粗骨料石粉含量对C50高性能混凝土性能的影响研究

摘要

The influences of stone powder contents in basalt gravel,limestone gravel and crushed pebble aggregates on the workability,mechanical properties and durability of C50 high performance concrete were studied through laboratory test methods.Results show that the slump flow of fresh concrete decreases with the increase of the stone powder content,the cohesion and water retention are also improved; but the flowability reaches the maximum when the stone powder content is 2 ％,then decreases with the increase of stone powder content.The compressive strength and splitting tensile strength of C50 concrete with three kinds of aggregates all first increases,and then decreases with the increase of stone powder content,the compressive strength reaches the maximum when stone powder content is 2 ％; moreover,the splitting tensile strength reaches the maximum when stone powder content is 4％.The type of coarse aggregate has a significant effect on the compressive modulus of elasticity of C50 concrete,the influence level is basalt concrete ＞ limestone concrete ＞ crushed pebble concrete when stone powder content is 4％.While the stone powder content is in the range of 0～6％,the electric flux of C50 concrete with three kinds of coarse aggregates are all below 1 000 C,which indicates the compactness of these concretes are satisfactory.The frost resistance of C50 concrete with 4％ stone powder content presents that basalt is the best while crushed pebble is the worst.%运用室内试验方法,研究玄武岩、石灰岩碎石和碎卵石粗骨料中石粉含量对C50高性能混凝土工作性、力学性能和耐久性的影响.结果表明:新拌混凝土的扩展度随石粉含量的增加而减小,其黏聚性和保水性得到改善,而其流动性在石粉含量为2％时达到最大,之后随石粉含量的增加而减小；3种粗骨料的C50混凝土的抗压强度和劈裂抗拉强度均随石粉含量的增加呈先增大后减小的规律,抗压强度在石粉含量为2％时达到最大,劈裂抗拉强度在石粉含量为4％时达到最大；粗骨料品种对C50混凝土受压弹性模量的影响较大,4％石粉含量C50混凝土受压弹性模量玄武岩混凝土＞石灰岩混凝土＞碎卵石混凝土；石粉含量在0～6％范围内,3种粗骨料的C50混凝土的电通量均在1 000 C以下,混凝土的密实性较好；石粉含量为4％时,玄武岩混凝土的抗冻性最好,碎卵石混凝土的抗冻性最差.