我国寒冷地区每年都有相当长的冬季负温施工期。在混凝土的冬期施工中,以往常采用电热法、暖棚法、蒸汽加热法等费用昂贵的技术措施。近几年来,为了降低建筑工程造价,节约能源,已采用混凝土防冻外加剂来达到混凝土的负温早强,取消保温设施,简化冬期施工的目的。采用混凝土防冻外加剂,主要使低负温下施工的混凝土中液相冰点下降、冰晶畸变、孔结构和孔分布改善、内部结构致密、游离水减少等等,使之减轻或免受冻害。所以,国内已将抗冻剂、早强剂、引气剂、减水剂等多种成分复合使用,借助于各成分的综合效应,达到混凝土抗冻融、早强、抗渗、减水、阻锈等多功能要求,已在冬期施工的工程中取得较好的效果。但是,目前国内大都是使用较紧缺的化工原料亚硝酸钠-硝酸钠为主体的复合型防冻外加剂,这不仅与其它化工产品争原料,而且因其成本成倍提高而增加了建筑工程造价,致使广泛应用这种复合型防冻外加剂受到了限制。因此,开发成本低、货源广、效果好的新型防冻剂是当务之急。现在辉南化肥厂开始生产亚硝酸钙-硝硫钙工业产品,为广泛应用复合型防冻外加剂提供了一种较好的原料。由于我国的水泥品种很多,在使用防冻外加剂时就应考虑水泥的适应性问题。因此,应当根据工程需要、施工工艺设备和方法、冬期施工季节温度、产品性能及其对钢筋蚀锈等情况综合考虑,事先进行外加剂配方的优化设计试验,以获得最佳效果,确保混凝土工程质量。 Every year in the cold regions of China, there is a fairly long negative winter construction period. In the winter construction of concrete, the expensive technical measures such as the electric heating method, the warm greenhouse method, and the steam heating method are often used in the past. In recent years, in order to reduce the cost of construction projects and save energy, concrete antifreeze admixtures have been used to achieve the negative temperature early strength of concrete, the thermal insulation facilities were eliminated, and the purpose of winter construction was simplified. Concrete antifreeze admixtures are used to reduce the liquid-phase freezing point, ice crystal distortion, pore structure and pore distribution improvement, internal structure compaction, and reduction of free water in concrete under low negative temperature, so as to reduce or avoid freezing damage. Therefore, various components such as anti-freeze agents, early strength agents, air-entraining agents, and water-reducing agents have been combined and used in China to achieve anti-freeze-thaw, early-strength, impermeability, and water-reducing effects by virtue of the combined effects of various components. Rust-proof and other multi-functional requirements have achieved good results in the winter construction project. However, at present, most of the domestic use of the compounded antifreeze admixture containing sodium nitrite and sodium nitrate as the main chemical materials, which are relatively scarce, not only competes with other chemical products for raw materials, but also increases the cost of construction projects due to the doubled cost thereof. As a result, the use of such composite antifreeze admixtures has been limited. Therefore, the development of new types of antifreeze with low cost, wide supply, and good results is a top priority. Now Huinan Fertilizer Plant began to produce calcium nitrite-sulfurum calcium industrial products, which provides a good raw material for the extensive application of composite antifreeze admixtures. Since there are many kinds of cement in China, the adaptability of cement should be considered when using antifreeze admixtures. Therefore, based on the engineering needs, construction process equipment and methods, winter construction season temperature, product performance and corrosion rust corrosion, etc., in advance to optimize the design of additive formulations, in order to obtain the best results to ensure the concrete project quality.