In this study, for the purpose of improving the efficiency and accuracy of numerical simulation of massive concrete, the symmetric successive over relaxation-preconditioned conjugate gradient method （SSOR-PCGM） with...In this study, for the purpose of improving the efficiency and accuracy of numerical simulation of massive concrete, the symmetric successive over relaxation-preconditioned conjugate gradient method （SSOR-PCGM） with an improved iteration format was derived and applied to solution of large sparse symmetric positive definite linear equations in the computational process of the finite element analysis. A three-dimensional simulation program for massive concrete was developed based on SSOR-PCGM with an improved iteration format. Then, the programs based on the direct method and SSOR-PCGM with an improved iteration format were used for computation of the Guandi roller compacted concrete （RCC） gravity dam and an elastic cube under free expansion. The comparison and analysis of the computational results show that SSOR-PCGM with the improved iteration format occupies much less physical memory and can solve larger-scale problems with much less computing time and flexible control of accuracy.展开更多
The compressive strength, chloride penetration resistance and microstructure of two high-performance concretes were examined under three curing conditions. Curing conditions include standard curing （SC）, matched cur...The compressive strength, chloride penetration resistance and microstructure of two high-performance concretes were examined under three curing conditions. Curing conditions include standard curing （SC）, matched curing （MC, which means sealed concrete specimens curing at temperature controlled box） and matched curing of naked concrete （NMC） according to development law of temperature measured in mass concrete on site. Results indicate that concrete under MC and NMC show higher resistance to chloride penetration than the one under SC. Concrete under MC has slightly lower chloride penetration than those under NMC, but the compressive strength of specimens under NMC was higher than the one under MC at 56 d. In addition, concrete under NMC and MC have higher early strength than under SC, especially at early age. However, the order of curing conditions affecting compressive strength of concrete at 248 day is： SCNMCMC.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.50808066)
文摘In this study, for the purpose of improving the efficiency and accuracy of numerical simulation of massive concrete, the symmetric successive over relaxation-preconditioned conjugate gradient method （SSOR-PCGM） with an improved iteration format was derived and applied to solution of large sparse symmetric positive definite linear equations in the computational process of the finite element analysis. A three-dimensional simulation program for massive concrete was developed based on SSOR-PCGM with an improved iteration format. Then, the programs based on the direct method and SSOR-PCGM with an improved iteration format were used for computation of the Guandi roller compacted concrete （RCC） gravity dam and an elastic cube under free expansion. The comparison and analysis of the computational results show that SSOR-PCGM with the improved iteration format occupies much less physical memory and can solve larger-scale problems with much less computing time and flexible control of accuracy.
基金Funded by the National Natural Science Foundation of China (No. 50678053)
文摘The compressive strength, chloride penetration resistance and microstructure of two high-performance concretes were examined under three curing conditions. Curing conditions include standard curing （SC）, matched curing （MC, which means sealed concrete specimens curing at temperature controlled box） and matched curing of naked concrete （NMC） according to development law of temperature measured in mass concrete on site. Results indicate that concrete under MC and NMC show higher resistance to chloride penetration than the one under SC. Concrete under MC has slightly lower chloride penetration than those under NMC, but the compressive strength of specimens under NMC was higher than the one under MC at 56 d. In addition, concrete under NMC and MC have higher early strength than under SC, especially at early age. However, the order of curing conditions affecting compressive strength of concrete at 248 day is： SCNMCMC.
