The effect of water retaining agent for ready-mixed mortar on the strength of mortar after hardening is a complex and important issue. The following is a detailed analysis from different angles:
First, water retaining agent improves the construction performance of mortar by absorbing and retaining water, but it may also affect the strength of mortar after hardening. Generally speaking, with the increase of water retaining agent dosage, the water retention performance of mortar will be significantly improved, but the compressive strength may show a gradual downward trend. This is because the organic components in the water retaining agent have a certain air entraining effect. The introduced bubbles are retained in the hardened mortar to form independent pores. Although it can greatly improve the water retention of mortar, it will also reduce the volume density of mortar, resulting in loss of compressive strength.
Secondly, the type and dosage of water retaining agent also have different effects on the strength of mortar after hardening. For example, organic water retaining agents such as hydroxypropyl methylcellulose ether (HPMC), although with low dosage, high water retention rate and viscosity, have a great damage to the later strength of hardened mortar, and the strength loss is usually as high as 10% or more. Inorganic non-mineral water retaining agents such as bentonite and attapulgite, although with large dosage, medium water retention rate and viscosity, will also have an adverse effect on the later strength of hardened mortar.
In addition, the effect of water retaining agent on the strength of mortar after hardening is also related to factors such as the mix ratio and curing conditions of the mortar. Under a certain mix ratio, excessive water retaining agent dosage may cause a significant decrease in mortar strength. At the same time, the quality of curing conditions will also affect the development of mortar strength. Good curing conditions can promote the hydration reaction of cement in mortar, thereby improving the strength of mortar.
The influence of water retaining agent for ready-mixed mortar on the strength of mortar after hardening is multifaceted. In practical applications, it is necessary to reasonably select and control the dosage of water retaining agent according to engineering requirements and material properties to ensure that the mortar has sufficient strength to meet the design requirements.
