Former Graduate Research Assistant, The University of Texas, Austin, TX
L. P. Gilvin Professor in Civil Engineering, The University of Texas, Austin, TX
Director, The Portland Cement Association, Skokie, IL
Pages: 20 Published: Jan 2002
Under the auspices of ASTM Committee C-01, an inter-laboratory study (ILS) was conducted to determine precision and bias for bond-wrench testing carried out under the requirements of ASTM C 1329-98 (“Standard Specification for Mortar Cement”) and ASTM C 1357-98a (“Standard Test Methods for Evaluating Masonry Bond Strength”). The study involved 3 mortars, 15 laboratories and 17 sets of data. Using the statistical analysis procedures of ASTM E 691-99 (“Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method”) and the computer software developed to carry out those procedures, values of intra-laboratory repeatability, r, and inter-laboratory reproducibility, R, were developed. Normalized repeatability decreases from about 30% of the mean tensile bond strength with the least restricted data subsets, to about 20% of the mean tensile bond strength with the most restricted data subsets. Normalized reproducibility decreases from about 60% of the mean tensile bond strength with the least restricted data subsets, to about 40% of the mean tensile bond strength with the most restricted data subsets. Potential factors contributing to repeatability and reproducibility are discussed.
bond-wrench testing, masonry, precision and bias, tensile bond strength
Paper ID: STP11042S