In recent years, China has been accelerating the construction of a modern railway infrastructure system, and constantly enhancing the accessibility and coverage of the railway network. Data show that in the first quarter, the national railway completed fixed assets investment of 113 billion 550 million yuan, an increase of 6.6% over the same period last year.
With the increasing investment of the state in transportation and infrastructure construction, breakthroughs have been made in key and difficult railway projects throughout the country since this year, and a series of railway projects have been started one after another. Railway construction is in full swing, which has played an obvious role in promoting the demand for low-alkali cement .
What is low-alkali cement?
Low-alkali cement refers to the cement with low content of alkali metal oxides (potassium oxide and sodium oxide). The total alkali content is calculated by equivalent sodium oxide (Na2O + 0.658K2O), and the total alkali content (equivalent sodium oxide) of low-alkali cement is required to be less than 0.6%. Compared to other kinds of cement. Low-alkali cement can reduce the risk of alkali-aggregate reaction caused by active aggregate used in concrete to affect the strength of concrete, reduce the amount of water reducing agent used in concrete, increase the workability of concrete, facilitate construction, improve the durability of concrete, and make the concrete look good after solidification. There are many application scenarios
of low-alkali cement, including railway construction. Because high strength concrete is widely used in concrete sleepers, bridges, catenary poles and other railway products, it is necessary to select high strength cement with matching strength grade. In recent years, railway products have higher and higher requirements for cement performance, and the selection of better and better low-alkali cement brands has become a factor that must be measured in construction.
Especially in the construction of high-speed rail, the particularity of high-speed rail engineering technology will inevitably lead to more stringent requirements for the materials used. The special low-alkali cement for high-speed rail is different from the general low-alkali cement we often talk about, not only to meet the national standard GB 175-2007 "General Portland Cement", but also to meet the Chinese railway construction industry standards, referred to as the railway standard, such as TB/T 3275-2018 "Railway Concrete", TB/T 3275-2018 Amendment No.1, and TB/T 3275-2018. TB 10404 — 2018 "Standard for Constructional Quality Acceptance of Railway Concrete Engineering", TB/T 3432 — 2016 "High-speed Railway Prefabricated Post-tensioned Prestressed Concrete Simply Supported Beam". According to the requirements in 3.2.2 of
TB/T 3432 — 2016, low-alkali Portland cement or low-alkali ordinary Portland cement with stable quality and strength grade not less than 42.5 shall be used. The admixture in the cement is limited to ground slag powder or fly ash, the alkali content shall not be greater than 0.6%, the specific surface area shall be 300 ~ 350 m2/kg, the C3A content in the clinker shall not be greater than 8.0%, and the rest of the technology shall conform to the provisions of GB175-2007.
In domestic cement enterprises, there are many enterprises that can provide high-quality low-alkali cement, including Fangcheng County Wanbei Cement (Group) Co., Ltd. located in Nanyang.
It is understood that Wanbei Cement has excellent mine resources and advanced production technology, and has obvious advantages in the development of low-alkali cement. It is widely used in key national projects such as South-to-North Water Transfer Project, Zhengzhou-Wanzhou high-speed rail, Xinyang Minggang Airport, Zhounan Expressway, Xuxin Expressway, Zhengfu high-speed rail and Tianchi Pumped Storage Power Station in Henan Province, which ensures and improves the construction quality of these large-scale projects.
With the support of stable economic policies, transportation and infrastructure construction will remain an important engine for China's economic development. Infrastructure construction is inseparable from cement concrete. Low-alkali cement can greatly improve the durability, reliability and engineering service life of cement concrete, which also brings a very broad market prospect for low-alkali cement. At the same time, in the environment of declining cement demand and overcapacity, creating high-end and differentiated products has become the core competitiveness of cement enterprises.
浙公网安备33010802003254号