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New meIhod of evaluating the compressive s匸rength of concrele in structures using BOSS ： Broken off Sp ime囗s by Sp【 itting Method was developed ． App ］ icabi ］ ity of BOSS sp imen was examined by comparingthe compresslve strength ofspecimens taken from a model structure by coring a ロd by BOSS ， Effeets of water − cement ra［io and the sampling height on compressive streng 山 were studied wi 【 h the variance analysis ． it wasconflrmed tha［high correlation was found between compressive strengths of BOSS and core ． Thus【 he BOSS based simple 『 brmuia may be applicable 【 o the prediction or compressive strength of concrete in st【 uctures ．

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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.

In this paper, a system which employs robots in the automation of construction work is proposed. Specifically, the methodology of a robotized system design in reinforced concrete work are described. Reinforced concrete work involves various works such as mold and reinforcement assembly, concrete placement, straight finish, and mold demolition. The complexity of this work process has been the major obstacle to develop the robotized system. It has been considered difficult to use robots in construction work under the present conditions. Therefore, the development of a drastically reformed construction system was required. In order to accomplish the robotized system for this complex construction work, a consistent system design approach was taken. This approach ranged over a total system design including structural design and construction method design, through the design of many types of robots for use in this system. A new robot modularization was developed, and our own design technology was created.