关于Chengdu wet mix mortarHow about water retention？Little friends are not very confused, the following Xiaobian will tell you。

Although mortar shares some of the main components of concrete, their role is not the same。Usually the concrete is poured in the mold, which can hold most of the water, and the concrete itself can be used as a structural unit;The mortar is usually laid between the absorbent blocks or smeared on the base, and the matrix together to form a whole。As long as the mortar is in contact with the block material or the base, the mortar is sucked out of water, and the external surface of the mortar also evaporates water into the atmosphere, resulting in insufficient water of the mortar due to water loss, which affects the further hydration of the cement, and then affects the normal development of the mortar strength。In addition, the smeared mortar is usually thin in thickness and large in surface area, which is more likely to crack due to dry shrinkage, so it can be seen that the water retention of the mortar has a greater impact on the performance of the mortar。Mortar with good water retention, cement hydration is more adequate, the strength can be normal development, and the base can be better bonded together。

The state limits the use of solid clay bricks, and vigorously promote the use of new wall materials, especially the use of industrial waste production of wall materials, the amount of water absorption of these materials, water absorption speed and sintered clay bricks have a greater difference, the need for mortar with better water retention。Therefore, this standard emphasizes the water retention performance of ready-mixed mortar and determines its indicators through tests。

In China, stratification is traditionally used to characterize the water retention ability of mortar, but this method requires a long test time and a large operating error。Most foreign countries are based on water retention to measure the water retention capacity of mortar, which can more accurately reflect the water retention capacity of mortar。In line with the principle of giving priority to international standards, this standard also uses water retention to evaluate the water retention capacity of mortar and gives the corresponding performance indicators。

The standard preparation group collected lo kinds of ordinary dry mixed mortar samples from the market, and the preparation unit carried out a comparative test of water retention simultaneously. Meanwhile, some tests of cement-lime mixed mortar and thickened powder mortar were also carried out. Some test results are shown in Table 2。A total of 56 test data were obtained in this test, of which the water retention ≥88% accounted for 91%, and the smaller value was 86.4% (at this time, the mortar consistency was 110 mlTl). Therefore, this standard stipulates that the water retention of wet mixed mortar and ordinary dry mixed mortar should be ≥88%。

It can also be seen from the test results that the consistency of mortar has an effect on water retention, and there is an inverse relationship between the two。In order to make the results of each test comparable，The value range of consistency of each mortar in test is specified，That is, the consistency of ordinary dry mixed mortar test is: masonry mortar 70 ~ 80 mm，Plaster mortar 90 ~ 100 mm，Floor mortar 45 ~ 55 mm，Ordinary waterproof mortar 70 ~ 80 mm;Wet mixed mortar is tested according to the actual consistency。

The above about the water retention of wet mixed mortar in Chengdu is explained, and I hope you can see how helpful it is to you!