自密实轻骨料混凝土的双K断裂参数和断裂能试验研究  

EXPERIMENTAL STUDY ON DOUBLE-K FRACTURE PARAMETERS AND FRACTURE ENERGY OF SELF-CONSOLIDATING LIGHTWEIGHT CONCRETE

作　　者：吴熙[1] 付腾飞[1] 吴智敏[1] 

机构地区：[1]大连理工大学海岸及近海工程国家重点实验室,辽宁大连116024

出　　处：《工程力学》2010年第A02期249-254,共6页Engineering Mechanics

摘　　要：自密实轻骨料混凝土(Self-consolidating lightweight concrete,SCLC)是一种自重轻,无需振捣的新型混凝土。其工作性能、耐久性能已有少量研究,但SCLC的断裂性能目前未见报道。该文配制了六组不同的缝高比的SCLC三点弯曲梁。通过试验测得的荷载-位移曲线,计算了SCLC的起裂断裂韧度和失稳断裂韧度,并采用边界效应方法计算了真实断裂能。试验表明,SCLC的起裂断裂韧度随试件缝高比增大而增大,失稳韧度则随缝高比的增大而保持常数,为1.17MPa.m1/2。测得的断裂能Gf也随试件缝高比的增大而增大,真实断裂能GF=116.1N/m,过渡韧带长ab*=32.5mm。Self-consolidating lightweight concrete（SCLC） is a new-performance type of concrete which has light self-weight and needs no vibration for compaction.The workability and durability of SCLC have been studied but the fracture properties of SCLC have not been reported yet.Six series of SCLC with different notch/depth ratios were prepared.By means of an experimental load-displacement curve,the initial cracking toughness and unstable fracture toughness were determined and fracture energy was calculated base on a boundary effect model.It is found that the initial cracking toughness increases while the unstable fracture toughness keeps a constant with the increase of the notch/depth ratio.The size-dependent fracture energy increases with the increase of the notch/depth ratio.The specific fracture energy is 116.1N/m,and the ligament length is 32.5mm.

关 键 词：混凝土 自密实轻骨料混凝土 断裂 三点弯曲梁 双K断裂准则 断裂能 边界效应 

分 类 号：TU502[建筑科学—建筑技术科学]