The Inevitability of Applying Dry-Mix Mortar
Release Time:
2020-05-11
Source:
Pre-mixed dry-mix mortar is a construction material composed primarily of dry sand, cement, industrial by-products (such as fly ash, steel slag, and desulfurization gypsum), and various additives, all uniformly blended in the factory according to specified proportions. It is supplied to contractors for use in wall masonry, finish work, and floor construction, and is categorized into three main types: masonry mortar, plastering mortar, and floor mortar. With the advancement of construction technology and the ever-increasing demands for construction efficiency and quality, the shortcomings of traditional on-site mortar mixing have gradually become apparent. The primary issues associated with on-site mortar mixing include the following aspects:
1. The mix design is often highly arbitrary, which severely compromises the intrinsic quality of the materials. Given the large number of construction teams and the uneven technical competence among contractors, mix designs are frequently based on experience or borrowed from other projects, with insufficient analysis of the specific characteristics of the selected raw materials and a lack of systematic material-performance testing. As a result, the mortar exhibits poor performance, posing potential risks to the project.
2. Inaccurate on-site measurement and control lead to quality fluctuations. Most construction sites still rely on manual measurement, which results in substantial weighing errors. If the amount of binder is insufficient, strength will decrease; if it is excessive, costs will rise and shrinkage-induced cracking may occur due to the cement’s tendency to contract. Moreover, achieving uniform mixing is difficult. On-site mixing typically uses small mortar mixers, which have limited dispersing capability for low-dose admixtures, often leading to uneven mixing.
4. Low production efficiency. High labor intensity and long working hours lead to increased labor costs per unit of work.
5. The influence of raw materials on mortar performance has increased. Mortars for different applications have varying requirements for aggregates and binders. However, when mortar is produced on-site, constraints related to site conditions and project schedules make it impossible to meet all these requirements individually.
6. Significant environmental pollution. The storage of raw materials and the production process can generate dust, noise, and other pollution sources, thereby contaminating the surrounding environment.
7. Impairment of building functionality and creation of potential safety hazards. Without the guidance of a scientifically validated empirical mathematical model, control of mortar quality can only rely on producing test specimens concurrently and conducting post-curing verification at the prescribed curing age. Even when problems are identified, they are often difficult to rectify. As a result, wall cracking, water infiltration, color variation, and hollowing or spalling of plaster layers frequently occur.
To this end, the factory-based production of mortar has become inevitable. By entrusting material selection and mix design to highly specialized engineers, conducting systematic testing in fully equipped laboratories, employing electronic metering, implementing professional production management, and utilizing dedicated mixing equipment for centralized production, the aforementioned challenges can be effectively addressed.
