偏高岭土高性能混凝土的轴压应力-应变关系

采用美国产MTS试验机，研究了掺偏高岭土(Melakaolin，MK)的混凝土轴压应力-应变关系．试验结果表明，随着MK掺量的增加，混凝土的抗压强度随之提高，特别是早期强度提高更为显著．弹性模量略有提高，但幅度明显小于强度提高值．混凝土的韧性得到改善．此外，MK对混凝土的流动性影响较小，且能显著改善粘聚性和保水性．因此，偏高岭土是一种优异的高强高性能混凝土掺合料．

Relationships of uniaxial compressive stress-strain for high performance concrete with metakaolin

Test results show that the compressive strength of concrete increased obviously with the metakaolin replacement increasing, especially for the early strength, about 74 to 84 percent increased at 3 days when metakaolin replacement is 10 to 15 percent. The main mechanisms would be its pozzolanic effect and filling effect. But the compressive elastic modulus increased only a little with the raising of metakaolin replacement. The modulus of concrete is direct ratio to the square root of the compressive strength and the equation has been delivered. The toughness of concrete has been improved based on the analysis of Poisson's ratio and deformation of longitudinal, lateral and volumetric. Furthermore, the effect on workability of concrete was very little and the viscosity and water retentively of concrete has been improved significantly. Therefore, the metakaolin is a very efficient enhancing addition for high performance concrete.