- Apr 18, 2018 -
First, the workability of fresh mortar
The workability of mortar refers to whether mortar is easy to lay on the surface of masonry and other uniform, continuous thin layer, and is closely bonded with the base layer. Including the meaning of mobility and water retention.
The factors influencing the fluidity of mortar are mainly the type and amount of cementitious materials, the amount of water used and the type of fine aggregate, the shape of the particles, the degree of thickness and the gradation, in addition to the mixed materials and admixtures that are also incorporated. The variety and dosage are related.
Under normal circumstances, the substrate is a porous, water-absorbing material, or a mortar with a high fluidity should be selected when it is applied under dry heat conditions. On the other hand, if the substrate has low water absorption, or if it is to be constructed under wet and cold conditions, mortar with low fluidity should be selected.
(two) water retention
Water retention refers to the ability of the mortar to retain moisture. Poorly water-retaining mortar has bleeding and streaming during use, which makes the mortar and the substrate sticky. The loss of water affects the normal cohesive hardening of the mortar, which reduces the strength of the mortar.
The main factors affecting the water retention of mortars are the type and amount of cementitious materials, sand type, fineness, and water consumption. In the mortar mixed with lime paste, fly ash and other powdery mixed materials, can improve the water retention of the mortar.
The water-soluble high-viscosity polyacrylamide can not only significantly improve the construction workability of cement mortar, but also does not impair the mechanical properties; the ready-mixed mortar has a long setting time and adjustable, good water retention, and less bleeding during the passage of time. The advantages;