The 28th day is the standard curing period of mortar from the day when you apply for inspection and build the wall, but in special circumstances, it is ok as long as it does not exceed 30 days.
Is it a grade of mortar every 250m when it is submitted for inspection? Send a group, a group of 3 yuan. Write your number clearly on the test block, as well as the place and production date (that is, the day you applied for inspection).
Extended data:
To evaluate the strength grade of mortar test block, the standard curing test block for 28d shall prevail. The test block is a cube with a side length of 70.7 mm, and the three test blocks are 1 group. The number of groups shall meet the following requirements:
1, mortar test blocks with different strength grades and different mixing ratios should be made separately, and the test blocks should be taken with the organization and cannot be selected.
2, important and main masonry, each shift system for 2 groups. General and secondary masonry, each class can do 1 group.
3, arch ring mortar test block should be made with masonry curing test block at the same time, in order to check the strength of each construction stage.
Test block production requirements
1, on the surface of mortar test block, production date, strength grade, location and mortar type must be written.
2. Mortar test blocks shall be "standard maintained" under standard maintenance conditions. When there is no "standard condition" in the construction site, natural curing can be adopted, or the test block can be sent to the laboratory for "standard curing" as soon as possible (the test block must not vibrate) to ensure the accuracy of the compressive test value of the test block.
3. The production and inspection of test blocks must be attended and witnessed by certified witnesses. When the test block is sent to the laboratory, the entrustment form should be filled in carefully. Indicate the use location, mortar type, strength grade, project name, production date, mixture ratio, consistency and curing conditions. After the report is released, it is not allowed to change the relevant contents.
According to the Technical Specification for Production and Application of Ready-mixed Mortar (DC/TJ08—502—2000), the samples of ready-mixed mortar test blocks are as follows:
1. After the mortar is delivered to the delivery place, the sample inspection shall be completed within 20min according to the Basic Performance Test Method of Building Mortar (JGJ 70- 1990), and the consistency test and strength test block making shall be completed within 30min.
2. Samples shall be randomly taken from transport vehicles, and the unloading amount during unloading is about 1/4 to 3/4.
3. The sample size should be 1.5 times of the amount required for mortar quality inspection items, and should not be less than 0.0 1M3.
4, mortar strength inspection sampling, masonry mortar sampling frequency according to the masonry mortar 2, ground mortar according to the building ground engineering cement mortar 1.
5, mortar consistency samples should be each car sampling inspection.
References:
Baidu encyclopedia-mortar test block