南水北调工程高性能混凝土抗裂技术研究

将现代工程科学最新的并在土木工程其它领域中行之有效的理论、技术、材料、方法应用于大型渡槽设计和施工技术的研究过程之中,同时结合典型工程开展理论分析、模型试验和现场原型试验研究,对当前设计和施工中提出的理论和技术问题给出了科学、经济、合理的解决方法。用课题成果给出的理论和技术体系对现有的大流量预应力渡槽工程进行优化设计和施工,预计可节约投资10%～20%,渡槽单跨经济跨越能力可达30～50m,减震效果可达30%以上,基本上解决渡槽槽身裂缝问题,保证渡槽工程安全运行。

Study on Anti-Crack High Performance Concrete Technique to the South-to-North Water Diversion Project

The quality control indexes of raw materials of high performance concrete were given based on three representative projects (Beishui-gou aqueduct, Fenahuanghe inverted siphon and Caobe earth canal in the South-to-North Water Diversion Project). Control tests of physics, me-chanics, durability, thermal parameters and flexural creep of reinforcement girder of high performance concrete with different mineral admixtures of fly ash, ground slag powder and complex of fly ash and ground slag powder were conducted. The program of fly ash should been adopted for C50W6F200 prestressed concrete of aqueduct body, and the program of fly ash or complex of fly ash and ground slag powder for C30W6F150 con-crete of inverted siphon and C20W6F150 lining concrete of earth canal. The reference mixture parameters of recommendatory concrete were giv-en. The anti-crack ability of the concrete was evaluated by self-repair bending test, drying shrinkage and wetting bulking test, plate cracking test and ring cracking test. The tests indicated concrete with fly ash has good self-repair and anti-crack ability. Some related conclusions and sugges-tions on construction temperature control were given by finite element numerical simulation of crack based on the stru. ctural characteristics of typi-cal engineering, the climate property of the project site, the different placement periods of concrete, the survey of.construction site, analysis of the technical materials of engineering drawings. The dissolution mechanism of heavy metal ions as Cd,Cr, Pb, As, Cu, Zn and Se in concrete and its composite materials were studied. And the effects of those ions on water quality were also studied. The dissolution of harmful heavy metal i-ons is a trace, and less than the maximum limit of related standard.