Developing an Innovative Field Expedient Fracture Toughness Testing Protocol for Concrete Materials

Wang, Jy-An John¹  Liu, Ken C¹  Naus, Dan J¹ 

[1] ORNL

关键词: BUILDING MATERIALS;    CONCRETES;    FRACTURE PROPERTIES;    MECHANICAL TESTS;    MORTARS;    PORTLAND CEMENT;    COMPRESSION STRENGTH fracture toughness;    torsion testing;    spiral notched-groove;    miniature specimen;    mixed-modes fracture;    graphite;    carbon;    composites;    mortar;   

DOI  :  10.2172/949999
RP-ID  :  ORNL/TM-2008/155
PID  :  OSTI ID: 949999
Others  :  TRN: US200910%%132

学科分类：材料科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

The Spiral Notch Torsion Fracture Toughness Test (SNTT) was developed recently to determine the intrinsic fracture toughness (KIC) of structural materials. The SNTT system operates by applying pure torsion to uniform cylindrical specimens with a notch line that spirals around the specimen at a 45 pitch. KIC values are obtained with the aid of a three-dimensional finite-element computer code, TOR3D-KIC. The SNTT method is uniquely suitable for testing a wide variety of materials used extensively in pressure vessel and piping structural components and weldments. Application of the method to metallic, ceramic, and graphite materials has been demonstrated. One important characteristic of SNTT is that neither a fatigue precrack or a deep notch are required for the evaluation of brittle materials, which significantly reduces the sample size requirement. In this paper we report results for a Portland cement-based mortar to demonstrate applicability of the SNTT method to cementitious materials. The estimated KIC of the tested mortar samples with compressive strength of 34.45 MPa was found to be 0.19 MPa m.