The durability of concrete structures is concerned by many countries in the world. At present, all concrete is compacted by sufficient vibration to meet the required strength and durability. Poor vibration will greatly reduce the final performance of concrete. Therefore, Professor Okamura of Japan proposed to research and develop self-compacting concrete, using its own excellent construction performance, to ensure that concrete can be compacted even under unfavorable construction conditions, to avoid quality defects such as cavities, honeycombs and pitted surfaces caused by insufficient vibration.
They first used the technology of underwater concrete to develop this kind of concrete with good fluidity and high filling property. Through the test, it is found that simply moving this process to the ground is not successful. The main reasons are: a) due to the high viscosity of this kind of concrete, it is difficult to remove the air wrapped in the concrete; B) it is difficult to achieve dense filling in the dense part of the steel bar. Therefore, they began to do new research and made great progress. In 1989, a public trial of self-compacting concrete was held in Tokyo, with the participation of more than 100 researchers and engineers, after which many large construction companies began to develop self-compacting concrete. In 1992, the number of units attending the annual meeting of Japan Concrete Society on self-compacting concrete increased to 30.
Japan Architectural Association has set up a branch of "High Flow Concrete" under the Committee of Materials and Construction, and has studied the quality standards, materials, mix proportions, construction, quality management and other related contents of self-compacting in three years from 1992 to 1995. In January 1997, the "Guidelines for Materials, Mix Proportions, Manufacturing and Construction of High Flow Concrete" was formulated. It has greatly promoted the application of self-compacting concrete in Japan. In August 1998, Japan announced a plan at an international conference that the consumption of self-compacting concrete will exceed 50% of the total consumption of concrete by 2003.
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