HIGH PERFORMANCE ADMIXTURES FOR SELF-COMPACTING CONCRETE : MECHANISM AND APPLICATION IN CHINA BUILDING
In this paper, the basic functional mechanism of high performance admixture (HPA) in SCC is discussed combining with the development of modern concrete admixture. Major applications of JM-SCC in China construction including hydraulic hydropower, transportation and industrial building, such as the Three Gorges Dam, the Gongboxia Hydropower Station, the Nanjing-Hangzhou Express Way, etc. are presented.
Self-compacting concrete. Development, present use and future
Self-compacting concrete was first developed in 1988 in order to achieve durable concrete structures. Since then, various investigations have been carried out and the concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making it a standard concrete. Recommendations and manuals for self-compacting concrete were also established.
ANALYSIS OF BOLT′S ANCHORING QUALITY BASED ON WAVELET NEURAL NETWORK
The dynamic response of bolt achieved by impact-echo method can be effected easily by some factors.It′s difficult to classify bolt′s anchoring quality according to the dynamic response of bolt.In this paper,a new analytical method of bolt′s dynamic response is put forward.The new analytical method combing with advantages of wavelet analysis and artificial neural network is presented.Firstly,the dynamic response of bolt by numerical simulation software FLAC3D is obtained.Secondlyt,he features are extracted from the dynamic response of bolt by wavelet analysis.Thirdlyt,hese features are fed into the artificial neural network for training.Finallyt,his artificial neural network to classify the bolt′s anchoring quality intelligent according to the dynamic response of bolt is employed.In order to validate this new analytical method,some practical signals of bolt′s dynamic response are used for the test.The results indicate that the new analytical method is practicable.