GB / T 13477.17-2017 determination of elastic recovery rate was implemented on February 1, 2018, which is applicable to the determination of elastic recovery rate of building sealing materials.
　　
Compared with GB / T 13477.17-2017 and GB / T 13477.17-2002, the main technical changes are as follows:
——Revised scope (see Chapter 1):
In this part, the "elastic recovery rate after continuous stretching" in 2002 edition is modified to "elastic recovery rate after being maintained in stretching state", so as to make the expression more accurate, and it is consistent with the expression of ISO 7389:2002 "determination of elastic recovery rate of sealing materials for joint products of building structures".
　　
——Revised normative references (see Chapter 2):
Added reference document GB / T 22083-2008 classification and requirements of building sealant (iso116000:2002, MOD)
　　
——Revised the principle statement (see Chapter 4):
This part of the statement of test piece production in 2002 edition of the principle is deleted, so as to be consistent with the expression of ISO 7389:2002 "determination of elastic recovery rate of sealing materials for joint products of building structures".
　　
——The test apparatus is modified (see 6.1, 6.3, 6.6, 6.7, figure 1 and Figure 2 in Chapter 6):
(1) In this part, the characteristics of bonding base material, positioning pad, tensile testing machine and container in 2002 edition of test apparatus are modified to be consistent with the expression of ISO 7389:2002 "determination of elastic recovery rate of sealing materials for joint products of building structures".
　　
(2) A measuring tool is added to measure the failure depth of the specimen after stretching, so as to determine whether the specimen is damaged or not.
　　
——The number of specimens prepared was modified (see Chapter 7):
The number of test pieces prepared is increased from 3 to 6, so that when the test pieces are found to be damaged, there are spare test pieces for repeated test.
　　
——The test procedure was modified, the content of specimen failure was added, and table 1 was deleted (see Chapter 9):
During the operation of 2002 edition of this part, the editor in chief often receives the user's reflection in the elastic recovery rate test. If the test piece is damaged, he does not know how to deal with the test data and report the test results, which is not specified in this part and the text of ISO 7389. Therefore, the 2017 new edition of this part, after soliciting the suggestions of experts and inspectors, decided to add the corresponding treatment method in this article, that is, "observe whether the test piece is damaged according to 7.3 of GB / T 22083-2008 in the test process.". If there is no damage, remove the positioning block If the test piece is damaged, take the spare test piece and repeat this part of the test. If there is still damage in 3 repeated test pieces, the test result in this part of the report is the damage of the test piece. "
　　
——The contents of the test report (see item a, C, e, H) and I in Chapter 11) are modified:
(1) "Laboratory name and test date" and "chemical category and color of samples" are added to conform to the expression of ISO 7389:2002 "determination of elastic recovery rate of sealing materials for joint products of building structures".
(2) The report content of "test piece failure" is added to be consistent with the provisions of this part of test steps.
Elastic recovery sample and special cushion block
　　
There are two principles in the revision of this standard: actively adopting international standards, further improving the standard collection rate and combining with national conditions to ensure the coordination between standards. GB / T 13477.17-2017 "determination of elastic recovery rate" well implements these two principles. Through several modifications, it is consistent with the expression of international standard ISO 7389:2002, determination of elastic recovery rate of sealing materials for joint products of building structures; The national standard GB / T 22083-2008 classification and requirements of building sealants has been used for many years, which is familiar to the users of standards in the industry. The reference document of GB / T 13477.17-2017 determination of elastic recovery rate is added this time, and GB / T is adopted 7.3 in 22083-2008 "classification and requirements of building sealants" is used to judge whether the test pieces are damaged, which not only solves the problem of the original standard without the post-treatment scheme of test piece damage, but also ensures the coordination between the standards.
By online
Source: Guangzhou Baiyun Chemical Industry Co., Ltd
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