SY-K expansion fiber anti-crack waterproof agent is composed of sulphoaluminate micro-expansion agent, polypropylene fiber, waterproof agent, reinforcing agent and other functional materials. This product not only has the advantages of crack-resistant fiber, but also has the super-superposition effect of high crack resistance and high permeability. It is a composite material with perfect mechanism and excellent performance. There are many manufacturers of this product in the market, which are uneven (1). Technical features (1) Double protection and double function: SY-K expansion fiber anti-crack waterproof agent can improve the anti-crack ability of concrete from both physical and chemical aspects, and provide double protection for concrete. On the one hand, a large number of synthetic fibers have the function of fine ribs and mesh support, which inhibits the cracking process of concrete; On the other hand, the swelling component reacts with the hydration products of cement and expands moderately, which can prevent the shrinkage and cracking of concrete; (2) Stage crack resistance and spalling resistance: Micro-expansive agent mainly plays a role in the hardening process of concrete, and polypropylene fiber mainly plays a role in the plastic stage of concrete. SY-K expansive fiber anti-crack waterproof agent combines the two, which embodies the scientific concept of "staged anti-crack and layered anti-crack" and can achieve the purpose of anti-crack in the whole process. They made the most effective contribution to concrete from different levels, in different ways and at different times. (3) Triple waterproof mechanism: Self-waterproofing of concrete structure, that is, building waterproofing depends on concrete body, has been proved to be the most fundamental building waterproofing technology. At present, there are three kinds of self-waterproofing measures widely used in structures: compensating shrinkage, enhancing compactness and cracking resistance. SY-K is composed of a variety of functional materials and has the above three waterproof mechanisms, so it has higher impermeability and waterproof ability than a single component. (4) After SY-K products are mixed into concrete, a uniform random support system is formed in concrete by the uniform distribution of a large number of fibers, which produces an effective secondary reinforcement effect and helps to reduce the plastic shrinkage and freeze-thaw stress of concrete. Shrinkage energy is dispersed to tens of millions of fiber monofilaments with high tensile strength and relatively low elastic modulus per cubic meter, thus effectively enhancing the toughness of concrete and inhibiting the generation and development of microcracks. At the same time, the addition of countless fiber monofilaments can effectively hinder the segregation of aggregates, ensure the uniform bleeding of concrete in the early stage, and thus hinder the formation of settlement cracks. Practice has proved that the crack resistance of concrete mixed with this product is 75% higher than that of ordinary concrete; (5) Greatly improve the impermeability and waterproof performance of concrete. Adding a large number of microfibers can effectively inhibit the generation and development of early drying microcracks and segregation cracks in concrete, greatly reduce shrinkage cracks in concrete, especially effectively inhibit the generation of connected cracks. A large number of fibers uniformly distributed in concrete and adhered to each other play the role of "supporting" aggregate, which effectively reduces the separation of water and aggregate on the surface of concrete, thus greatly reducing the content of pores with diameters above 50~ 100 nm and 100 nm in concrete, and greatly improving the impermeability, which is 60% ~ 75% higher than that of ordinary concrete; (6) Enhance the impact resistance and earthquake resistance. After the concrete added with this product is solidified, the high-strength fiber filaments wrapped by cement are bonded together to form a randomly distributed dense mesh reinforcement system, which enhances the fixation of the aggregate by the body, thus improving the wear resistance, helping to prevent and control the generation and development of microcracks, increasing the toughness of concrete/mortar and increasing the ultimate tensile rate. The unique surface treatment technology of fiber products makes the fiber closely combined with cement-based materials, which greatly maintains the overall strength of concrete. When concrete is impacted, the fiber absorbs a lot of energy, thus effectively reducing the role of concentrated stress, hindering the rapid expansion of cracks in concrete, and enhancing the impact resistance and seismic capacity of concrete/mortar; (7) Enhance the frost resistance of concrete. Adding this product to concrete can alleviate the internal stress of concrete caused by temperature change and prevent the generation and expansion of micro-cracks; At the same time, the improvement of concrete impermeability is also beneficial to its frost resistance. This contribution greatly improves the frost resistance of concrete, and can be widely used in cold areas and various mass concrete temperature difference crack control projects.

2. Technical performance (1) dosage: 6% ~10% of the total cementitious materials in concrete; (2) The bleeding rate ratio of concrete is ≤50%, and the permeability height ratio is ≤ 30%; (3) The water absorption rate is ≤65% for 48h, the shrinkage rate is ≤ 125% for 28d, and the compressive strength is not lower than the benchmark concrete; (4) impermeability grade ≥P30, frost resistance grade ≥F200, reducing hydration heat 15% or more; (5) The wear resistance is more than 50% higher than that of the reference concrete; (6) It can effectively improve the impact resistance, earthquake resistance and corrosion resistance of concrete; Can effectively improve the fire resistance of concrete, improve the anti-explosion function of concrete; (7) The product is chlorine-free, non-toxic and harmless, and has no corrosion to steel bars and no pollution to the environment; (8) High-performance concrete with high strength, crack resistance, high elastic modulus, high impermeability, high wear resistance, high impact resistance and high durability can be obtained by using this product; (9) Product color: pink or gray.

The old standard expansion agent can be regarded as cementing material, and it can replace cement with the same amount of expansion agent. However, the expansive agent has no activity after all, and the new standard is to replace the cementing material with the same amount of expansive agent. That is, the amount of each cementing material is multiplied by the mixing coefficient of the expansion agent to obtain the amount of the expansion agent, and finally the amount of each cementing material replaced by the expansion agent is subtracted from the amount of the cementing material. Suppose your total amount of cementitious materials is 500kg, including 400kg of cement, 50kg of fly ash and 50kg of mineral powder. The yield of SY-K is 8%. That is 400*8%=32kg. 50*8%=4kg，50*8%=4kg。 The total amount of expansion agent is 40 kg. 500 * 8% of the total cementitious material = 40kg. The final dosage of cement is 400-32=368kg, fly ash is 50-4=46kg and mineral powder is 50-4=46kg. This is reasonable.