高性能混凝土及其在大型桥梁工程中的应用

高性能混凝土(HPC)是在大幅度提高常规混凝土性能的基础上采用现代混凝土技术,选用优质原材料,除水泥、水、集料外,必须掺加足够数量的活性细掺料和高效外加剂的一种新型高技术混凝土,是以耐久性作为设计的主要指标,针对不同用途的要求,对下列性能有重点地加以保证:耐久性、施工性、适用性、强度、体积稳定性和经济性.列举了5个使用C50～C60高性能混凝土的大型桥梁工程,其中有的高性能混凝土能够通过425次冻融循环,有的高性能混凝土具有极高的抗氯离子渗透能力,其56d龄期的电通量仅175C,有的高性能混凝土具有极低的收缩、徐变值.

High Performance Concrete and Its Application to Major Bridges

The high performance concrete (HPC) is a new type high-tech concrete developed on the basis of significant improvement of the performance of conventional concrete and by using the modern concrete techniques including selection of the high quality raw materials, that is, in addition to the cement, water and aggregates, the sufficient amounts of the reactive fine and highly effective admixtures must be added. The durability is the main target in the design of the HPC and in accordance with the requirements for different utilization purposes, the following performance of the HPC, such as the durability, constructability, applicability, strength, volume stability and economic efficiency should be specially ensured. The examples of five major bridges used with the C50~C60 HPC are cited herewith, of which some of the HPC can experience the freezing and thawing cycles more than 425 times, some have the extremely strong ability to resist the permeability of chorine ion with their electric flux at the age of 56 days is merely 175 C and some have very low values of shrinkage and creep.