AS 3972-2010 pdf free download

AS 3972-2010 pdf free download.General purpose and blended cements.
A3.3.3 Sirengih
Strength is an important property of cement and, in many cases. determines the value of cement when employed as a structural material. At present. compressive strength is the form of strength required for compliance ssith this Standard for cement. Based on an extensive investigation by the cement industry, a European strength test method was adopted in 1988 as AS 2350.11 (now ASINZS 2350.11). Some modifications to the European Standard were necessary to adapt the method to conditions in AListralia (e.g. a laboratory temperature of 23 ±2°C was adopted). Also, a vibrating table is specified as the standard method of compaction.
A minimum strength is the criterion adopted. The minimum values specified take into account the testing errors, the within-brand and the between-brand strength variation.
A3.3.4 Teniperulure rise/heal of hydration
The rise in temperature in the interior of large concrete sections due to the heat developed during the hydration of cement may lead to cracking. Certain types of cement are produced with a slo rate of heat evolution for use in these applications. Measurement of heat of hdration has been used to characterize these cements. The heat of solution method is specified as the standard method of testing cement by many countries. While it determines with good accuracy the total heat of hydration at later ages (seven days and longer), it gives no indication of the actual temperature rise in concrete under practical conditions. Further. the method is not suitable for blended cements. Based on an earlier investigation it was shown that a method based on a semi-adiabatic calorimeter is capable of measuring the maximum temperature rise of hydrating cement mortar. The heat of hydration can be obtained with good precision up to five days. Also, being semi-adiabatic the method is more relevant to field conditions.
A test method has been developed based on a French test method (Langavant), but modified to put the emphasis on measurement of temperature rise allowing, as an option. the calculation of heat of hydration, if required. This approach was confirmed by the result of a survey of engineerslspecificrs and users. The survey asked participants to nominate %hat was considered a useful parameter for specifying low heat cement: 25% of the respondents nominated heat of hydration and the remaining 75% nominated maximum temperature rise.
A3.3. Drying shrinkage
Where emphasis is placed on shrinkage and crack control in concrete structures, the designer needs to predict shrinkage in the various elements and to accommodate these movements in his or her design. A prerequisite to estimating the shrinkage inovememit in concrete elements (plain, reinforced, or prestressed) is a knowledge of the shrinkage tendencies of the concrete itself. It is generally established that the shrinkage of concrete. AS 3972-2010 pdf free download.