consistency, standard consistency, setting time, compressive strength, false set, water content, flexural strength, bond to steel, volume change, resistance to freezing and thawing, and bleeding. Accelerating addition, retarding addition, set-control addition, water-reducing addition, water-reducing and accelerating addition are detailed.

Область применения

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 RetardingWater-Reducing and
AcceleratingSet-Control Normal consistency, deviation from control,
percentage points^A −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 points^A −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 later^B 1:00 later^B ... 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 Initial^C At least ...0:50 later^B... ...... Not more than 0:50 earlier2:50 later1:15 earlier 0:50 later^B 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 11090125^E 90 125^F 1 day in moist air, 2 days in water 11090125^E 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 Additions^A

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 later^B 1:00 later^B 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 day^D 11085125^E 100 125 3 days 11085125^E 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 day^D 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 control^F 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.