Definition

The wet-mixed mixture made by adding water and mixing is called wet-mixed mortar. Wet-mixed mortar is all common mortar, including four types: wet-mixed masonry mortar, wet-mixed plastering mortar, wet-mixed floor mortar and warm-mixed waterproof mortar.

Advantages

There is no need for secondary mixing at the construction site. It can be directly used upon transportation to the site.

2. Factory centralized production and mixing ensure relatively stable quality.

3. Compared with dry-mixed mortar, its cost is slightly lower

Disadvantage

The quality is affected by transportation factors and setting time. A setting time that is too long will affect subsequent construction, while a setting time that is too short may lead to the scrapping of mortar.

2. It is not suitable for small-scale use.

The mortar transported to the site must be used within the prescribed time.

Wet-mixed mortar is suitable for large-scale simultaneous construction of the same material. Its advantage is low investment, and it can be produced with the existing equipment of the concrete mixing plant

The main disadvantages of wet-mixed mortar

1. Production stage: Mortar requires scheduling. If a concrete mixing plant is used to produce wet-mixed mortar, it is difficult to guarantee the selection of raw materials, the batching accuracy of the gradation equipment, the sensitivity of valves, and the use of trace admixtures. Even professional wet-mixed mortar stations are not suitable for producing mortar with high viscosity. As a result, the variety of wet-mixed mortar is limited, and they are unable to supply special mortar. Their profits and the space for further expansion are also limited. At the same time, the annual output of a single line cannot meet the government's filing standards, and the investment risk is high with little return. Dry-mixed mortar factories can produce various types of mortar to meet customer demands and are not restricted by equipment. Although the drying of wet sand incurs a cost of 10 to 12 yuan per ton, the cost of drying can be offset in the logistics process alone. At the same time, most ordinary mortars are made from machine-made sand recycled from solid waste, without drying, and can enjoy tax reduction and exemption policies.

2. Logistics link: Each ton of wet-mixed mortar contains 170 to 190 kilograms of water, which is 15% more than the transportation volume of dry-mixed mortar. The electricity consumption required for production and the fuel consumption required for transportation in this part are both additional costs. Its supply mode is small quantities and multiple times, which greatly increases the number of transport vehicles. Moreover, the increase in frequency is also restricted by traffic control. When large vehicles deliver small materials, the supplier may even suffer losses. Wet-mixed mortar requires the construction of mortar pools and cannot be stored in a sealed manner. It provides the possibility of adding counterfeit and shoddy materials. Meanwhile, the mortar construction is widely distributed and there are many variable factors at the construction site. If the mortar is not used up by the due date, it will be wasted according to the regulations. If it is reused in the project after adding water or cement, it will also pose potential accident hazards.

3. Construction stage: The organization of wet-mixed mortar construction is difficult, and the quality of the project is hard to control. Take masonry mortar as an example. About 0.064 cubic meters of mortar are used for each square meter of masonry. In actual construction, the amount used is even less. One truckload of 8 cubic meters of mortar can build 125 cubic meters of masonry. Taking a 200-millimeter-thick wall as an example, the equivalent wall area is 625 square meters. Therefore, a large amount of manpower (about 70 people) and material resources need to be concentrated simultaneously for construction. It has increased the difficulty of organizational management and security risks. Before the operation of wet-mixed mortar, it is basically necessary to add water for secondary mixing to achieve full hydration, which increases the difficulty of quality control. At present, the open time of wet-mixed mortar is mostly designed to be 24 hours. According to the "Standard Test Methods for Basic Properties of Building Mortar" (1GJ70-2009), when determining the setting time of wet-mixed mortar, the time interval can be determined based on the actual situation. If it can be determined at 1/4, 1/2, 3/4, etc. of the predicted setting time of the inspected mortar, when approaching the setting time, it should be changed to be measured every 15 minutes. In fact, the personnel and technical conditions configured according to this standard are not in place, which brings hidden dangers to the final construction quality. The dry powder sand is mixed and used immediately, so this problem does not exist.