Against the backdrop of the increasing depletion of global natural sand resources, the construction industry is facing severe challenges in raw material supply. The emergence of pebble mechanized sand has provided an effective solution to this dilemma and has gradually become an important alternative raw material in the construction industry. Currently, pebble mechanized sand has a very wide range of applications, covering the production of concrete with strength grades C60 and below, basic building construction, transportation engineering construction and other key fields, providing important support for the smooth progress of various construction projects.
From the perspective of advantages, pebble mechanized sand has prominent characteristics in many aspects. Firstly, in terms of raw material supply, the reserves of pebble resources are abundant, ensuring sufficient raw materials for mechanized sand production, and its pure composition reduces the impact of impurities on construction quality. Secondly, in terms of production economy, the production and processing cycle of pebble mechanized sand is relatively short, which can quickly respond to the raw material needs of construction projects. At the same time, the investment cost is relatively low, reducing the production and operation pressure of enterprises. Thirdly, in terms of finished product quality control, the finished product of pebble mechanized sand has a good particle shape, strong quality stability and high controllability. By flexibly adjusting the production process, the fineness modulus can be accurately controlled, and then products of different specifications such as coarse sand, medium sand and fine sand can be produced to meet the diverse raw material needs in construction projects. In addition, in terms of application performance, the particles of mechanized sand are usually arc-shaped. This unique shape enables it to form a stronger bonding degree when used in the bonding of structures such as concrete, ultimately making the concrete have better compressive strength and prolonging the service life of the building structure.
However, pebble mechanized sand also has certain disadvantages in application. Compared with natural sand, natural sand particles are round and smooth on the surface, which is very beneficial to the workability of concrete and makes concrete easier to mix, transport and pour during the construction process. In contrast, the particles of pebble mechanized sand are sharp and angular with rough surfaces, and their fineness modulus is mostly above 3.0, with slightly poor particle gradation. The proportion of particles larger than 2.5mm and smaller than 0.08mm is relatively high. These factors directly lead to poor workability of the concrete prepared with it. During the construction process, problems such as segregation and bleeding are prone to occur, which in turn cause appearance quality defects of concrete, such as surface honeycombs and pockmarks, bringing great difficulties to the quality control work of building construction.
To solve the above problems of pebble mechanized sand, the following improvement methods can be adopted. On the one hand, optimize the gradation and make rational use of stone powder. Enterprises can improve the particle gradation of pebble mechanized sand by selecting appropriate sand-making and screening equipment; scientifically and reasonably use the stone powder contained in the sand (generally, the stone powder content does not exceed 20%) to exert the positive role of stone powder in concrete; at the same time, adjust the sand ratio according to specific construction needs and select suitable admixtures. Through these comprehensive measures, the disadvantage of poor concrete workability can be effectively overcome, and the construction performance and quality of concrete can be improved. On the other hand, promote an environmentally friendly production model. In terms of stone powder content control, appropriate processes can be selected according to product positioning. Dry dust collection technology is used for producing Class III sand, while wet water washing technology can be used for producing high-quality mechanized sand. However, during the wet water washing process, great attention should be paid to water-saving measures and environmental protection requirements to avoid water waste and environmental pollution. In addition, the internal air self-circulation technology of the vortex cavity can be used to reduce energy loss during the production process. At the same time, pulse dust collectors and noise eliminators are equipped to effectively control dust emissions and noise pollution, realizing the goal of green and environmentally friendly sand production and promoting the sustainable development of the construction industry.