高延性天然水硬性石灰基材料的力学性能

Mechanical Properties of Natural Hydraulic Lime Based Materials with High Ductility

关键词:  天然水硬性石灰  纤维  抗压强度  拉伸性能  裂缝控制

Key words:  natural hydraulic lime  fiber  compressive strength  tensile performance  crack control

摘要:

以天然水硬性石灰和偏高岭土为复合胶凝材料，掺加聚乙烯醇（PVA）纤维、聚乙烯（PE）纤维或玄武岩（BF）纤维，制备了高延性天然水硬性石灰基材料，并研究了其抗压、轴拉力学性能、裂缝控制能力和纤维增强增韧机理. 结果表明：PVA、PE纤维与石英砂或石灰石砂组合均可使水硬性石灰表现出优异的应变硬化和饱和多缝开裂特征，显著提高材料的拉伸强度和极限拉伸应变；PE纤维和石灰石砂组合使材料极限拉伸应变提高至5.604%，PVA纤维和石英砂及石灰石砂组合使材料极限拉伸应变提高至4.000%以上；PVA、PE纤维均可将裂缝宽度控制在100 μm以下，材料在获取超高变形能力的同时具备良好的裂缝控制能力.

Abstract:

The natural hydraulic lime and metakaolin as composite cementitious materials， polyvinyl alcohol （PVA） fibers， polyethylene （PE） fibers， or basalt （BF） fibers were incorporated to prepare the high ductility natural hydraulic lime based materials. The compressive and axial tensile properties， crack control abilities， and the reinforcing and toughening mechanisms of the fibers were experimentally investigated. The results show that the combination of PVA or PE fibers with quartz sand or limestone sand endows the natural hydraulic lime with excellent strain-hardening and saturated multiple-cracking characteristics， and significantly enhances the tensile strength and ultimate tensile strain of materials. The combination of PE fibers and limestone sand increases the ductility materials up to 5.604%， while the joint use of PVA fibers and quartz sand or limestone sand makes the ultimate tensile strain materials increased to more than 4.000%. Both PVA and PE fibers can control the crack width to below 100 μm， adding excellent crack control abilities as well as ultra-high deformation capacity of lime based materials.