On-going technical committees
The committee of TC-091A is a follow-up of TC-075B on autogenous healing in cementitious materials. The previous committee has just finished its activity. It has published the State-of-Art Report. The report is the first publication on this specific topic in the world. In addition to extensive literature review on the topic, the advanced healing or repairing technologies in Japan are also addressed in the report. However, the part of the research-oriented works has not been satisfactory accomplished during the committee activity. Thus, the evolution of more research-oriented works is remained as the greatest task to the new committee of TC-091A. Therefore, the new committee puts emphasis on the implementation of research works that need practical experiments or measurements on the self-healing properties. The committee consists of about 20 experts from universities and other research institutes of the industry. The whole committee is divided into some task groups for the sake of active works. The following task groups are being planned; Modeling, Design and application, Round-robin tests, Recommendation of testing methods The objective of this committee is as follows;
The door of the committee is open to everybody who is interested in this topic or relating issues. Contribution to the committee through the correspondence is also welcome. We are very pleased to keep in touch with other similar committees in the world.
The bond failure and collapse at anchoring zone of reinforcement leads the brittle behavior of reinforced concrete members. It is difficult to elucidate bond and anchorage behavior because of existence of lots of influencing factors such as transmission of stresses, constitutive laws, continuous failure, and so on. Recently, FEA (Finite Element Analysis) has been popular to observe the behavior of reinforced concrete. However, results of FEA are strongly affected by the assumption of bond and anchorage constitutions. The purpose of the Technical Committee are tidying of previous information about bond and anchorage behavior and the proposal of constitutive laws by points of micro view and adaptability for FEA. The Working Groups which treat discussions about micro bond behavior and application for FEA will be established. The round robin FE analysis will be conducted to investigate adaptabilities of bond constitutive laws for several FEA programs and to grasp sensibilities of varying of the laws to members' behaviors. These conducted subjects will be match with academic investigations, so the symposium including report of the committee will be planed.
Precast concrete products, PCa, are expected to contribute to the sustainable development of the construction, for its' benefit of stable and speedy manufacturing system and availability of using by-product of recycled materials. Especially, in Japan, the Performance-based design methodology and utilization techniques of precast concrete products are strongly required, since Japan is going to be faced the severe problem of population aging and shortage of labor in construction field. From these viewpoints, the Technical Committee on Performance-based Design and Utilization of Precast Concrete Products, JCI-TC-093A, was started to established the performance-based design methodology for precast concrete products and concrete structures assembled by PCa. In addition, this committee aims to make a draft guideline for the design and build of concrete structures used precast concrete products. The committee has two working group, WG1: manufacturing of precast concrete products, which will discuss about the design methodology for precast concrete products, WG2: construction of concrete structures, which will discuss the design methodology for concrete structures using precast concrete products. Moreover, WG1 will discuss about the classification of precast concrete products on the basis of size, purpose of use, design concept, and so on. And WG2 will discuss about the design methodology considering with civil engineering and architecture. The scheme of this committee can be briefly explained as follows; in 2009, both of WG will feasibly study about for making each guideline, and in 2010, describe the draft guideline as the final report. The committee also correlates to the JIS organization for precast concrete products.
First, in this technical committee, performance evaluation techniques for high performance expansive concrete will be precisely investigated to be incorporated into design codes of JSCE or AIJ. Our targets are cracking due to drying shrinkage and due to thermal cracking. Performances of expansive concrete are greatly affected by mix proportion, design, temperature, curing, and, environmental conditions, therefore, based on many past research results, appropriate evaluation techniques will be proposed. Second, in order to diminish harmful cracking, we will try to establish crack controlling system covering the whole process of construction, that is, how to deal with shrinkage in design, quality control of concrete, appropriate construction, and inspection system. In this committee, we will discuss what the real crack control system is, considering the advanced project of Yamaguchi prefecture. Finally, we will check the long-term stability of expansive concrete, and conduct researches for applying expansive additive to blended cements. These results will be published in English to contribute to spreading the technology of expansive concrete to foreign countries.
It is argued, and only consistency in the use with the observance of rule contents or an international standard / the connection laws and ordinances tends I am right, and it to be recognized about a concrete prescribed in Japanese Industrial Standards (JIS)-related quality standards and establishment process and the purpose of the test method or the prescribed original meaning / interpretation such as a matter or the numerical value. In this technical Committee, I understand a concrete-related quality standard and test method definitely and I am aimed and scan those establishment process / purposes and rule contents once again by performing hearing or document investigation and gather right understanding and practical use of the concrete connection technology as a technical documentation of the commentary book to contribute to quality evaluation of the concrete and quality security. In addition, as phase II, I arrange quotation contents in laws and ordinances or the specifications related to a structure or concrete or rule contents and want to inspect the ideal method of various standards and bases / standards to be related to concrete. I make commentary books to understand a concrete-related quality standard and establishment process / a purpose / the rule contents of the test method definitely. This can become an effective technical documentation in JIS original bill making and the reorganization that association of Nippon Concrete engineering carries out, and it can be it in an effective reference book for a university student / an apprentice of go or a young person researcher to understand concrete connection technology through the right understanding such as associated standards definitely.
A main objective of the committee is to clarify properties of concrete under elevated temperature subjected to fire action and relationship between its properties and such performance as load-carrying capacity and deformation of reinforced concrete members through investigation on recent experimental works and analytical activities. Moreover, it is also an important objective to make a state-of-the-art report on design, execution and maintenance of fire-resistant concrete structures through document survey on test methods for fire-resistance of concrete and concrete structures, fire-resistant technologies, and investigation, diagnosis and remedial measure for damaged concrete structures due to fire action. Thereby the activities of the committee can contribute to the progress of fire-resistant technologies.
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JCI-TC-091A Technical Committee on Self Healing / Repairing Technology in Cement-based Materials
