Estimation of Concrete Strength in Structures by the BOSS Method

The Broken-Off Specimens by Splitting - BOSS method was first formulated in 1985 by professor Shirayama of the University of Tsukuba. This new estimation method for concrete strength in structures has been studied subsequently by the authors in terms of practical applications. These included a simplified method and experiments under various conditions to ensure the accuracy of the test method. As a result, a standard test method with a regression equation for estimating the concrete strength in structures was proposed. Compiling these results, this paper deals with a comparative study of BOSS strength and core strength in a full-scale model structure, variance analysis of influences of sampling height and water- cement ratio of concrete on these compressive strength, and applicability of the BOSS method on the basis of these studies. High correlation was found between BOSS and core strength both in normal and high-strength concrete, and the proposed estimation equation was found to be applicable to the reliable evaluation of concrete strength in structures.